rpk2 doc

all rpk2 info in this page

Firmware files
Tools for rpk2
basics
TS3USB221 USB Switch and poweroff
bootloaders
replace flash and bootloaders via JTAG and ICSP
1. replace bootloader or flash in Microchip Atmel Studio using ATMEL ICE via JTAG
2. replace bootloader or flash via ICSP USBasp-clone using avrdude
How to program ATMEGA32U4 and AT90USB1287 using Microchip Atmel Studio + USBasp-clone
How to program and debug ATMEGA32U4 and AT90USB1287 via JTAG using Microchip Atmel Studio + ATMEL ICE
How to program ATMEGA32U4 using Arduino IDE + printer bootloader
How to port the previous Arduino Sketch project to Microchip Atmel Studio (better IDE with JTAG Debugging)
How to program AT90USB1287 using Arduino IDE + teensyduino + printer bootloader
How to port the previous Teensy Arduino Sketch project to Microchip Atmel Studio (better IDE with JTAG Debugging)
1. How to JTAG debug the teensy project
demo firmware
ATMEGA32U4 fuses
AT90USB1297 fuses
schematics (MIT LICENSE)
PCB (MIT LICENSE)
BOM

Firmware files

All firmware (.hex and .elf files) + code: https://github.com/therealdreg/rpk2

Tools for rpk2

https://github.com/therealdreg/rpk2/releases/download/tools_rpk2/tools_rpk2.zip

Tools for rpk2 includes:

arduino_modified_rpk2:
atmel-studio-as-installer-7.0.2397-full: Microchip Atmel Studio
zadig-2.6: application that installs generic USB drivers, such as WinUSB, libusb-win32/libusb0.sys or libusbK, to help you access USB devices
Flip Installer 3.4.7.112: Flip supports in-system programming of flash devices through RS232, USB or CAN
JRE Flip Installer 3.4.7.112: Flip with Java Run-time Environment (JRE) integrated
flip_linux_3-2-1: Flip for Linux

basics

rpk2 have a TS3USB221 USB switch + two USB chips inside: ATMEGA32U4 and AT90USB1287

rpk2 USB code is powered by LUFA (thx to Dean Camera), so we can offer you various types of bootloaders and demos

both chips can be programmed via bootloader/ICSP/JTAG

Arduino IDE (including libs) and Microchip Atmel Studio are supported

both chips can be debugged via JTAG in Microchip Atmel Studio (including Arduino projects)

So, YES, you can code and debug your firmware like your C projects in Visual Studio!

ATMEGA32U4 have connected a RFM69HCW 433MHz module:

SX1231 based module with SPI interface
Packet radio with ready-to-go Arduino libraries
+13 to +20 dBm up to 100 mW Power Output Capability (power output selectable in software)
50mA (+13 dBm) to 150mA (+20dBm) current draw for transmissions
Range of approx. 350 meters, depending on obstructions, frequency, antenna and power output
Create multipoint networks with individual node addresses
Encrypted packet engine with AES-128

AT90USB1287 have connected a microSD card reader. AT90USB1287 can poweroff and poweron card reader as needed

AT90USB1287 have connected an external 512Kb RAM AS7C4096A-12TCN

ATMEGA32U4 can poweroff and poweron AT90USB1287 chip as needed

TS3USB221 USB Switch and poweroff

There is only one USB connection, but you can switch between chips as needed (without physical reconnection).

rpk2 have inside a TS3USB221 USB SWITCH chip, this chip is controlled by ATMEGA32U4. So, ATMEGA32U4 can switch USB connection between AT90USB1287 and itself.

By default, the USB connection is connected to ATMEGA32U4.

If you want use AT90USB1287 via USB (bootloader or flash), first you must flash a program in ATMEGA32U4. Example of USB SWITCH: leousbswitchtoat90.hex

AT90USB1287 and ATMEGA32U4 are connected via UART. So, AT90USB1287 can request to ATMEGA32U4 a msg like:

“hey, give me the USB connection”
“I’m done, remove me from the usb connection”
“please, power off me”

bootloaders

Microcontrollers are usually programmed through a programmer unless you have a piece of firmware in your microcontroller that allows installing new firmware without the need of an external programmer. This is called a bootloader

If you want to use the full program space (flash) of the chip or avoid the bootloader delay, you can program rpk2 using an external programmer like ATMEL ICE (ICSP + JTAG) or USBasp (ICSP)

each rpk2 board has pre-programmed a default bootloader for each chip

at90 / leo - bootloaderprinter (default bootloader for both chips)

When you connect a default rpk2 board in bootloader mode via USB is detected as a new Generic Text Only Printer.

This printer is capable of reading and parsing “printed” plain-text Intel HEX files to load firmware onto the AVR

Just open a .hex file with Notepad and print it.

printingfirmware

Now you have the chip programmed with the new firmware. Very easy.

How to activate ATMEGA32U4 bootloader:

press LEO reset button

How to activate AT90USB1287 bootloader:

you must flash leousbswitchtoat90.hex to ATMEGA32U4
reconnect rpk2 board
press AT90 reset + AT90 boot button at same time
stop pressing reset button
wait a little and stop pressing AT90 boot button

at90 / leo - bootloadercdcavr109dude

This bootloader enumerates to the host as a CDC Class device (virtual serial port), allowing for AVR109 protocol compatible programming software to load firmware onto the AVR.

How to program leoblink.hex in ATMEGA32U4 (COM16):

press LEO reset button
open a cmd.exe
use avrdude.exe:

"C:\arduino\hardware\tools\avr\bin\avrdude.exe" -v -v -v -C "C:\arduino\hardware\tools\avr\etc\avrdude.conf" -c AVR109 -p atmega32u4 -P COM16 -U flash:w:"leoblink.hex":i -v -v

How to program at90blink.hex in AT90USB1287 (COM16):

you must flash leousbswitchtoat90.hex to ATMEGA32U4
reconnect rpk2 board
press AT90 reset + AT90 boot button at same time
stop pressing reset button
wait a little and stop pressing AT90 boot button
open a cmd.exe
use avrdude.exe:

"C:\arduino\hardware\tools\avr\bin\avrdude.exe" -v -v -v -C "C:\arduino\hardware\tools\avr\etc\avrdude.conf" -c AVR109 -p at90usb1287 -P COM16 -U flash:w:"at90blink.hex":i -v -v

How to know what COM port use??, just type in cmd.exe:

wmic path Win32_SerialPort get /value

wmic path Win32_SerialPort  where "PNPDeviceID like '%6969%'" get /value

After running this bootloader for the first time on a new computer, may you will need to supply the .INF file located in this demo project’s directory as the device’s driver when running under Windows.

This will enable Windows to use its inbuilt CDC drivers, negating the need for custom drivers for the device.

Other Operating Systems should automatically use their own inbuilt CDC-ACM drivers.

at90 / leo - at90bootloaderdfu

DFU Class device, allowing for DFU-compatible programming software to load firmware onto the AVR.

It spoofs Atmel’s DFU Bootloader USB VID and PID so that the Atmel DFU bootloader drivers included with FLIP will work.

This bootloader is compatible with Atmel’s FLIP utility on Windows machines, and dfu-programmer on Linux machines.

FLIP (Flexible In-System Programmer) is a utility written by Atmel.

The FLIP utility is designed to assist in the bootloader programming of a range of Atmel devices, through several popular physical interfaces including USB.

dfu-programmer is an open-source command line solution for the bootloader programming of Atmel devices through a USB connection, using the DFU protocol, available for download at: https://github.com/dfu-programmer/dfu-programmer

How to program leoblink.hex in ATMEGA32U4 with dfu-programmer:

press LEO reset + LEO boot button at same time
stop pressing reset button
wait a little and stop pressing LEO boot button
open a cmd.exe
use dfu-programmer:

dfu-programmer.exe atmega32u4 get bootloader-version 
dfu-programmer.exe atmega32u4 get BSB
dfu-programmer.exe atmega32u4 erase --force --debug 300
dfu-programmer.exe atmega32u4 flash leoblink.hex --debug 300 
dfu-programmer.exe atmega32u4 launch

How to program at90blink.hex in AT90USB1287 with dfu-programmer:

you must flash leousbswitchtoat90.hex to ATMEGA32U4
reconnect rpk2 board
press AT90 reset + AT90 boot button at same time
stop pressing reset button
wait a little and stop pressing AT90 boot button
open a cmd.exe
use dfu-programmer:

dfu-programmer.exe at90usb1287 get bootloader-version 
dfu-programmer.exe at90usb1287 get BSB
dfu-programmer.exe at90usb1287 erase --force --debug 300
dfu-programmer.exe at90usb1287 flash at90blink.hex --debug 300 
dfu-programmer.exe at90usb1287 launch

If some command fails (The target memory is not blank.), repeat the entire process.

If dfu-programmer dont works try FLIP Software (look next bootloader)

at90usb1287-dfu-1_0_1.hex and atmega32u4-dfu-1_0_0.hex

Official DFU bootloaders from Atmel.

Use DFU Mode in ATMEGA32U4:

press LEO reset + LEO boot button at same time
stop pressing reset button
wait a little and stop pressing LEO boot button

Use DFU Mode in AT90USB1287:

you must flash leousbswitchtoat90.hex to ATMEGA32U4
reconnect rpk2 board
press AT90 reset + AT90 boot button at same time
stop pressing reset button
wait a little and stop pressing AT90 boot button

Just use FLIP Software from ATMEL: https://www.microchip.com/en-us/development-tool/flip

Go to File -> Load HEX File select at90blink.hex or leoblink.hex

Click in Select Target Device Icon

Select AT90USB1287 or ATMEGA32U4

Click in Select a Communication Medium Icon

Select USB and click Open

Select: Erase, Blank Check, Program, Verify

Click Run

Click Start Application (select Reset)

If some fails repeat the entire process.

at90 / leo - bootloaderhid

HID bootloader, allowing for device FLASH programming through the supplied command line software, which is a modified version of Paul’s TeensyHID Command Line loader code from PJRC.

Use HID bootloader in ATMEGA32U4:

press LEO reset + LEO boot button at same time
stop pressing reset button
wait a little and stop pressing LEO boot button

Use HID bootloader in AT90USB1287:

you must flash leousbswitchtoat90.hex to ATMEGA32U4
reconnect rpk2 board
press AT90 reset + AT90 boot button at same time
stop pressing reset button
wait a little and stop pressing AT90 boot button

Check if the bootloader is detected by Windows:

wmic path CIM_LogicalDevice where "DeviceID like '%6969%' and DeviceID like '%HID%'" get /value

Use the python tool to flash at90blink.hex in AT90USB1287:

python hid_bootloader_cli_python.py at90usb1287 at90blink.hex

Use the python tool to flash leoblink.hex in ATMEGA32U4:

python hid_bootloader_cli_python.py atmega32u4 leoblink.hex

Use hid_bootloader_cli_win_vs.exe to flash at90blink.hex in AT90USB1287:

hid_bootloader_cli_win_vs.exe -v -w -mmcu=at90usb1287 at90blink.hex

Use hid_bootloader_cli_win_vs.exe to flash leoblink.hex in ATMEGA32U4:

hid_bootloader_cli_win_vs.exe -v -w -mmcu=atmega32u4  leoblink.hex

For Linux you can use hid_bootloader_cli_unix (the same syntax hid_bootloader_cli_win_vs.exe)

at90 / leo - bootloadermsc

Mass Storage device bootloader, capable of reading and writing a new binary firmware image file, to load firmware onto the AVR.

Use mass storage bootloader in ATMEGA32U4:

press LEO reset + LEO boot button at same time
stop pressing reset button
wait a little and stop pressing LEO boot button

Use mass storage in AT90USB1287:

you must flash leousbswitchtoat90.hex to ATMEGA32U4
reconnect rpk2 board
press AT90 reset + AT90 boot button at same time
stop pressing reset button
wait a little and stop pressing AT90 boot button

Now it appears like a new pendrive connected to the machine:

This bootloader is compatible with all operating systems that support the FAT12 file system format.

To reprogram the device, overwrite a file stored on the virtual FAT filesystem with a new binary (BIN format) image.

Remember to safely remove your device from the host using the host OS’s ejection APIs, to ensure all data is correctly flushed to the bootloader’s virtual filesystem and not cached in the OS’s file system driver.

The current device firmware can be read from the device by reading a file from the virtual FAT filesystem. Two files will be present:

FLASH.BIN representing the AVR’s internal flash memory
EEPROM.BIN representing the AVR’s internal EEPROM memory

To convert an existing Intel HEX (.HEX) program file to a binary (.BIN) file suitable for this bootloader, run:

avr-objcopy -O binary -R .eeprom -R .fuse -R .lock -R .signature input.hex output.bin

AVR EEPROM data files in Intel HEX format (.EEP) uses a similar technique:

avr-objcopy -O binary input.eep output.bin

Example flashing leoblink.hex to ATMEGA32U4:

"C:\arduino\hardware\tools\avr\bin\avr-objcopy.exe" -I ihex leoblink.hex -O binary FLASH.BIN

Copy FLASH.BIN to Mass Storage (replacing the old file)

Eject device (like a pendrive)

Reconnect the board

leobootloaderarduino

This convert ATMEGA32U4 chip to a default Arduino Leonardo. Its a Caterina2 bootloader using LUFA (thx to https://github.com/facchinm/Arduino_avrusb_firmware).

This bootloader spoofs Arduino Leonardo VID and PID values, so the board is detected as Arduino Leonardo.

You can use the Arduino IDE and all libs without problems, also you can upload programs via normal Upload button in Arduino IDE.

replace flash and bootloaders via JTAG and ICSP

To replace a bootloader you need use a ICSP or a JTAG programmer.

These steps are also valid to flash the device without a bootloader.

WARNING: When you burn a flash using JTAG or ICSP the bootloader is removed and only the .hex programmed runs in the chip.

replace bootloader or flash in Microchip Atmel Studio using ATMEL ICE via JTAG

Connect JTAG (in correct position) to chip AVR-JTAG-Connector:

Connect the board to PC

Connect ATMEL ICE to PC

Open Microchip Atmel Studio

Go to Tools -> Device Programming

Select in Tool: Atmel ICE

Select in Device: AT90USB1287 or ATMEGA32U4

Select in Interface: JTAG

Click Apply

Click Read in Device Signature

Now you should read: Reading device ID…OK

Go to Memories

Select Erase device before programming

Select Verify Flash after programming

Select a bootloader .hex file to flash and click Program (the same for the EEPROM)

Now you should read:

Erasing device… OK Programming Flash…OK Verifying Flash…OK

And done, your new bootloader is burned, you can close Microchip Atmel Studio.

replace bootloader or flash via ICSP USBasp-clone using avrdude

Connect your USBasp-clone (in correct position) to ICSP chip (AT90USB1287 or ATMEGA32U4)

Install Zadig Software, Zadig is a Windows application that installs generic USB drivers, such as WinUSB, libusb-win32/libusb0.sys or libusbK, to help you access USB devices:

https://zadig.akeo.ie/

Open Zadig

Go To Options -> List All Devices

Select USBasp

Click in rows and select libusb-win32 driver

Click Replace Driver

run a cmd.exe as Administrator and execute avrdude, example flashing leoblink.hex to ATMEGA32U4:

"C:\arduino\hardware\tools\avr\bin\avrdude.exe" -v -v -v -C "C:\arduino\hardware\tools\avr\etc\avrdude.conf" -c usbasp-clone -p atmega32u4 -P USB -U flash:w:"leoblink.hex":i -v -v

if avrdude fails try again all steps but using libusbK in Zadig:

How to program ATMEGA32U4 and AT90USB1287 using Microchip Atmel Studio + USBasp-clone

Open Microchip Atmel Studio

USBaspLeoDebug

Go Tools –> External Tools

Click Add

Title: USBaspLeoDebug

Command: C:\arduino\hardware\tools\avr\bin\avrdude.exe

Arguments: -v -v -v -C “C:\arduino\hardware\tools\avr\etc\avrdude.conf” -c usbasp-clone -p atmega32u4 -P USB -U flash:w:”$(ProjectDir)\Debug$(TargetName).hex”:i -v -v

Select: Use Output Window

Click OK

USBaspLeoRelease

Go Tools –> External Tools

Click Add

Title: USBaspLeoRelease

Command: C:\arduino\hardware\tools\avr\bin\avrdude.exe

Arguments: -v -v -v -C “C:\arduino\hardware\tools\avr\etc\avrdude.conf” -c usbasp-clone -p atmega32u4 -P USB -U flash:w:”$(ProjectDir)\Release$(TargetName).hex”:i -v -v

Select: Use Output Window

Click OK

USBaspAT90Debug

Go Tools –> External Tools

Click Add

Title: USBaspAT90Debug

Command: C:\arduino\hardware\tools\avr\bin\avrdude.exe

Arguments: -v -v -v -C “C:\arduino\hardware\tools\avr\etc\avrdude.conf” -c usbasp-clone -p at90usb1287 -P USB -U flash:w:”$(ProjectDir)\Debug$(TargetName).hex”:i -v -v

Select: Use Output Window

Click OK

USBaspAT90Release

Go Tools –> External Tools

Click Add

Title: USBaspAT90Release

Command: C:\arduino\hardware\tools\avr\bin\avrdude.exe

Arguments: -v -v -v -C “C:\arduino\hardware\tools\avr\etc\avrdude.conf” -c usbasp-clone -p at90usb1287 -P USB -U flash:w:”$(ProjectDir)\Release$(TargetName).hex”:i -v -v

Select: Use Output Window

Click OK

creating a project for ATMEGA32U4

Go to File –> New –> Project

C/C++ –> GCC C Executable

Click Ok

In Device Family: All

Search and select ATMEGA32U4

Click Ok

Done!

Paste this code in main.c

#define F_CPU 16000000UL

#include <avr/io.h>
#include <util/delay.h>
#include <avr/wdt.h>
#define clear_bit(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#define set_bit(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
#define toogle_bit(sfr, bit) (_SFR_BYTE(sfr) ^= _BV(bit))

int main(int argc, char **argv)
{
    MCUSR &= ~_BV(WDRF);
    wdt_disable();
    
    set_bit(DDRB, DDB5);
    clear_bit(PORTB, PB5);
    set_bit(DDRB, DDB4);
    clear_bit(PORTB, PB4);    

    while (1)
    {
        set_bit(PORTB, PB4);
        _delay_ms(1000);
        set_bit(PORTB, PB5);
        _delay_ms(1000);
        clear_bit(PORTB, PB4);
        clear_bit(PORTB, PB5);
        _delay_ms(200);
        set_bit(PORTB, PB5);
        _delay_ms(1000);
        clear_bit(PORTB, PB4);
        clear_bit(PORTB, PB5);
        _delay_ms(1000);
    }
    
    return 0;
}

Now Compile the project in Debug Mode (Solution Configuration):

Select Debug:

Go to Build –> Rebuild Solution

Now you can see in Output Window:

....
Build succeeded.
========== Rebuild All: 1 succeeded, 0 failed, 0 skipped ==========

Now you have the .hex and .elf output files in the project folder:

project_name\project_name\Debug\project_name.hex

To Open the project Directory right click in Solution –> Open Folder in File Explorer

You can flash it via bootloader, JTAG, ICSP ..

Now, connect USBasp in correct order to rpk2.

Connect rpk2 to PC.

Connect USBasp to PC.

Go to Tools –> USBaspLeoDebug

Also you can compile in Release mode and for flash it just use Tools –> USBaspLeoRelease

Example of correct avrdude output (USBaspLeoRelease):

creating a project for AT90USB1287

Go to File –> New –> Project

C/C++ –> GCC C Executable

Click Ok

In Device Family: All

Search and select AT90USB1287

Click Ok

Done!

Paste this code in main.c

#define F_CPU 16000000UL

#include <avr/io.h>
#include <util/delay.h>
#include <avr/wdt.h>
#include <avr/sfr_defs.h>
#define clear_bit(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#define set_bit(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
#define toogle_bit(sfr, bit) (_SFR_BYTE(sfr) ^= _BV(bit))

int main(int argc, char **argv)
{
    MCUSR &= ~_BV(WDRF);
    wdt_disable();

    CLKPR = (1<<CLKPCE);
    CLKPR = 0;
    
    set_bit(DDRD, DDD6);
    clear_bit(PORTD, PD6);
    set_bit(DDRD, DDD7);
    clear_bit(PORTD, PD7);

    while (1)
    {
        set_bit(PORTD, PD6);
        _delay_ms(1000);
        set_bit(PORTD, PD7);
        _delay_ms(1000);
        clear_bit(PORTD, PD6);
        clear_bit(PORTD, PD7);
        _delay_ms(200);
        set_bit(PORTD, PD7);
        _delay_ms(1000);
        clear_bit(PORTD, PD6);
        clear_bit(PORTD, PD7);
        _delay_ms(1000);
    }
    
    return 0;
}

Now Compile the project in Debug Mode (Solution Configuration):

Select Debug:

Go to Build –> Rebuild Solution

Now you can see in Output Window:

....
Build succeeded.
========== Rebuild All: 1 succeeded, 0 failed, 0 skipped ==========

Now you have the .hex and .elf output files in the project folder:

project_name\project_name\Debug\project_name.hex

To Open the project Directory right click in Solution –> Open Folder in File Explorer

You can flash it via bootloader, JTAG, ICSP ..

Now, connect USBasp in correct order to rpk2.

Connect rpk2 to PC.

Connect USBasp to PC.

Go to Tools –> USBaspAT90Debug

Also you can compile in Release mode and for flash it just use Tools –> USBaspAT90Release

How to program and debug ATMEGA32U4 and AT90USB1287 via JTAG using Microchip Atmel Studio + ATMEL ICE

Open the solution project (.atsln)

Select Debug to compile

Go to Debug -> Start Debugging and break

Press Continue in the message box

Selected debugger / programmer: Atmel-ICE

Interface: JTAG (if you want use ICSP connector only for programming select ISP)

Go to File -> Save All

Go to Debug -> Start Debugging and break

and done, You can debug your project, put breakpoints etc.

To flash a Release version or Debug version without Debugging just go to Debug -> Start Without Debugging

For flash also you can use ATMEL-ICE ICSP connector

How to program ATMEGA32U4 using Arduino IDE + printer bootloader

Open Arduino IDE

Go to File –> New

Paste this code:

#define LED1 8
#define LED2 9

void initVariant(void) 
{
  //modified by Dreg
  asm volatile ("sbi 0x10,0");
  asm volatile ("cbi 0x11,0");
  asm volatile ("sbi 0x10,1");
  asm volatile ("sbi 0x11,1");
  // -
}

void setup() 
{
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  
  delay(1000);
} 

void loop() 
{
  digitalWrite(LED1, HIGH);
  delay(500);
  digitalWrite(LED2, HIGH);
  delay(500);
  digitalWrite(LED1, LOW);
  delay(500);
  digitalWrite(LED2, LOW);
  delay(500);
}

Go to File -> Save

Now, Go Tools -> Board –> Arduino AVR Boards —> Arduino Leonardo

Go to Sketch –> Export Compiled Binary

Open Sketch folder

Open sketch_name.ino.leonardo with Notepad

Enable bootloader mode in ATMEGA32U4

Print it!

Done!

How to port the previous Arduino Sketch project to Microchip Atmel Studio (better IDE with JTAG Debugging)

Open Microchip Atmel Studio

Go to File —> New —> Project

Select Create Project From Arduino Sketch

Click Ok

Select Sketch File

Select your Arduino Installation Path

Board: Arduino Leonardo

Device: atmega32u4

Click Ok

Done!

Now you can build the project

Go to Build –> Rebuild Solution

Now you have the .hex file in:

sketch_name\sketch_name\sketch_name\Debug\sketch_name.hex

or:

sketch_name\sketch_name\sketch_name\Release\sketch_name.hex

You can print it in bootloader mode or flash it directly from Microchip Atmel Studio using JTAG (or ICSP via Atmel ICE)

Now you can debug this project like a normal project.

How to program AT90USB1287 using Arduino IDE + teensyduino + printer bootloader

Open Arduino IDE with teensyduino previously installed: https://www.pjrc.com/teensy/td_download.html

Go to File –> New

Paste this code:

#define LED1 6
#define LED2 7

#include <avr/io.h>
#include <avr/wdt.h>

int InitAT90(void)
{
    MCUSR &= ~(1<<WDRF);
    wdt_disable();
    CLKPR = (1<<CLKPCE);
    CLKPR = 0;
    return 1;
}

void initVariant(void) 
{
  InitAT90();
  delay(3000);
}

void setup() 
{
  InitAT90();
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
}

void loop() 
{
  digitalWrite(LED1, HIGH);   
  delay(500);                     
  digitalWrite(LED2, HIGH); 
  delay(500);  
  digitalWrite(LED2, LOW);  
  delay(500);                       
  digitalWrite(LED1, LOW);
  delay(500);
}

Go to File -> Save

Now, Go Tools -> Board –> Teensyduino —> Tennsy++ 2.0

Go to Sketch –> Export Compiled Binary

Open Sketch folder

Open sketch_name.ino.TEENSY2PP.hex with Notepad

Enable bootloader mode in AT90USB1287

Print it!

Done, you can use Tennsy++ 2.0 libs in Arduino! https://www.pjrc.com/teensy/td_libs.html

How to port the previous Teensy Arduino Sketch project to Microchip Atmel Studio (better IDE with JTAG Debugging)

You need install Visual Micro in Microchip Atmel Studio: https://www.visualmicro.com/

Open Microchip Atmel Studio

Go to Tools -> Extensions and Updated

Go to online

Search Arduino

Download and Install Visual Micro:

restart Microchip Atmel Studio

Go to File –> Open —> Arduino Project

Search the Teensy Arduino Sketch project

Go to Build –> Rebuild Solution

And now you have the .hex ready to flash in: sketch_name\Release\sketch_name.hex or: sketch_name\Debug\sketch_name.hex

Open sketch_name.ino.hex with Notepad

Enable bootloader mode in AT90USB1287

Print it!

Now save the Microchip Atmel Studio Project, Go to File –> Save all

How to JTAG debug the teensy project

You need create other project only for debugging

Go to File –> Open —> Open Object File For Debugging

Select the Object File To Debug: Search sketch_name\Debug\sketch_name.elf

Click Next

Select device AT90USB1287

Click Finish

Click Finish again

Go to Debug –> Start Debugging and Brak

And done you can use this project only for debugging via JTAG

demo firmware

All LUFA + own demos adapted for rpk2 (some demos are not 100% adapted yet, but it works)

at90audioinput

Audio demonstration application.

This gives a simple reference application for implementing a USB Audio Input device using the basic USB Audio 1.0 drivers in all modern OSes (i.e. no special drivers required).

On start-up the system will automatically enumerate and function as a USB microphone.

By default, the demo will produce a square wave test tone when the board button is pressed.

If USE_TEST_TONE is not defined in the project makefile, incoming audio from the ADC channel 1 will be sampled and sent to the host computer instead.

When in microphone mode, connect a microphone to the ADC channel 2.

at90audiooutput

Audio demonstration application.

This gives a simple reference application for implementing a USB Audio Output device using the basic USB Audio 1.0 drivers in all modern OSes (i.e. no special drivers required).

On start-up the system will automatically enumerate and function as a USB speaker.

Outgoing audio will output in 8-bit PWM onto the timer 3 output compare channel A for AUDIO_OUT_MONO mode, on timer 3 channels A and B for AUDIO_OUT_STEREO and on PORTC as a signed mono sample for AUDIO_OUT_PORTC.

Audio output will also be indicated on the board LEDs in all modes. Decouple audio outputs with a capacitor and attach to a speaker to hear the audio.

at90dualmidi

Dual MIDI demonstration application. This gives a simple reference application for implementing the USB-MIDI class in USB devices.

It is built upon the USB Audio class.

Joystick movements are translated into note on/off messages and are sent to the host PC as MIDI streams which can be read by any MIDI program supporting MIDI IN devices.

If the HWB is not pressed, the first virtual MIDI cable to the host is used.

If the HWB is pressed, then the second virtual cable is selected.

This device implements MIDI-THRU mode, with the IN MIDI data being generated by the device itself.

OUT MIDI data is discarded.

at90dualvirtualserial

Dual Communications Device Class demonstration application.

This gives a simple reference application for implementing a composite device with dual CDC functions acting as a pair of virtual serial ports.

This demo uses Interface Association Descriptors to link together the pair of related CDC descriptors for each virtual serial port, which may not be supported in all OSes - Windows Vista is supported, as is XP (although the latter may need a hotfix to function).

Joystick actions are transmitted to the host as strings through the first serial port.

The device does not respond to serial data sent from the host in the first serial port.

The second serial port echoes back data sent from the host.

After running this demo for the first time on a new computer, may you will need to supply the .INF file located in this demo project’s directory as the device’s driver when running under Windows.

This will enable Windows to use its inbuilt CDC drivers, negating the need for custom drivers for the device.

Other Operating Systems should automatically use their own inbuilt CDC-ACM drivers.

at90ethernet

Remote Network Driver Interface demonstration application.

This gives a simple reference application for implementing a CDC RNDIS device acting as a simple network interface for ethernet packet exchange.

RNDIS is a proprietary Microsoft standard;

this demo will only work on Windows 2000 (manually patched with the Microsoft RNDIS hotfix) and above (with no manual patches), or on the latest Linux kernels.

Before running, you will need to install the INF file that is located in the project directory.

This will enable Windows to use its inbuilt RNDIS drivers, negating the need for special Windows drivers for the device.

To install, right-click the .INF file and choose the Install option.

If Windows 2000 is used, the Microsoft INF file in the hotfix will need to be altered to use the VID/PID of the demo and then chosen instead of the LUFA RNDIS INF file when prompted.

When enumerated, this demo will install as a new network adapter which ethernet packets can be sent to and received from.

Running on top of the adapter is a very simple TCP/IP stack with a HTTP webserver and TELNET host which can be accessed through a web browser at IP address 10.0.0.2:80 or through a TELNET client at 10.0.0.2:25.

This device also supports ping echos via the ICMP protocol.

The TCP/IP stack in this demo has a number of limitations and should serve as an example only - it is not fully featured nor compliant to the TCP/IP specification.

For complete projects, it is recommended that it be replaced with an external open source TCP/IP stack that is feature complete, such as the uIP stack.

at90generichid

Generic HID device demonstration application.

This gives a simple reference application for implementing a generic HID device, using the basic USB HID drivers in all modern OSes (i.e. no special drivers required).

By default it accepts and sends up to 8 byte reports to and from a USB Host, and transmits the last sent report back to the host.

On start-up the system will automatically enumerate and function as a vendor HID device.

When controlled by a custom HID class application, reports can be sent and received by both the standard data endpoint and control request methods defined in the HID specification.ers required).

By default it accepts and sends up to 8 byte reports to and from a USB Host, and transmits the last sent report back to the host.

On start-up the system will automatically enumerate and function as a vendor HID device.

When controlled by a custom HID class application, reports can be sent and received by both the standard data endpoint and control request methods defined in the HID specification.

Just connect the board and execute one of the programs:

test_generic_hid_libusb.js
test_generic_hid_winusb.py
test_generic_hid_libusb.py

at90keyboard

Keyboard demonstration application. This gives a simple reference application for implementing a USB Keyboard using the basic USB HID drivers in all modern OSes (i.e. no special drivers required).

It is boot protocol compatible, and thus works under compatible BIOS as if it was a native keyboard (e.g. PS/2).

On start-up the system will automatically enumerate and function as a keyboard when the USB connection to a host is present.

To use the keyboard example, manipulate the joystick to send the letters a, b, c, d and e.

See the USB HID documentation for more information on sending keyboard event and key presses.

Unlike other LUFA Keyboard demos, this example shows explicitly how to send multiple key presses inside the same report to the host.

at90keyboardmouse

Keyboard/Mouse demonstration application, using a single HID interface.

This gives a simple reference application for implementing a multiple HID report device containing both USB Keyboard and USB Mouse functionality using the basic USB HID drivers in all modern OSes (i.e. no special drivers required).

This example uses a single HID interface that is shared between the two functions.

On start-up the system will automatically enumerate and function as a keyboard when the USB connection to a host is present and the HWB is not pressed.

When enabled, manipulate the joystick to send the letters a, b, c, d and e.

See the USB HID documentation for more information on sending keyboard event and key presses.

When the HWB is pressed, the mouse mode is enabled.

When enabled, move the joystick to move the pointer, and push the joystick inwards to simulate a left-button click.

at90keyboardmousenomulti

Keyboard/Mouse demonstration application.

This gives a simple reference application for implementing a composite device containing both USB Keyboard and USB Mouse functionality using the basic USB HID drivers in all modern OSes (i.e. no special drivers required).

This example uses two separate HID interfaces for each function.

It is boot protocol compatible, and thus works under compatible BIOS as if it was a native keyboard and mouse (e.g. PS/2).

On start-up the system will automatically enumerate and function as a keyboard when the USB connection to a host is present and the HWB is not pressed.

When enabled, manipulate the joystick to send the letters a, b, c, d and e.

See the USB HID documentation for more information on sending keyboard event and key presses.

When the HWB is pressed, the mouse mode is enabled. When enabled, move the joystick to move the pointer, and push the joystick inwards to simulate a left-button click.

at90midi

MIDI demonstration application.

This gives a simple reference application for implementing the USB-MIDI class in USB devices.

It is built upon the USB Audio class.

Joystick movements are translated into note on/off messages and are sent to the host PC as MIDI streams which can be read by any MIDI program supporting MIDI IN devices.

If the HWB is not pressed, channel 1 (default piano) is used.

If the HWB is pressed, then channel 10 (default percussion) is selected.

This device implements MIDI-THRU mode, with the IN MIDI data being generated by the device itself. OUT MIDI data is discarded.

at90mouse

Mouse demonstration application.

This gives a simple reference application for implementing a USB Mouse using the basic USB HID drivers in all modern OSes (i.e. no special drivers required).

It is boot protocol compatible, and thus works under compatible BIOS as if it was a native mouse (e.g. PS/2).

On start-up the system will automatically enumerate and function as a mouse when the USB connection to a host is present.

To use the mouse, move the joystick to move the pointer, and push the joystick inwards to simulate a left-button click.

The HWB serves as the right mouse button.

at90virtualserial

Communications Device Class demonstration application.

This gives a simple reference application for implementing a CDC device acting as a virtual serial port.

Joystick actions are transmitted to the host as strings.

The device does not respond to serial data sent from the host.

After running this demo for the first time on a new computer, may you will need to supply the .INF file located in this demo project’s directory as the device’s driver when running under Windows.

This will enable Windows to use its inbuilt CDC drivers, negating the need for custom drivers for the device.

Other Operating Systems should automatically use their own inbuilt CDC-ACM drivers.

at90masskeyboardfatfs - at90masskeyboard2gbsd - at90masskeyboardvirtualserialfatfs - at90masskeyboardvirtualserial2gbsd

Combined Mass Storage and Keyboard demonstration application.

This gives a simple reference application for implementing a dual class USB Mass Storage and USB HID Keyboard device using the basic USB UFI and HID drivers in all modern OSes (i.e. no special drivers required).

On start-up the system will automatically enumerate and function as an external mass storage device (which may be formatted and used in the same manner as commercial USB Mass Storage devices) and a USB keyboard.

You will need to format the mass storage drive upon first run of this demonstration - as the device acts only as a data block transport between the host and the storage media, it does not matter what file system is used, as the data interpretation is performed by the host and not the USB device.

Keys on the USB keyboard can be pressed by moving the board’s Joystick.

The USB control endpoint is managed entirely by the library using endpoint interrupts, as the INTERRUPT_CONTROL_ENDPOINT option is enabled.

This allows for the host to reset the Mass Storage device state during long transfers without the need for complicated polling logic.

demos with virtualserial string inside adds a CDC device acting as a virtual serial port:

mass storage +
keyboard +
virtual serial port

demos with 2gbsd string inside only works with 2 GB SD CARDS (not SDHC)

at90extmem

Example using and testing external memory 512Kb RAM AS7C4096A-12TCN

at90readwritespisd

Example using a 2 GB SD CARDS (not SDHC) via SPI

at90serialhello

Example hello world via chip UART. Pins accesible in rpk2 board

at90softuartx

Example using software UART only for transmit (using PB5)

at90swuart

Software UART for AVR like AltSoftSerial or NeoICSerial without Arduino layer

This library is like AltSoftSerial:

Can simultaneously transmit and receive. Minimal interference with simultaneous use of HardwareSerial and other libraries
Consumes a 16 bit timer (and will not work with any libraries which need that timer) and disables some PWM pins
Its possible to switch between TIMER1 and TIMER3 with a simple #define
Can be sensitive to interrupt usage by other libraries
Capable of running up to 31250 baud on 16 MHz AVR. Slower baud rates are recommended when other code may delay library’s interrupt response
More info about Interrupt Latency Requirements, Timer Usage, Usable Speed: https://www.pjrc.com/teensy/td_libs_AltSoftSerial.html

https://github.com/therealdreg/at90swuart

at90timers

Example using TIMER1 and TIMER3 (both 16 timers) generating a 100 Hz delay. (needed by FatFs).

at90buttons

Example using buttons and leds in the rpk2 board.

at90blink

Blink leds in the rpk2 board.

at90sketchbasicexample

Example programming AT90USB1287 board with Arduino + Teensyduino

In Arduino IDE:

Go to Tools –> Board –> Teensyduino –> Teensy++ 2.0

USB Type: Serial

CPU SPEED: 16mhz

leoaltsoftserial

Software UART AltSoftSerial

Can simultaneously transmit and receive. Minimal interference with simultaneous use of HardwareSerial and other libraries
Consumes a 16 bit timer (and will not work with any libraries which need that timer) and disables some PWM pins
Its possible to switch between TIMER1 and TIMER3 with a simple #define
Can be sensitive to interrupt usage by other libraries
Capable of running up to 31250 baud on 16 MHz AVR. Slower baud rates are recommended when other code may delay library’s interrupt response
More info about Interrupt Latency Requirements, Timer Usage, Usable Speed: https://www.pjrc.com/teensy/td_libs_AltSoftSerial.html

leoblink

Blink leds in the rpk2 board.

leobuttons

Example using buttons and leds in the rpk2 board.

leohellowkeyboard

Demo using ATMEGA32U4 like a Keyboard

leorfrecver

Demo using RFM69HCW 433MHz module as a reciver module

leosketchbasicexample

Example of Arduino Sketch for ATMEGA32U4

leousbswitchtoat90

Example of how to use USB SWITCH

leoencchat

AES encrypted RF chat between rpk2 board & feather 32u4

By Jusepe @itasahobby

leowinbondflashdriver

A generic driver + sample of usage for W25Q512JV flash memory over SPI using ATmega32u4

By Jusepe @itasahobby winbond_flash_driver

adafruit_feather_32u4 demos

Demos for Adafruit Feather 32u4 using RFM69HCW 433MHz module as a sender or reciver module

adafruit_feather_32u4_rf_leoencchat

AES encrypted RF chat between rpk2 board & feather 32u4

By Jusepe @itasahobby

evilmass

Evil Mass Storage is a proof of concept USB composite device which demonstrates an end-to-end solution that infiltrates an isolated-offline-network and covertly extracts data over both radio frequency or close access covert storage while hiding from forensic analysis.

info: evil mass storage

ATMEGA32U4 fuses

(factory: ex 0xF3, hi 0x99, lo 0x5E)

extended: 0xcb
high: 0x98
low: 0xff

AT90USB1297 fuses

(factory: ex 0xF3, hi 0x99, lo 0x5E)

extended: 0xf3
high: 0x91
low: 0x5e

schematics (MIT LICENSE)

rpk2 v3

USB SWITCH + POWER

LEO

AT90

PCB (MIT LICENSE)

BOM

ID	Name	Designator	Footprint	Quantity	Manufacturer Part	Manufacturer	Supplier	Supplier Part	Price
U-USBAR04P-M002	USB_PC	USB-A-TH_U-USBAR04P-M002	1	U-USBAR04P-M002	Shenzhen Cankemeng	LCSC	C386753	0.082
HDR-M-2.54_1x3	DEBUG_AT90	HDR-M-2.54_1X3	1			LCSC	C180248	0.236
HDR-M-2.54_1x5	J1	HDR-M-2.54_1X5	1			LCSC	C358687	0.022
AT90USB1287-AU	U4	TQFP-64_L14.0-W14.0-P0.80-LS14.0-BL	1	AT90USB1287-AU	MICROCHIP(美国微芯)	LCSC	C1337397	14.2
47uF	C33	CAP-SMD_BD5.0-L5.3-W5.3-FD	1	OVZ470M1A0506-TRO	Lelon	LCSC	C250111	0.183
HDR-M-2.54_1x4	"PWR3,PWR5,PWRGND"	HDR-M-2.54_1X4	3			LCSC	C124378	0.028
ICSP	"ICSP1,ICSP"	HDR-M-2.54_2X3	2			LCSC	C132438	0.15
K2-1107ST-A4SW-06	"LEO_BOOT,AT_BOOT,AT_RES,LEO_RES,LEO_USER,USER_AT90"	KEY-SMD_L6.2-W3.6-LS8.0	6	K2-1107ST-A4SW-06	Rectangular Connectors - Contacts	LCSC	C118141	0.056
47K	"R39,R24,R25"	R0603	3	0603WAF4702T5E	UniOhm	LCSC	C25819	0.001
FC-2012HRK-620D	"LED3V3,LEDSD"	LED0805-RD_RED	2	FC-2012HRK-620D	NATIONSTAR	LCSC	C84256	0.012
19-217/GHC-YR1S2/3T	"LED5V,LEDAT90"	LED0603-R-RD	2	19-217/GHC-YR1S2/3T	EVERLIGHT	LCSC	C72043	0.027
E6C0606RYGC2UDA	"LEDBIAT90,LEDBILEO"	LED-SMD_4P-L1.6-W1.6-BL-RD	2	E6C0606RYGC2UDA	EKINGLUX	LCSC	C375543	0.036
51K	"R38,R37"	R0603	2	0603WAF5102T5E	UniOhm	LCSC	C23196	0.001
16MHz	X2	OSC-SMD_4P-L3.2-W2.5-BL	1	X322516MLB4SI	YXC	LCSC	C13738	0.084
1K	"R5,R21"	R0603	2	0603WAF1001T5E	UniOhm	LCSC	C21190	0.001
15pF	"C21,C22"	C0603	2	CL10C150JB8NNNC	SAMSUNG	LCSC	C1644	0.006
ATMEGA32U4-AU	U2	TQFP-44_L10.0-W10.0-P0.80-LS12.0-BL	1	ATMEGA32U4-AU	MICROCHIP(美国微芯)	LCSC	C44854	7.026
HDR-M-2.54_1x1	ANTENA	HDR-M-2.54_1X1	1	712-ANT-433-HETH	Linx Technologies	Mouser	712-ANT-433-HETH	1.8
BSMD0805-035-24V	F1	FUSE-SMD_L2.1-W1.4-1	1			LCSC	C910821	0.053
470uF	"C32,C3,C2"	CAP-SMD_BD10.0-L10.3-W10.3-RD	3	OVZ471M1A1008-TRO	Lelon	LCSC	C250114	0.28
SN74AHC573DWR	U7	SOP-20_L12.8-W7.5-P1.27-LS10.4-BL	1	SN74AHC573DWR	TI	LCSC	C58204	0.245
1uF	"C1,C10,C12,C26"	C0805	4	CL21B105KBFNNNE	SAMSUNG	LCSC	C28323	0.01
22pF	"C4,C5"	C0603	2	CL10C220JB8NNNC	SAMSUNG	LCSC	C1653	0.004
100nF	"C6,C7,C8,C9,C11,C13,C14,C15,C17,C18,C19,C20,C24,C25,C27,C28,C29,C30,C31"	C0603	19	CC0603KRX7R9BB104	YAGEO	LCSC	C14663	0.002
10uF	C16	C1206	1	CL31A106KBHNNNE	SAMSUNG	LCSC	C13585	0.033
220nF	C23	C0603	1	CL10B224KA8NNNC	SAMSUNG	LCSC	C21120	0.006
TF-01A	CARD1	TF-SMD_TF-01A	1	TF-01A	HRO	LCSC	C91145	0.167
SM4007PL	D2	SOD-123F_L2.8-W1.8-LS3.7-RD	1	SM4007PL	MDD	LCSC	C64898	0.008
"BZX585-B3V6,115"	"D3,D4,D5"	SOD-523_L1.2-W0.8-LS1.6-RD	3	"BZX585-B3V6,115"	Nexperia	LCSC	C455026	0.042
AVR-JTAG-10-5103309-1	"JP1,JP2"	HDR-5103309-1	2			LCSC	C5665	0.06
30Ω	L2	L0603	1	PBY160808T-300Y-N	Chilisin	LCSC	C142075	0.004
MMBT2222A_C916372	"Q1,Q4"	SOT-23-3_L2.9-W1.3-P1.90-LS2.4-BR	2	MMBT2222A	JSMSEMI	LCSC	C916372	0.01
IRLML6402_C518785	"Q2,Q3"	SOT-23-3_L2.9-W1.3-P1.90-LS2.4-BR	2	IRLML6402	HUASHUO	LCSC	C518785	0.054
1K	"R1,R6"	R0805	2	0805W8F1001T5E	UniOhm	LCSC	C17513	0.002
3.3K	"R2,R9"	R0805	2	0805W8F3301T5E	UniOhm	LCSC	C26010	0.002
10K	"R3,R10"	R0805	2	ERJ6ENF1002V	PANASONIC	LCSC	C169253	0.008
22	"R4,R11,R27,R28"	R0603	4	0603WAF220JT5E	UniOhm	LCSC	C23345	0.001
470	"R7,R8,R20,R22,R23"	R0603	5	0603WAF4700T5E	UniOhm	LCSC	C23179	0.001
10K	"R12,R15,R16,R17,R19"	R0603	5	0603WAF1002T5E	UniOhm	LCSC	C25804	0.001
1M	R13	R0603	1	0603WAF1004T5E	UniOhm	LCSC	C22935	0.001
0	"R14,R18,R26"	R0603	3	0603WAF0000T5E	UniOhm	LCSC	C21189	0.001
820	"R29,R30,R31,R32,R33,R34,R35,R36"	R0603	8	0603WAF8200T5E	UniOhm	LCSC	C23253	0.001
TS3USB221DRCR	U1	VSON-10_L3.0-W3.0-P0.50-TL-EP_TPS62410DRCR	1	TS3USB221DRCR	Texas Instruments	LCSC	C324071	1.038
AS7C4096A-12TCN	U5	TSOP44-II	1	AS7C4096A-12TCN	Alliance Memory	LCSC	C1348896	6.6
CD74HC4050PWR	"U6,U9"	TSSOP-16_L5.0-W4.4-P0.65-LS6.4-BL	2	CD74HC4050PWR	Texas Instruments	LCSC	C352825	0.29
RFM69HCW	U8	RFM69HCW-XXXS2	1	RFM69HCW	hoperf	Mouser	474-COM-13910	5.21
16MHz	X1	HC-49S_L11.4-W4.8	1	X49SM16MSD2SC	YXC	LCSC	C12676	0.073
K7803M-1000R3	U10	PWRM-TH_K78XXM-1000R3	1	K7803M-1000R3	MORNSUN	LCSC	C132363	3.695

rpk2 doc

Table of contents

Firmware files

Tools for rpk2

basics

TS3USB221 USB Switch and poweroff

bootloaders

at90 / leo - bootloaderprinter (default bootloader for both chips)

at90 / leo - bootloadercdcavr109dude

at90 / leo - at90bootloaderdfu

at90usb1287-dfu-1_0_1.hex and atmega32u4-dfu-1_0_0.hex

at90 / leo - bootloaderhid

at90 / leo - bootloadermsc

leobootloaderarduino

replace flash and bootloaders via JTAG and ICSP

replace bootloader or flash in Microchip Atmel Studio using ATMEL ICE via JTAG

replace bootloader or flash via ICSP USBasp-clone using avrdude

How to program ATMEGA32U4 and AT90USB1287 using Microchip Atmel Studio + USBasp-clone

USBaspLeoDebug

USBaspLeoRelease

USBaspAT90Debug

USBaspAT90Release

creating a project for ATMEGA32U4

creating a project for AT90USB1287

How to program and debug ATMEGA32U4 and AT90USB1287 via JTAG using Microchip Atmel Studio + ATMEL ICE

How to program ATMEGA32U4 using Arduino IDE + printer bootloader

How to port the previous Arduino Sketch project to Microchip Atmel Studio (better IDE with JTAG Debugging)

How to program AT90USB1287 using Arduino IDE + teensyduino + printer bootloader

How to port the previous Teensy Arduino Sketch project to Microchip Atmel Studio (better IDE with JTAG Debugging)

How to JTAG debug the teensy project

demo firmware

at90audioinput

at90audiooutput

at90dualmidi

at90dualvirtualserial

at90ethernet

at90generichid

at90keyboard

at90keyboardmouse

at90keyboardmousenomulti

at90midi

at90mouse

at90virtualserial

at90masskeyboardfatfs - at90masskeyboard2gbsd - at90masskeyboardvirtualserialfatfs - at90masskeyboardvirtualserial2gbsd

at90extmem

at90readwritespisd

at90serialhello

at90softuartx

at90swuart

at90timers

at90buttons

at90blink

at90sketchbasicexample

leoaltsoftserial

leoblink

leobuttons

leohellowkeyboard

leorfrecver

leosketchbasicexample

leousbswitchtoat90

leoencchat

leowinbondflashdriver

adafruit_feather_32u4 demos

adafruit_feather_32u4_rf_leoencchat

evilmass

ATMEGA32U4 fuses

AT90USB1297 fuses

schematics (MIT LICENSE)

USB SWITCH + POWER

LEO

AT90

PCB (MIT LICENSE)

BOM