_       __                 __                __ 
| |     / /___ __   _____  / /_  ____  ____  / /_
| | /| / / __ `/ | / / _ \/ __ \/ __ \/ __ \/ __/
| |/ |/ / /_/ /| |/ /  __/ /_/ / /_/ / /_/ / /_
|__/|__/\__,_/ |___/\___/_.___/\____/\____/\__/

Waveboot

Waveboot is a bootloader for the ATmega328P microcontroller to allow for firmware updates over the air. It is designed to be used with amplitude-shift-keyed (ASK) radios. If there's enough interest, radio support can be expanded.

Features

• ~3KB in size
• OTA firmware updates
• Supports the ATmega328P microcontroller
• Supports the RH_ASK radio
• Resilient to corrupted flash (will not boot into the application if the flash is corrupted)
• Python-based CLI tool to program the bootloader
• Depending on the radio, a device can be programmed from as far away as 100 meters

Usage

You will need at least two ATmega328P microcontrollers. One will be the bootloader, and the other will relay the firmware updates from your computer to the device.

Flashing the Bootloader

To flash the bootloader onto the device, the easiest way to do this is to use the programmer tool. But if you have another spare arduino, you can use that to program the bootloader using Arduino as ISP.

Running make will compile the bootloader, and bundle it with the app_w_reset.hex, which is the example main.cpp file compiled. This will give you the full ability to remote reset and write to the device.

make flash_combined

It is important to note that Waveboto does not reset the device for you. The programmer will send a RESET command to the device, but it is ultimately up to the user to interpret this command in the application and reset the device. The example main.cpp is an example of how to do this.

Flashing the Programmer

The programmer is a simple Arduino project that can be flashed onto the device. There's several ways to do this, but the easiest way is to open the programmer folder in the Arduino IDE and upload the sketch.

Wiring Radios

Once the bootloader is flashed, you will need to wire the radios to the microcontrollers. This can be configured in the config.h file, however, I've set them up so the reciever uses PB6 and the transmitter uses PB5. I've set it to these pins because pins PB4 and PB3 are used by the Arduino as ISP. Again, you're free to change these pins in the config.h file. You'll also need to connect the transmitter and receiver to programmer, and this can be configured in the config.h in the programmer/src/config.h file (I have these set to PB4 (transmitter) and PB3 (receiver), sorry for the confusion).

CLI

To use the CLI, you'll need to install Python and the pyserial library. You can do this by running the following command:

pip install -r requirements.txt

Once you have the dependencies installed, you can run the CLI by running the following command:

python program.py

You'll be prompted to select the serial port to use. Once you've selected the port, you can communicate with the remote device by specifying a RESET code (by default RESET). Then, you can select a hex file of your choice.

The CLI will then attempt to reset the device using the specified RESET code, and then program the bootloader.

RESET codes are customizable so users can specify a specific device if you have multiple devices. This way you won't have to worry about resetting the wrong device.

TODO:

• Add support for code-encoded signals (e.g. two RDY's may clash, but if a RDY has extra data it can be used to distinguish between devices. But then this would have larger issues with ASK frequency collisions)

• Add support for external flash backup