Tessel AVR ISP

Use this library to reflash the firmware on any Tessel module which uses an ATTiny44 microcontroller. Currently this includes the Ambient and IR modules.

Usage

Configuring Custom Firmware

If you have your own firmware you wish to flash to a module, first make sure it is compiled to Intel HEX format. Next, place the .hex file in your project directory to ensure it gets uploaded to the Tessel with the script.

Finally, set the configuration parameters in the .use method as in the example script.

var avrLib = require('../');

var isp = avrLib.use(tessel.port['A'], {
  pageSize : 64, // Microcontroller memory page size in bytes. 64 bytes for the ATTiny44
  fileName : 'my-firmware.hex' // File path to your custom firmware
});

ISP Object

The following methods are implemented to assist in flashing new firmware:

# isp.startProgramming( callback(error) )
Enters the AVR device into a programmable state.

# isp.endProgramming( callback() )
Takes the device out of programming mode.

# isp.eraseChip( callback() )
Tells the device bootloader to overwrite all program memory bytes with 0xff

# isp.readSignature( callback(error, signature) )
Asks device for its device signature.

# isp.programFuses( callback(error) )
Program and verify the device's fuse bits. Currently only programs and verifies the 'low' bits. Currently only allows the hardcoded fuse bits for the ATTiny series of microcontrollers.

# isp.verifyFuses( fuses, fuseMask, callback(error) ) Verify  the device's fuse bits. No need to call this if programFuses()
has already been called.

# isp.readPagesFromHexFile( callback(error, pages) )
Will read and parse the configured firmware .hex file into memory pages of the configured length. Returns array of page buffers through callback.

# isp.flashImage( pages, callback() )
Flashes the provided array of page buffers onto the connected AVR device.

# isp.verifyImage( pages, callback(error, incorrect) )
Not yet fully supported - Read back device's program memory and verify that it matches the provided array of page buffers. Currently a very slow process. Returns number of non-matching bytes through callback.

Example

Use the file flashAmbient.js in the examples folder of this repo to reflash the firmware on the ambient module.

License

MIT or Apache 2.0, at your option