avrgirl-usbtinyisp

Installation

npm install avrgirl-usbtinyisp

If you’re on Linux and you get an error about a missing libudev-dev package, you have to install the following as per node-usb: Installation.

sudo apt-get install build-essential libudev-dev

What is this?

avrgirl-usbtinyisp is a NodeJS implementation to drive USBtinyISP programmers. It facilitates the 2-way communication required to program and read supported Atmel AVR microchips.

Supported devices:

• SparkFun Pocket Programmer
• SparkFun Tiny Programmer
• Adafruit USBtinyISP Programmer
• Adafruit Trinket
• Arduino Gemma
• Adafruit Gemma v2
• other programmers that speak usbtinyisp protocol (see custom programmer section in this readme)

Current feature implementation of avrgirl-usbtinyisp:

• Enter / leave programming mode
• Read programmer/chip signatures
• Write to EEPROM and Flash memory
• Read from EEPROM and Flash memory
• Erase chip memory

What would I use this for?

Let's say you'd like to use NodeJS to flash and erase microchips. This could be an integrated circuit with an embedded AVR microchip. For example, you could flash a precompiled program to the chip with an USBtinyISP compatible programmer, such as a SparkFun Pocket Programmer.

Before you start

Providing options

avrgirl-usbtinyisp needs some input from you when instantiating. This is because we don't know which chip you would like to flash yet, and other details.

The options needed have the following signature:

var options = {
  debug: [boolean],
  chip: [object],
  programmer: [string]
};

Confused? Let's have a look at each one.

options.debug

Turn on debug logging in the console. Provides status messages when running methods.

options.programmer

Which USBtinyISP programmer is being used? String values for supported programmers defined below:

The custom programmer option is for any programmers that aren't on the list above, but still speak the usbtinyisp protocol. If you specify the programmer as custom, you'll need to also specify the vendor id and product id of the prorgammer using the vid and pid properties in your options.

Example:

var options = {
  chip: [whatever chip you’re programming],
  programmer: 'custom',
  pid: '0C9F',
  vid: '1781'
};

options.pid

The product id of the programmer. Only necessary if you are using a programmer of the custom type. See above for more.

options.vid

The vendor id of the programmer. Only necessary if you are using a programmer of the custom type. See above for more.

options.chip

Note: this property is not required if your programmer is an Arduino Gemma, Adafruit Gemma v2 , or Adafruit Trinket.

The chip property is an object that follows a strict format / signature. It specifies the configuration properties of the microchip you are using. You'll need to know and supply this configuration. You can find this from AVR Studio, the avrgirl-chips-json package, or use the AVRDUDE conf API. Pull requests to the avrgirl-chips-json repo with additional chips is most welcome.

Here is the required signature, provided as an example of the ATtiny85:

{
  "name": "ATtiny85",
  "timeout": 200,
  "stabDelay": 100,
  "cmdexeDelay": 25,
  "syncLoops": 32,
  "byteDelay": 0,
  "pollIndex": 3,
  "pollValue": 83,
  "preDelay": 1,
  "postDelay": 1,
  "pgmEnable": [172, 83, 0, 0],
  "erase": {
    "cmd": [172, 128, 0, 0],
    "delay": 45,
    "pollMethod": 1
  },
  "flash": {
    "write": [64, 76, 0],
    "read": [32, 0, 0],
    "mode": 65,
    "blockSize": 64,
    "delay": 10,
    "poll2": 255,
    "poll1": 255,
    "size": 8192,
    "pageSize": 64,
    "pages": 128,
    "addressOffset": 0
  },
  "eeprom": {
    "write": [193, 194, 0],
    "read": [160, 0, 0],
    "mode": 65,
    "blockSize": 4,
    "delay": 5,
    "poll2": 255,
    "poll1": 255,
    "size": 512,
    "pageSize": 4,
    "pages": 128,
    "addressOffset": 0
  },
  "sig": [30, 147, 11],
  "signature": {
    "size": 3,
    "startAddress": 0,
    "read": [48, 0, 0, 0]
  },
  "fuses": {
    "startAddress": 0,
    "write": {
      "low": [172, 160, 0, 0],
      "high": [172, 168, 0, 0],
      "ext": [172, 164, 0, 0]
    },
    "read": {
      "low": [80, 0, 0, 0],
      "high": [88, 8, 0, 0],
      "ext": [80, 8, 0, 0]
    }
  }
}

Example use

The following will upload a program to the flash memory of an attiny85:

const async = require('async');
const usbtinyisp = require('avrgirl-usbtinyisp');
const chips = require('avrgirl-chips-json');
 
let avrgirl = new usbtinyisp({
  debug: true,
  chip: chips.attiny85,
  programmer: 'sf-pocket-avr'
});
 
avrgirl.on('ready', function() {
  // upload a program to flash memory
  async.series([
    avrgirl.enterProgrammingMode.bind(avrgirl),
    avrgirl.writeFlash.bind(avrgirl, 'your-compiled-cpp-file.cpp.hex'),
    avrgirl.exitProgrammingMode.bind(avrgirl),
    ], (error) => {
      if(error){
        console.log('Error: ', error);
      } else {
        console.log('Chip flashed!');
      }
      avrgirl.close();
    }
  );
});

Available methods

getChipSignature

Gets the signature of the microchip.

Returns a buffer containing the signature bytes.

Usage:

avrgirl.getChipSignature(function(error, signature) {
  console.log(signature);
});

enterProgrammingMode

Enables programming mode on the microchip.

Returns a null error upon callback if successful.

avrgirl.enterProgrammingMode(function(error) {
  console.log(error);
});

exitProgrammingMode

Leaves programming mode on the microchip. Returns a null error upon callback if successful.

avrgirl.exitProgrammingMode(function(error) {
  console.log(error);
});

eraseChip

Erases both the flash and EEPROM memories on the microchip. Good practice to do before flashing any new data.

💣💣💣 Literally erases everything please be careful 💣💣💣

Returns a null error upon callback if successful.

avrgirl.eraseChip(function(error) {
  console.log(error);
});

writeFlash

Writes a buffer to the flash memory of the microchip. Provide a filepath string, and a callback, respectively.

Returns a null error upon callback if successful.

avrgirl.writeFlash('Blink.cpp.hex', function(error) {
  console.log(error);
});

writeEeprom

Writes a buffer to the eeprom memory of the microchip. Provide a filepath string, and a callback, respectively.

Returns a null error upon callback if successful.

avrgirl.writeEeprom('myEeprom.cpp.hex', function(error) {
  console.log(error);
});

readFlash

Reads a specified length of flash memory from the microchip. Takes a length integer (or hex) for the number of bytes to read, a starting address integer, and a callback as the arguments, respectively.

Returns a null error and a buffer of the read bytes upon callback if successful.

Usage:

avrgirl.readFlash(4, 0, function(error, data) {
  console.log(data);
});

readEeprom

Reads a specified length of flash memory from the microchip. Takes a length integer (or hex) for the number of bytes to read, a starting address integer, and a callback as the arguments, respectively.

Returns a null error and a buffer of the read bytes upon callback if successful.

Usage:

avrgirl.readFlash(4, 0, function(error, data) {
  console.log(error, data);
});

open

Void. Upon instantiation, avrgirl-usbtinyisp opens a connection to the device. You shouldn't need to call this method unless you've previously closed the connection manually.

Usage:

avrgirl.open();

close

Void. Closes the connection to the USBtinyISP device.

Usage:

avrgirl.close();

spi

SPI is a shortcut to sending an instruction buffer, of which you're simply expecting an 'OK' back. Your instruction will be sent, and the callback will return a null error if an 'OK' response returned.

Returns a null error if successful.

var buffer = new Buffer([0x01, 0x00, 0x00]);
 
avrgirl.spi(buffer, function(error) {
  console.log(error);
});

Contributing

To get this running locally, please follow the steps below:

1. Fork, then clone this repository with git cd into the new clone directory
2. Run npm install
3. Check out a new git branch to do your work in
4. Commit your changes and push this new branch to your fork
5. Open a new pull request and describe your changes as best as you can