Tessel Firmware

API documentation

• Tessel JavaScript APIs

Directory structure

• src/ -- The main firmware source, including the C bindings to the hardware
• builtin/ -- JS binding to hardware specific API calls (such as I2C, SPI, UART, GPIO)
• lpc18xx/ -- NXP drivers for the LPC1830 peripherals
• boot/ -- USB DFU bootloader
• otp/ -- Factory setup to set the board version and install the bootloader. Can be used to update or reinstall the bootloader
• erase/ -- Tool to erase the JS bundle from the bootloader if a bug makes the main firmware unusable
• cc3k_patch/ -- Tool to update the CC3000 WiFi firmware

Compiling

Dependencies

Building the firmware requires gcc-arm-embedded, gyp, and ninja.

OS X

To install quickly on a Mac with Brew:

brew tap tessel/tools
brew install gcc-arm gyp ninja

Ubuntu 14.04

All dependencies are in the Ubuntu 14.04 repositories:

sudo apt-get install git nodejs npm nodejs-legacy gcc-arm-none-eabi gyp ninja-build

Cloning the firmware repository

We'll clone the firmware repo itself into a folder called tessel/firmware. Inside your tessel folder, run:

git clone https://github.com/tessel/firmware
cd firmware
make update

Updating

To update your firmware version, you can git pull. Each time you pull a new commit of firmware, update your submodules and npm packages by running make update.

Compiling

Inside the tessel/firmware/ directory, run

make arm

This will build a binary. If you have no errors, you should have a new binary file called out/Release/tessel-firmware.bin.

Loading firmware onto Tessel

After building your firmware in the previous step, run tessel update ./out/Release/tessel-firmware.bin.

If broken firmware prevents tessel update from entering the bootloader automatically, hold the Config button while pressing and releasing the Reset button. The red and orange LEDs blink when in the bootloader mode.

Quick tip: You can build and deploy firmware in one step by running make arm-deploy.

Bootloader

The Tessel bootloader resides in the first 64k of the SPI flash chip and presents a standard USB DFU interface. It can load and execute code in either the firmware partition in flash, or in the LPC1830's internal SRAM.

To enter the bootloader, hold the Config button while resetting or powering on the board.

To run your C program in RAM, link it for address 0x10000000 beginning with an ARM vector table (linker script), and cli/dfu/tessel-dfu-tool run_ram your_image.bin