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Firmata is a protocol for communicating with microcontrollers to, e.g., set digital outputs and read analog inputs from another computer. Firmata allows rather effortless access to the digital pins on a Aurdino compatible microcontroller that in turn can be used to detect button presses and control relays. In the Blocks driver repo on GitHub, there is a driver that can be used to control a Firmata-enabled microcontroller from Blocks. This article describes how to install Firmata software on a microcontroller using the Arduino IDE and how to use the Firmata Blocks driver. It is assumed that the reader is familiar with the Arduino IDE.

Note: The Firmata driver for Blocks only supports a subset of Firmata 2.6.0. More specifically, the driver supports controlling digital inputs and outputs, analog inputs and servos over a serial connection using the StandardFirmata 2.5.9 Arduino sketch. The driver has been tested to work with the Arduino Uno and Arduino Nano Every microcontrollers.

Caution, the use of Analog inputs is not always ideal as such data is reported to Blocks as continious reports in a fixed interval potentially causing a lot of network traffic. There is a for the device global samplingInterval setting in the drivers options that should be set to as a high number as possible. If we sense temeratures a vary large number could be used. The driver has a treshold (hysterisis) setting that can prevent the driver to call update on the blocks property just from natural signal noice, preventing such input consume system resources.

Adding StandardFirmata to a microcontroller using Arduino IDE

• In the Arduino IDE Library Manager, search for and install Firmata version >= 2.5.9.
• In the Arduino IDE, open the file libraries/Firmata/examples/StandardFirmata/StandardFirmata.ino. The "libraries" folder is usually located in My Documents/Arduino/ on Windows and in home/Arduino/ on Linux.
• Upload the file to the microcontroller.

Using the driver

• Make sure the driver files has been installer on the server.
• Connect the Firmata enabled device to a PIXILAB Player Spot.
• Add the serial device in the Blocks editor on the Manage page. Use the "Firmata" driver.
• Configure the device according to the instructions in the top comment in Firmata.ts driver sourcefile.