Softata is an Arduino app LIKE Firmata for RPI Pico W running Arduino. It includes a .NET package so that you can write your own client in C# to remotely control Pico devices. Console and Blazor app examples included with MAUI possible later..

Soft-ata rather than firm-ata!

From the README for the GitHub repository: djaus2/Soft-ata


The Pico app runs as a TCPIP Service taking commands, running them and returning the result to the client. For setups, displays and actuators, the expected result is simply an acknowledgement “OK:” string. For sensor reads, a data string is returned with an “OK:” prefix. The SoftaLib checks and consumes the acknowledgments from the data before it is forwarded to the client app.

The RPi Pico W has two processing cores. Whilst most interactions occur via the first core, some functionality is built into the second core. Firstly, the inbuilt LED flashes under control by the second core. When the Pico app first boots and both cores are ready, it blinks at a slow rate. (4s on/4s off).

Once a connection is made, it blinks at 4x this rate. So the client app should try connecting until then. Communication between the two cores is generally from core one to core two and is done in a synchronised manner.

The second core is also used for autonomous streaming of Sensor Telemetry data over Bluetooth and to an Azure IoT Hub. Once started, it runs with periodic transmissions without further interaction until a Pause or Stop command is sent. When paused, the transmission continues after reception of a Continue command. For every transmission, there is also a quick double flash by the inbuilt LED.

Whereas Firmata is implemented from the ground up, implemented in terms of protocols with devices being added in terms of those implementations. Softata is implemented in terms of existing specific Arduino device libraries.

To add a device you include its Arduino library and then slot it into the Softata app infrastructure. That code is, in the main, polymorphic. To add for example, a sensor you copy you copy the template sensor.cpp file and implement the methods in it according to the devices library samples. You also create header code for it largely by copying an existing sensor’s header. Within the Softata app and SoftataLib code there ar then some specific hooks to add for the device. This process is documented here. See next blog posts.


The plan was to implement an Arduino app to run on a RPi Pico W placed in a Grove Shield for Pi Pico. The Pico W has onboard Arduino implemented using the earlephilhowe BSP implementation. The Grove instructure being used because of it’s simple standardised connectivity between devices and the shield at both ends. Rather than implement a general purpose interface for devices in One Wire, I2C or SPI, etc, use is made of existing Arduino libraries for Grove devices.

The intention was also to implement a class for each device type (sensor display, actuator etc) such that the class can be extended for each actual device of that type by implementing the base methods. That way, the functionality of the app for a device type needs no modification for any additions. Additional non Grove devices can be added by connecting to a Grove cable.

Ultimately the intention was to stream Telemetry from sensors to an Azure IoT Hub Communication with a host app using a client service model with the service running on the Arduino app connected to by clients running on a host. This is all now functional.

A .NET library was built that communicates to the service as a mirror of the Arduino functionality. A Console app was built to fully test and demonstrate this functionality. A Blazor app to do same is under development. Similarly a .NET MAUI app is envisaged. Finally, a port of the .NET library to the Wilderness Labs Project Lab V3 device is also envisaged.***

API Documentation

The full API documentation here

Repository Docs


  • V5.00: Completion of Blazor app Tests


I wanted to use a RPI Pico W with Arduino installed controlled by .NET apps. Drilling deeper, I wanted to make the Pico coding available with a Blockly style UI as per CodeCraft. There is also BlocklyDuino.

After some consideration Firmata was considered. But this lacks a simple .NET (not UWP) interface.


Firmata is a protocol for communicating with microcontrollers from software on a host computer. The protocol can be implemented in firmware on any microcontroller architecture as well as software on any host computer software package. From

So if there a Firmata app running on a device, a host computrer can interact directly with the device’s hardware through a standard protocol over Serial, Ethernet (Wired or WiFi) or Bluetooth. The Firmata protocol can be viewed in the first link below. There are various implementations of it for various devices: … There is more discussion of Firmata in the Blog post. …

I could get the ConfigurableFirmata running on a RPi Pico W over WiFi. The.NET client libraries were quite old and used a Serial connection. Using a .NET Tcpip Client, I found that the functionality I could get working with interactively was limited. So I decided to build my own “Firmata”, hence Soft-ata.

Soft-ata Projects

  • Softata: The Arduino RPI Pico app
  • SoftataLib: The. NET Library
  • SoftataConsole: A simple .NET Console demo app
  • BlazorSoftata: Blazor Web Server App, some tests as Console app.

RPi Pico W Arduino

This requires a setup as per previous repositories here as well as in some blog posts:

Required Arduino Libraries


See the Console app but the IpAddress as determined when the Pico W runs must match that in the library. The ports must also match. The Console test app has multiple options:

  • 1 Digital
  • 2 Analog
  • 3 PWM
  • 4 Servo
  • 5 Sensors
  • 6 Displays
  • 7 Serial
  • 8 PotLightSoundAnalog
  • 9 UltrasonicRange
  • 10 PotRelay
  • 11 PotServo

The Blazor app has similar functionality.


  • Add more devices: Please submit.
  • Azure IoT C2D commands (Control actuators etc)
  • Please leave suggestions in teh repository Issues or Discussions,thx
  • More: See the Blog post

Enjoy! :)

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