USIS Protocol

The Universal Spectroscope Interface Specification (USIS) protocol is designed to control any astronomical spectroscope for remote operation. This protocol is proposed by Shelyak Instruments company (www.shelyak.com).

Using a standard protocol makes possible to any device with any software. It helps the developers (both hardware and software) with precise guidelines.

In this repository, you will find:

• the specification itself (USIS-specification.md),
• a Library that implements the USIS protocol for Arduino environment (can be used for Atmega or Raspberry-Pi-Pico micro-controllers). Based on the library, you can develop your own code for a new spectroscopy device.
• Some basic demo examples
• A demo .uf2 file that you can drag and drop in a Raspberry Pi Pico to get a basic USIS device (useful for development).

USIS library & demo code

The instructions below works for Windows, MacOS and Linux

If you want to compile for the Raspberry Pi Pico, with the Arduino IDE (any other IDE is possible, specially VS Code), you can follow this link: https://arduino-pico.readthedocs.io/en/latest/

Then, just copy this folder under Documents/Arduino/libaries/usis

Open the Arduino IDE (if it was opened, you will have to restart it)

Open usis example File/examples/usis/test-01

And run !

USIS demo code for Raspberry Pi Pico

To help you during development steps, we provide the above demo code test-01.ino and test-02.ino. From the Arduino IDE, you can compile and upload the code to a fresh raspberry Pi Pico micro-controller. This makes your Pico a "USIS device" in few clicks.

You can also generate an .uf2 file that you can upload directly to the Pico. Here is the procedure (standard Pico procedure) :

• Click on "Booster button" while connecting the Pico to your computer with a USB cable.
• This makes appear the Pico in your File Manager, under the name RPI-RP2, like any USB drive.
• Then, drag and drop the .uf2 file to this drive. This uploads the code to the Pico, and disconnect it from the File Manager.
• The Pico is ready to talk with your computer through the USIS protocol !

If you don't have the Arduino IDE, you can directly upload the test-01.ino.uf2 file available in this repo.

The test-01 example is very basic: the only available property is VERSION. Then if you send the message GET;VERSION;VALUE, you'll get the reply M00;VERSION;1.0.0;; (M00 is the error code saying all is OK). If you send any other dummy message (like abcd), you'll get C02;BAD REQUEST*4C in return.

Python script for USIS demo code

As an example for controlling the USIS device through Python, we propose the script 'Demo-Python-USIS.py'. This is a basic script to show a communication example through USIS protocol. It can work with the Pico code above (then in real conditions, with a real USIS device).

To use the Python code, we recommend to follow these steps:

• Create a virtual environment (Virtualenv or Conda), with Python 3.
• Install the pyserial library (pip install pyserial).
• Copy the script in your working directory.
• Run the command python Demo-Python-USIS.py.
• You'll have access to a command line system.
  • Type ? For help (or 'help command' to get more information).
  • Type 'version' to get the version of the USIS device firmware.
  • If you type any 'bad' command, you'll get an error message.
• For each command sent, you can see the Pico LED blinking.