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  • Author Author: Jan Cumps
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PSA.. SCPI firmware for Pico Data Acquisition Board

Jan Cumps
PSA.. SCPI firmware for Pico Data Acquisition Board

The Data Acquisition Board for Pi Pico is an analogue front end for the Raspberry Pico. 
I created SCPI firmware for it. To validate  's sample code for the board. And to see if our Pico SCPI framework can be used for custom designs. 

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What's the Pico Data Acquisition Board?

See  Data Acquisition Board for Pi Pico . It is a Pico-sized board that adds two analogue inputs to a Pico. You get 2 16-bit differential ADC channels, with +-4 V input range. You talk to it (actually: to its ADC IC) via i2c.

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The board is versatile and flexible. You can use it with Python or C. Single-shot or continuously sampling. It's up to the firmware designer. And that's a segway to:

SCPI firmware for the board

We 've been working on a Pico library for SCPI instruments. To allow you to develop LabVIEW (and standards!) compatible test instruments. The library comes with an example project, The Pico SCPI labTool.

To real test for the library is, to check if you can make an application for new hardware. That's what I'm doing here.
I took the labTool firmware template, and used it as a bootstrap to build a firmware for the Data Acquisition Board for Pi Pico .

What can it do:

  • the essential: get voltage form the acquisition board's two +- 4 V inputs, 16 bits, via SCPI
  • IEEE488.2 standard USBTMC and SCPI functions
  • additionals - 3 x GPIO in, 3 X GPIO out, 2 x 12 bit ADC in (0 - 3.3 V)

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Commands:

ANAlog:HIres:INPut#?

ANAlog:HIres:INPut#:RAW?

The .uf2 ready-to-load firmware (and source code) is available on GitHub.

To see what the firmware does, check the ./pico_scpi_mod_dataacquisitionboard subfolder. In essence, it's almost identical to the example code for the board. Adapted to become a single shot test instrument.
I've prepared that code so, that it can be offered as a lib - and (soon) as a Git submodule. You could start your own PST based firmware, and "just add" this functionality, including its SCPI commands.

LabVIEW driver

The driver will be adapted to work with this firmware too.
You 'll be able to change the ID string, so that it can regognise the analog tool.
There is an new example for the board too. Available for download on GitHub, in the driver's develop branch.

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edit: see also  PSA.. SCPI firmware for Pico Data Acquisition Board as a plug-in module .

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