PlainDAQ - open source DAQ module for Raspberry Pi Pico


I’ve pre-launched an open source project on crowdsupply, and I thought there would be people who might be interested in it!
It’s a simple open-source DAQ module for the Raspberry Pico.

It’s a simple board with 4 analog inputs and a single analog output, hence the name PlainDAQ!, I still doubt if it’s a good name for a product. It can also output +/-5V for powering circuits that need symmetrical power supply. Optionally it comes with ESP32-MINI-1 module. ESP32 module is flashed with ESP AT firmware before shipment to make it easy for Raspberry Pi Pico to communicate with ESP32 module through AT commands.

Let me know if you have any questions or feedback.

I also share the progress on hackaday PlainDAQ-Hackaday
If you want to get notified when we start the campaign you can subscribe: CrowdSupply - PlainDAQ

Yes, what is a DAQ, and what are its typical applications?

I mean, I get that it is 4 analogue to digital converters, and one digital to analogue output. Presumably high speed and precision ones. And the Pico has machine learning/ai hardware aboard, so signal processing? Creating home voice assistants maybe?

And what does an esp32 bring to the party? Extra CPU grunt? WiFi?

It’s obviously a nice bit of kit, I’m just confused about the application? This is obviously my lack of knowledge, not yours :slightly_smiling_face:, but I bet I’m not the only person thinking ‘cool, what can I do with it?’

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I’m deeply sorry for my late response, for some reason the notification is slipped away.

Well generally speaking it’s used for measuring voltages and generating voltages, I know that answer wouldn’t satisfy anyone, let me go deeper than that. I am designing PlainDAQ to be not only a DAQ, but an affordable all around equipment. With Analog Inputs you can use it as 4 channel voltmeter or as a 4-channel oscilloscope. With 500ksample/s (that’s 500 thousands samples per second) you can view lots of dynamic signals. I am designing a GUI that’ll be used with PlainDAQ and with that you’re going to be able to view waveforms in real-time (with triggering ofc). With that you can measure signals coming from various sensors and send it to your computer or to a web application for logging and visualization (That’s where ESP comes into play). You can even use it to view I2Cand UART signals, so it can be also useful for debugging when designing hardware.

If you’re dealing with analog circuits or opamp circuits or learning about opamp circuits it’s going to be a really useful kit because you can both generate simple waveforms and view the output with the analog input. You can test every configuration, say invering, non-invering, differentiator, integrator, custom stuff. You can measure their gain, frequency response, step response etc.

It’s worth mentioning that with 12-bit resolution you can do lots of interesting things with FFT (this is mathematical conversion to see signals freqeuncy content) with that you can view the small-signals embedded in large signals that are almost invisible in the time domain. It’s also worth mentioning that the analog inputs in PlainDAQ has very low-noise so you can enjoy the ENOB(effective number of bits) of more than 11-bit.

I don’t think RP2040 has a special hardware for machine learning or neural network, but I’ll look into it.
Let me start with the basic specs:
Analog inputs:

  • 4 Channels (multiplexed), 12-bit resolution, 72 dB SNR (11.6 ENOB, 4000:1 dynamic range)*
  • 500 k Samples /s
  • ±0.5 V, ±1 V, ±2 V, ±4 V bipolar ranges

Analog Output:

  • 1 Channel, 10-bit resolution, 50 k Samples/s, ±4 V bipolar range

They are basically semi-precision and semi-high speed hardware.

What you can do with it is up to your imagination really and here is what I came up with off the top of my head:

  • As you said lots of DSP stuff can be done with the help of RP2040. Although it doesn’t have an FPU you can do lots stuff with non-floating stuff. Digital filtering is in my to-do list. Machine learning and NN are areas where I don’t have much knowledge in, but I am sure I person with proper know can implement a NN to a degree with RP2040.

  • Digital Control. You can implement a special PID loop and you can do it pretty accurately with the help of precision ADC and DAC in the board.

  • Measuring frequency response, bode plot generation. With the help both waveform generation and waveform capturing capabilities, you can measure the frequency response of a circuit and ultimately generate bode plots.

  • Inductance/Capacitance meaurement. By forming a high-pass and low-pass circuit with a simple resistor you can measure the Inductance/Capacitance of individual components. You can do this by generating a steep pulse with DAC measuring the response with analog outputs, by measuring the rise time you can infer the Inductance/Capacitance value. I’ll show this in a video :smiley:

It’s only for wireless connectivity really. People like wireless stuff :smiley:

That’s a compliment, thanks! Again I’m deeply sorry for the late response.
If you are interested in the progress you can follow me in hackaday:

Or subscribe to PlainDAQ in crowdsupply to be notified when we go live:

I’ll be releasing videos on the application of the PlainDAQs when I near launching the product on CrowdSupply.