This is my (hopefully) last iteration of the ADS1256-based DAQ board. I replaced the ATmega32U4 microcontroller with an RP2040 and made the whole board much more compact so I could fit it in a very specific metal enclosure. The RP2040 is a faster microcontroller, so it will be more reliable to deliver the data quickly or even do some processing onboard. It also has a large flash memory which allows larger code, for example, a more complex signal processing. I picked a fairly large flash (W25Q128JVSIM, 128 Mbit or 16 MB) for this board which is maybe a bit excessive. You can probably use a smaller (W25Q16JVSNIQ (16 Mbit or 2 MB) which is 3 times cheaper, but then don't forget to add a 10k resistor at R2!

Since I had to shrink the board, most of the GPIO pins are not available. However, the purpose of the circuit is to send the acquired data from the ADS1256 AD converter to the computer via USB, so there's no need for extra pins anyway. Even the enclosure I picked prohibits having more than the USB and the input pins of the ADS1256 available.

2024-05-19 UPDATE: Apparently, some people would like to access multiple GPIO pins. So I redesigned the board a bit and made it possible to access all of the GPIO pins, except the pins used for the ADS1256. I even designed a front panel (see the GPIO version) to make it easier to access all the pins. However, if you don't need any of the GPIO pins, you can go with the normal version of the front panel. Furthermore, if you don't need the GPIOs, you can neglect J11 and J12 connectors on the bottom of the PCB.

The library I published on my GitHub is perfectly compatible with the board. One just has to make sure that the SPI pins are the 2-3-4 (SCK, MOSI, MISO) pins. This is automatically the case when the code is compiled for the "Waveshare RP2040 Zero" version of the RP2040 microcontroller. But I discuss all the details in my video anyway:

If you want to get the exact same enclosure, check the link below. I designed PCB-based front and rear panels for the enclosure as well.