Custom ADS1256 circuit

May 16

In this video I show you my new custom-built circuit which is based on a ADS1256 analog-to-digital converter and an ATmega32U4 microcontroller. I’ve been working with this AD-converter for a very long time and I also published many videos on it. Finally, I felt that I gained enough knowledge to make my own board which combines a high resolution AD converter with a microcontroller. The reason I wanted to combine these two things because I wanted to have everything on the same PCB. It looks cleaner, it is more robust, it is easier to put it in an enclosure…etc.

I will show you the whole assembly and testing process. I made a few little mistakes during the assembly and also in the PCB design, but none of them were fatal.

First of all, I forgot to add a ground connection where the ground comes in at the USB connector. It is a pretty funny mistake, because I had it on my ATmeg32U4 PCB and I basically copy-pasted it for the microcontroller part of this design. Since I added the GND tab for probing the circuit, I suspect that I accidentally removed it when I added the tab. This mistake cause most of the circuit to be separated from the ground coming from the USB.

Also, I messed up the soldering to some extent and I probably fried an ATmega32U4 microcontroller. Pretty painful thing to do in these times when there’s a chip shortage. But in general, the soldering needs to be improved; my reflow hot plate seems to provide uneven heating due to the channeled structure of the ceramic plate. I will fix this.

Now, as the board works, I will write my own ADS1256 library and I will finally finish my logging software for PC. Then, this whole package will become a product and hopefully will be helpful for small labs, students, or anyone who wants to log voltage with high resolution.