Analog Input – Initial Circuit Testing

October 2, 2013 in 8 Channel PDU by Joshua Oster-Morris

I am currently testing the analog to digital converter (ADC) I selected to use for the new analog inputs on the PDU. In the photo below I’ve got it wired up and plugged into one of my custom made project boards I use to test out ideas for the PDU. So far, so good. The ADC and custom input buffer circuitry are working well and are accurate to within 40mV from 0-21V. That is more than adequate for my purposes so it is fair to say that I am pleased thus far. It takes longer to get a value from the ADC than it does from the digital inputs but it doesn’t take too long (≈ 400uS) so if I had 8 analog inputs to read it would take less than 4mS (1/250th of a second) total which I expect is fast enough that user will not notice a delay. I am feeling like it make be possible to remove the digital inputs circuitry and replace them with dual purpose Analog and Digital Inputs for the final product. The new prototype PDU boards (with all the latest tweaks including the analog inputs) are being fabricated as we speak and they should be here in a couple weeks at most. I’m very excited to get them because one of them has a date with a project motorcycle I am building up in Arizona and it needs a fuse block badly.

As you can see, testing electronics is an untidy business. Believe it or not, I actually know whats going on here.