Gas gauge calibration unit

Del,

I do not know about FARR still print, what is that?

There are places to submit PCB artwork, they collect a batch, then they send to China. The cost is reasonable. I am sure the artwork becomes public domain.

I can layout the PCB for through hole parts and SMT on same board, perhaps that would be the best, people would have the choice. The SMT is so small they will easily fit under the TH parts.

The other option is, someone like you that can build a nice circuit from schematic, using a standard protoboard, RS parts, and document so others can do the same.

But first, we need to test, and make sure it does what we want.

I want to do more testing. It works for me doing the right things, but need to test for doing wrong things. I have been thinking about doing a 2 minute vid for the cal and show how it works.

I would like to send it off to you for testing on your gauges. Play with cal ....

I changed the LED blink in cal mode to ON, so the blink mode is used for low tank. I have that set for 20% now.

I did not have a logic level mosfet for the gauge drive, so just using a NPN power transistor. Either will work, pin outs the same.