I have two new Automation pHats and a new Pi 3 B v1.2 Neither pHat works properly with the sample “read inputs” program when plugged in bare with no wires or other equipment attached. The pHat is detected but the _update deamon throws an IOError and dies. When I check the voltages on the pHat (header and outputs) the 3.3V is nominal but the 5V is less than 0.5V. With no pHat connected both 3.3V and 5V are nominal at the header. I’m using a 2.5A “official” supply and the Pi 3 shows no other operational problems.
What quiescent current should the pHat draw on 3.3V and 5V lines?
OK, I guess. It was the first thing I checked. Also, when the first board didn’t work, I redid all the soldering. When the second board failed with exactly the same symptoms, that seemed to reject the idea that I had made a bad joint on a pHat. Unfortunately I don’t have another B version Pi to check that the problem isn’t on the Pi board (as in, soldering of the header pins, for example).
Ok, I had to ask. ;) Especially for pHats that come with the header not soldered on. Everything except the Zero comes with the GPIO header pre soldered. I wouldn’t suspect an issue that way, unless you see an obvious solder bridge. It could be the Pi, but a soldering issue is , IMHO, unlikely. It could be that the first automation pHat has a fault that did something to the Pi? Just guessing really though. Do you have another different pHat or Hat to try on that Pi? Any Pi with a 40 pin GPIO can be used to test those pHats. A+, B+, Zero etc.
Unfortunately I have no other Hats or pHats or Pi + models (I wrote B version before, by mistake). Hopefully, someone will know what the quiescent supply currents of this pHat should be and I can check that.