NEWBIE: Troubleshooting flow?

Dirk Koenig

New member
I ordered a DIY kit and recently fired up the Hakko to make messy solder joints and huff flux fumes.

I thought things went smoothly, but my pi zero w isn't seeing the HM board, despite being powered through the HM pin connectors. Powering the board with just the LCD and button shield just yields a row of black squares and no response to button input, so I'm assuming I've got something backwards or poorly connected.

I'm curious if there's a trouble flow I can follow to get to the bottom of things. The only thing I see that's odd is that in the Google photo library, the position of a resistor and diode are reversed from what is printed on the PCB, so I followed what was printed on the board.

I feel like I'm close, but just need a little push to get there. Thanks in advance for any tips anyone can provide.

Dirk
 

Dirk Koenig

New member

This post is useful, I think, so I'll check this out. I'm still not totally sure what I should be looking for in terms of 1. Working heatermeter board 2. Working LCD/buttons board 3. Viable connection to Pi.

I think that would be valuable for newcomers so we can test along the way.
 

Bryan Mayland

TVWBB Hall of Fame
Yeah the Google Photos album is a 4.3.3 board, but the assembly instructions in the wiki show the 4.3.4 which only differs in the resistor/diode change you've noted.

The LCD and buttons won't work until the microcontroller is flashed with the HeaterMeter firmware, which relies on the Pi being able to see it. There's a diagram of what voltages you should see where in the wiki:

The pins that are signal aren't going to show those signals until the board has a firmware on it, but start by verifying that the 12V, 5V, 3.3V, and GNDs are correct, starting at the power jack -> 5V regulator -> 3.3V regulator -> AVR's VCC / AVC pins. If those are good, remove power and check continuity between the same pins listed in the post you referenced. MO -> MOS, MI -> MIS, SCK -> SCK, G25 -> RST. Make sure that these all connect, and that they are also NOT connected to any adjacent pin.
 

Dirk Koenig

New member
Well, thank you for all that. I checked everything for voltage and continuity and came up looking good. As a last stab, I grabbed a spare Pi Zero W and swapped the SD card, plopped it on the Header pins and it fired right up almost instantly. I’m glad it wasn’t my soldering on the HM, but it must have been the soldering on the Pi pins, I guess, which was also, regrettably, mine...

Thanks for the support. Now on to setting up the adapt a damper....

Dirk
 

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