New 4.3/ PI Zero W build problems

DylanNC

TVWBB Member
Finally got it all together, downloaded the image flashed the card. plug it in and the green and yellow LEDs come on but nothing else happens, been sitting now for about 15 minutes. 4.3 built with the PI Zero W, any suggestions on where to start trouble shooting. I have adjusted the potentiometer, and get 1 row of black squares on the LCD screen.
 

Bryan Mayland

TVWBB Hall of Fame
Watch the LEDs on the Pi to make sure it is booting. On the Zero, the green LED will blink like crazy as the kernel loads, then blink fast (pre-init), then more slowly (services starting and initial setup), then finally go steady (usually off). The whole process will take about a minute. If the LED just blinks constantly from power on, then make sure you downloaded the proper image. I just grabbed the Snapshot for the Pi Zero W and verified it is working with my Pi Zero W.

If it does that and still doesn't do anything, then you'll need to start debugging the HeaterMeter board, starting with checking your 3.3V power at the ATmega chip:
 

DylanNC

TVWBB Member
I download the snapshot and that didn't do anything, started checking voltages, no voltage on the middle leg of the P-MOSFET, no power at BFB on the ATmega chip or along that whole line. Not sure where to go from here. I checked all the solder connections, they looked good, checked to make sure I didn't put the wrong part in the wrong location, it appears all the parts are in the correct locations.
 
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DylanNC

TVWBB Member
Anyone have any idea what I need to trouble shoot this projecct. I ordered a new board and parts yesterday, maybe this one will go together without any problems.
 

RalphTrimble

TVWBB Diamond Member
Test your power at the power supply and trace until it is no longer present. Input 12VDC, then 5VDC out of the OKI DC-DC board, then 3.3V out of the small regulator IC. Hard to tell what the issue is from what you are saying, could be bad solder joint, could be a short (solder bridge), could be a bad regulator or mistakenly installed mosfet where the 3.3V regulator goes... that is a common mistake 'cause they look exactly alike... or even a part you forgot to install... Tracing the power from the source is the best way to go, at least that is informative to others that may be able to help you here.
 

IvanTrail

New member
Was there any resolution to this? I just built the same setup and have the same issue.

I have noticed, as well, that the backlight on the LCD is off, but will light up if I touch the header pins just below the LCD on the left and if I touch some of the pins on the Pi header as well.

I don't see any LEDs on the Pi itsself and the only indication the thing might be working is the processor chip getting warm.

I am waiting on a mini hdmi adapter and a USB hub for debugging the Pi.
 

Bryan Mayland

TVWBB Hall of Fame
If you don't see any LEDs on the Pi doing anything, then the ATmega isn't going to ever do anything to drive the HeaterMeter because it relies on the Pi booting the first time to install the software on it. Any of the indicators on the HeaterMeter aren't valid until this occurs, you're just controlling the circuitry using your body's static electricity and capacitance.

You don't need an HDMI adapter to debug this. Put in your micro SD card, no HeaterMeter attached, plug in micro USB power. No LEDs? Pi is dead. Quick blinks then nothing? Possibly you're using the wrong firmware for your Pi. You don't say which Pi or which firmware image you used so I can't tell if that's correct. Get that figured out before you even bring HeaterMeter into the mix.
 

IvanTrail

New member
Sounds like thr Pi is dead. It doesn't blink at all.
As far as I can tell, it never has. Might be a DOA unit. This is my first foray into the Raspberry Pi world, so I am not familiar with them. have another on the way.

Will report back.

Also, just as a gee whiz thing, would the Banana Pi M2 Zero work for this application? The interesting part for me is the extra antenna attachment. I have doubts as to whether or not the Pi Zero W will have range enough for my physical constraints.

Thanks for your reply.
 

Bryan Mayland

TVWBB Hall of Fame
Make sure you grabbed the right image for the Pi Zero W (if that's what you've got). It should be Snapshot -> Raspberry Pi A / B / Zero / Zero W / A+ / B+. If you grabbed the other one, the Zero might blink the 2 times on power up and that's it. If it can't read the SD card at all, it won't even blink (super helpful!).


Ah dangit, I just wrote a HeaterMeter image to my FLIR camera by mistake when trying to see exactly what the LED does on the Zero when things go wrong.
 

IvanTrail

New member
Well, I have sussed out the issue.
First problem is that the SD card I was using is some how corrupt. I can write files to it and read them as well, but, if I put a simple picture file or something, it belches and the computer gets upset. So, I tried a new SD card.

That's when I figured out the original Pi Zero W was inept. Now, that may well have been my doing not fully understanding the process before I unleashed my ham handed attempt at diagnosing something I knew nothing about. Well, now, at least, I know very little which is more than nothing!

With another Pi Zero W, a different SD card, and the snapshot firmware, it boots, connects, and the pit thermocouple and two probe ports read values reasonably close to room temperature.

This was one of those cases with multiple failures which seem to compound exponentially. I hope this result helps someone in the future.

Thanks for your help Bryan.
 

Bryan Mayland

TVWBB Hall of Fame
Nicely done! Glad you were able to work it out.

I forgot to answer your question about the Banana Pi. There's a ton of those variants and the firmware is for an entirely different system so the firmwares I generate do not work on them. I like sticking with the RaspberryPi because they are globally available in a ton of places, and the Pi Foundation is a vendor who sticks with what they create for a while, where as the other brands you never know if they'll completely abandon the hardware after release and they'll disappear. They also seem to pop out new versions or variations and it isn't worth trying to keep up with considering the Raspberry are so ubiquitous and have great support.
 

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