Debugging 4.1 board


 
B

Brent Cooley

TVWBB Member
Sigh... I knew I'd be that guy.

I finished putting together a 4.1 HM board, hooked it to the pi and booted the SD card. Power is running from the USB->pi only at this point. The ACT light on the pi do their thing, but I never get anything on the HM board - no LCD writing, no LEDs etc. The LCD "blocks" light up but there's no writing.

I inspected the solder joints and they appear in good shape. Can anyone suggest some parts of the board to start tracing voltages to see where there may be an issue?

Also, are there any "log files" written out on the pi that may help indicate some area to focus attention to?
 
Is LED 1 Lit??
Is D3 installed the correct way.
Take pictures of the front and back of the board and upload them so people can have a look.
 
you can plug the rPi into a monitor via HDMI and see if the HM code is loading... Sounds like the ATmega isn't flashed for some reason? Perhaps solder isn't flowing from bottom to top of the board on the ATMega?
 
Thanks Frank. No, none of the HM LEDs are lit. I did check each one with ~2.2v and they all work.

I'm pretty sure D3 is installed properly, according to the silkscreen. I'm uploading pictures later in this thread.

Thanks for looking!

Frank Giacinto said:
Is LED 1 Lit??
Is D3 installed the correct way.
Take pictures of the front and back of the board and upload them so people can have a look.
Click to expand...
 
RalphTrimble said:
you can plug the rPi into a monitor via HDMI and see if the HM code is loading... Sounds like the ATmega isn't flashed for some reason? Perhaps solder isn't flowing from bottom to top of the board on the ATMega?
Click to expand...

I'm going to check on the booting via HDMI shortly. What should I look for?
 
I cant really see the solder joints on the ATmega on the top side of your board in the pictures... But my first HM had a very similar rocky start like yours, and it was because the solder didn't flow to the top side of the board... I would pull the chip from the socket and resolder that socket until you see silver solder run onto the gold traces on the TOP side of the board, then install the chip and try again...
 
When you power it up via 12v only (ie: no USB power to the rPi) does anything appear to be happening?
 
SUCCESS!!

I went into the Linkmeter section of the web console. It reported that AVR connectivity was missing and had a link to reflash the firmware to the ATMega. I picked the HM 4.0 software and it immediately came to life! LCD started to work and the thermistor temp showed up.

I'm not sure how come it didn't want to flash it when I first booted with the SD card.

Thanks to everyone who took a look and offered suggestions!
 
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