Project fails when Teensy 4.0 and Rev D audio board are stacked.

Status
Not open for further replies.

AJL Electronics

Active member
Title is wrong, it should read Teensy 3.6 and Revision C audio board!


Very strange this one, to me...

I am building the PD0LEW RTTY decoder https://sites.google.com/view/pd0lew/projects/rtty The code is too big for the forum, which is why I didn't post it here.

I have it built on a breadboard with the modules in line and solid wire interconnects between them of maybe four inches or so. Although it appeared to be receiving data, the output was a garbled mess, no relationship to what was being fed to it, in either polarity. My idea was that maybe the clocks didn't like the wire length, so I reconnected everything closer, but left the wire lengths as they were, but not parallel with each other. I then started getting 50% decoding accuracy.

My next step was to solder headers to the Teensy and plug the audio board directly on top. All my soldering was accurate and I have inspected it with a magnifying glass to double check. With the boards so coupled, I get nothing whatever, even the tuning indicator doesn't move. That suggests to me that the audio board is not passing data to the Teensy.
All Voltages check out and I can see the clocks where they should be.

Does anyone have a simple answer please? These photos are of the original construction when I got 0% accuracy. It was late last night when I got the issues, so gave it up to think about it a bit. I have no photos of the current build but will upload them later if useful.

IMG_4405.jpg


IMG_4406.jpg
 
Last edited:
Pictures are from Teensy3.6, not T4.0
Also cannot see if Audioboard gets 3.3V

Yes, I am of course in pillock mode! I have a separate 4.0 project to convert this one to later!

The 3.3V is obtained over the top side. Look at the three way junction where the green ends up from the rotary encoder. There is a wire from 3.3V to that point and another shorter one feeding the audio board. Orange in, brown and green out.
 
Cracked it. Two faults, one was the RTTY test signal that has amplitude variations on it and the other was a faulty header socket. There was no signal being passed to the audio board on pin 13.

Your support is greatly appreciated.
 
Status
Not open for further replies.
Back
Top