Daisy Seed/Terrarium voltages

[Bricksnbeatles]

Hey folks! I finally had a day without school stuff to get done, so I was able to get my terrarium finished up, but I’m having some problems with the voltages…

The voltages for the relevant Daisy pins:

21	.372v
38	156.9mV
39	8.97

The voltages for the TL072

1	2.49V
2	2.49V
3	2.38V
4	0V
5	2.38V
6	2.49V
7	2.49V
8	5V

I’ve checked continuity throughout the board, and there aren’t any shorts, and everything seems to connect to what it’s supposed to connect to. No use probing the circuit since the seed is pretty much the only place where the sound goes in the circuit, so probing would solve nothing. The v-reg seems to be fine, and the voltage reaching the Daisy seed seems to be correct- just not the voltage coming from the 3.3v output pins.

Any way to test the seed via usb or something like that?

 

[benny_profane]

Have you loaded anything onto it (e.g., ‘blink’)?

 

[Bricksnbeatles]

Have you loaded anything onto it (e.g., ‘blink’)?

Not yet (though there may be something loaded onto it already), but does it need anything loaded onto it for the 3.3v digital and analog outputs to function?

 

[PedalPCB]

Sure, you can remove the Seed from the Terrarium and power it via USB.

It'll function standalone.

 

[benny_profane]

Not yet (though there may be something loaded onto it already), but does it need anything loaded onto it for the 3.3v digital and analog outputs to function?

It shouldn’t. I was curious if you had connected it to anything else or if any programming had been successful.

 

[Bricksnbeatles]

It shouldn’t. I was curious if you had connected it to anything else or if any programming had been successful.

Once I get things sorted out I’ll start on the digital stuff- Just need to find a micro-usb to usb-c cable somewhere so I can connect it to my computer.

In the meantime, meet Daisy Gillespie. After it’s all working I’ll label it with Posca pens.

https://imgur.com/a/oruTyt0

 

[Bricksnbeatles]

A bit more to the mystery… I decided to check- while the power is off, to see if there was continuity where there shouldn’t be. Pins 21 and 38 both showed continuity to ground, which is obviously no good. Decided to check to see if it was the Daisy seed or the PCB that had those pins shorted to ground somewhere. Well… no continuity between ground and the socket locations for pin 21 or 38, but also no continuity (well, small enough resistance to read as a short in the continuity checker mode, but more about that below) between pin 21 or 38 to pin 20, which is the analog ground, but there is continuity between pin 40, which is the digital ground, and both pins 21 and 38. 3.1Ω between digital ground and the analog 3.3v output, and 0.3Ω between digital ground and the digital 3.3v output. That would explain it… now it’s just a matter of figuring out why.
Looking at the Daisy datasheets, I don’t see any reason why both v regs would fail(?) and nearly short to digital ground, especially when the analog vreg is completely separate from digital ground, and the analog and digital grounds only meet externally

 

[Bricksnbeatles]

Anyone else ever have this issue with a daisy seed itself having continuity where there shouldn’t be?