Guide to troubleshoot pedalSHIELD.

Hi, thank you for this, it's really very useful!

These are my results, after checking that components are correctly placed and connected:

1. TC1044 gives -4.6v at pin 5 (Vout).
2. The sine wave generator works, although it sounds at a very low volume, even with the right pot at maximum.
3. The volume pedal program won't work at any position of the trimmer
4. The values of U1 are more or less the ones you provided, except pin3 which stabilizes at 0.85v and pin5 at 1.6v

The mix switch won't do anything: guitar bypasses only with the footswitch.

I really can't guess what's wrong...

Well, this is embarrassing.

The problem was I was using input and ouput jacks reversed, taking for granted that the arrangement was similar to other pedals (left input, right output). My mistake.

Sorry for the time lost.

Maybe you want to add this as a step 0 for the troubleshooting guide

I've been putting the PedaShield together over the last few days and just can't get it to work. I'm pretty sure it's my workmanship, but here's where I am.

I've gone through the troubleshooting guide step by step and have these results:

The electrolytic caps are in the correct places and orientation.

The diodes are in the correct orientation.

The IC's are in the correct sockets and oriented correctly.

I've looked at the back of the board for shorts and didn't see anything obvious. The top of the board looks like the pictures but the back is rougher than the pictures. I had a lot of trouble with the 8-pin connectors but finally got each one soldered with no solder connecting two pins.

I've tried to check the voltages with a multimeter but wasn't sure where the probes went. I've placed the black probe on the Arduino GND pin and the red probe on what I was measuring. I wasn't sure which of the eight legs of the TC 1044 to measure but found (clockwise from the upper left): 0.69 v, 4.40 v, 4.75 v, 4.92 v, 4.11 v, 4.33 v, 4.65 v, and 0.62 v.

I'm not sure what I should hear with the sine-wave generator. I hear a very low volume up and down which might sound like a sine wave with a period of 7 sec. Or it could just be static through my amp.

The "trimmer" is a mystery. Not sure what a "medium" position is or what to adjust it to. Right now the flat portion of the "knob" is parallel to the board.

Here's where I get further lost. As I measure the voltage on the digital pins, I get:

pin1: 3.25 v
pin2: 0.49 v
pin3: cycling between 0.20 and 0.33 v
pin4: 0.54 v
pin5: cycling between 0.22 and 0.27 v
pin6: cycling between 0.20 and 0.25 v
pin7: 0.46 v
pin8: There is no pin 8 There is a hole in PS board (J1) but there is nothing connecting PS to Arduino at pin8. I thought for a while I had the board turned 180 degrees but that would mean the screw holes are out of alignment. No idea how to proceed. Note that the CLEAN sketch was running on the AD.

The final note. The LED doesn't light up UNLESS I push the button on the AD to the left of the native USB port. Both the input and output jacks must have cables in them, however.

At this turn, I'm fairly certain I've mucked up the board and components somehow with my soldering technique and don't have much hope. However, any thoughts on where I took a wrong turn would be appreciated.

Could you check that test points below the TC1044 labeled as +5V and -5V give you this values? (or something like +4.75 and -4.75V)

At the +5 point I get +4.9 v, but at the -5 point I get +0.81 v

you should hear a continuous sound like a "piiiiiiiiiiiii" and you can adjust it from low tone to high pitched.

I still don't hear anything of interest. Do I adjust it with one of the potentiometers or the trimmer? The through signal (the pedal pressed) is very clean with no noise whatsoever.

With the trimmer swept it from one extreme to the other and you can easily see where is the middle point approx.

The mid-point is about where I have it.

Ok, so in general, first of all check that you have the correct power supply voltages +5V and -5V and this voltages reach the op-amps (pin4 is -5V and pin 8 is +5V).

Thanks. I went back to U1 (I now know which pins are which from the data sheet.).
The voltages are:
Pin 1 2.0 v
Pin 2 2.1 v
Pin 3 1.65 v
Pin 4 +0.82 v (I noted that this is the same as the reading for the -5v test point at the power supply)
Pin 5 2.4 v
Pin 6 2.2 v
Pin 7 3.24 v
Pin 8 +4.95 v

I suspect at this point, I have a short some where causing the -5v to read positive and at 20% of what it should be. Your help is gratefully appreciated.

Thanks for your help.

I worked on the soldering at the power supply and now have 4.95 @ the +5 and -4.56 @ -5. The sine sketch worked great and both P1 and P2 controlled the (very piercing) sound. However, once I have a guitar at the input and my amp at the output, I get nothing unless it's configured for pass through. This is very clean and clear. Once I push the button, there's nothing. I have maxed all 3 pots and have the switches in every possible configuration. Any advice?