Trimpots versus software calibration of Peaks

Quick question: in which version of the Peaks hardware were the null voltage trimpots replaced with firmware calibration? It looks like v3.0 of the PCB files, which appeared in late 2015, but support for calibration didn’t appear in the firmware source code until about August 2016 - is that correct? Also, the firmware calibration procedure doesn’t seem to be documented anywhere (although it can be inferred from the source code).

The context is that some people have installed Dead Man’s Catch and fhave ound that the null voltage is no longer zero volts (or slightly negative) as it should be. If they have a post-trimpot version of Peaks, then that isn’t surprising, since Dead Man’s Catch doesn’t include any of the August 2016 firmware calibration code. I wasn’t aware that it had been released (maybe GitHub sent me a message about it, but if so, I must have overlooked it).

The change took place in summer 2015. The firmware change happened at that time too, but the public github repo had not been updated (the public repo is not the one I daily work with).

To enter calibration mode, power the module on with the second button pressed. The first and second knobs (third and fourth) act as coarse/fine adjustments for offset on channel 1 (channel 2).

I am getting increasingly conservative about publishing calibration procedures - the problem is that whenever people encounter something strange with a module, the very first thing they do is to try to reinstall the firmware or to do the calibration procedure - bother operations having a significant probability of making things worse.

OK, thanks. I’ll endeavour to update DMC with calibration support ASAP, and in the meantime I’ll replicate the calibration instructions on the DMC page for anyone with a v3 Peaks who want s to revert to the factory firmware.

Yeah, there seems to be a fairly widespread believe that firmware is subject to some sort of bit-rot entropy and thus needs to be freshly re-installed as soon as something doesn’t seem right.


Any more clues on how to enter SW calibration mode?
I have a DIY peaks v 3.1 and when holding button 2 when powering on nothing happens.

Are you pressing the illuminated button? You have to press the small black button.

Hmm i briefly tried all of them, but i will confess that i mainly focused on the illuminated one :slight_smile:

Will try the black button some more when i have the time, thanks!

I feel kinda stupid but i cant enter calibration mode.

Holding the second black button (or any button) when booting just toggles it to whatever mode holding that button would put it into.
How do i know when im in calibration mode? Any visual feedback to look for?

The buttons work exactly as they should in runtime.

Ive built the firmware myself from original last source on your vagrant dev machine, and the build contains the calibration related files.

Flashed it with wav file.

Will try and rebuild and reflash.

> How do i know when im in calibration mode? Any visual feedback to look for?

Yes, the 4 function LEDs are lit.

With the new official fw, having an earlier rev of DMC installed, how do I know if I can safely start trying to install the official fw? trimpots are on the back - or pcb needs to have some certain version number or date?

I am pretty certain that the official firmware will work fine will all hardware versions of Peaks. However, if you have a later, non-trimpot version, you’ll just need to go through the firmware calibration procedure, which is easy and should only take a minute or so with a multimeter or an oscilloscope (the measurements don’t need to be very precise, so just about any properly functioning multimeter will do).

The official firmware works on all versions of Peaks. The opposite would be quite strange!

I know! I was all sorts of worried that DMC on the wrong type of hardware, in some trimpot-related meltdown :smile: had prevented further calibration.

Good looking out on Discourse! If only I could merge the email I’m being sent from, Orthogonal Devices and Mutable Instruments :slight_smile:

“you’ll just need to go through the firmware calibration procedure, which is easy and should only take a minute or so with a multimeter or an oscilloscope”

Would someone mind describing this procedure in a bit more detail?

I have Peaks in calibration mode (hold down black button 2 whilst powering on) I think, but contrary to what Emilie said instead of the function lights being lit, the SPLIT and TRIG LEDs are flashing (perhaps this was a firmware change).

I have the scope attached to the DAC8552 on pins A and B, however, rotating the Pots doesn’t change the output values. Not sure what I’m doing wrong.

Is this a diy peaks? If so, did you compile the latest code?

It seems that it’s in firmware update mode, not calibration mode.

Émilie, once again I’m in awe at how responsive you are on these forums - thanks very much. Seems that I was using an old firmware which didn’t put Peaks into calibration mode. Just updated it and calibration works great.

For anyone else who gets stuck with this problem you need firmware from this commit onwards (24th Jan 2019):

Connect a multimeter to OUT 1 (or OUT 2) and rotate knobs according to procedure above. No need to check the DAC pin outs.

2 posts were split to a new topic: Peaks clone cannot be calibrated