Ah, ok. It wasn’t clear to me that “LINK” meant an optional 0 ohm jumper.
The output of the H11L1 is already clean as it is a Schmidt trigger with a digital output, I’ve used it directly with no issue in a couple of circuits.
Given that the LED driver is buffered, you should be able to have the LED and not need the two extra inverters. If those are spare gates, you might as well use them, but if these are the only three 74HC14 inverters used, you could get rid of them all by using a PNP transistor to buffer the tell tale LED instead.
The H11L1 output is actually capable of sinking 16mA so you don’t even need to buffer the LED at all, if you don’t want to.
I’ve never used anything following the opto, regardless of model, 4n35, 6n137 or 8 and pc900. All of them drive the receiving device perfectly. I currently have one 4n35 connected to the receiving port of 3 Picos without and issues.
Hi - I was just wondering if anyone had ordered the DCO PCB? If so, how much did it cost?
I’ve never done a PCB order, but I’m imagining I’d likely have to order 5?
My brother is keen for me to build him one, and though my stripboard layout works great it involves a lot more off-board wiring and would generally take a lot longer.
Most fab houses have a minimum order of 5 copies of each board (and increments of 5). OSH Park has minimum of 3, but at a much higher price than some of the others.
I don’t know if this is relevant or has been fixed, but I tried changing the MIDI channel on a Pico to 2 and the units stopped responding to MIDI messages, seems there is a check for MIDI values between 0x80 to 0x90 in the code and this means anything over channel 1 will be ignored. So change it if need be.
Was
if (midi_serial_status >= 0x80 && midi_serial_status <= 0x90 ||
Should be
if (midi_serial_status >= 0x80 && midi_serial_status <= 0x9F ||
EDIT: Seems I noted this previously but only in my MIDI channel test code and not my main code that I’m using now.
Just for clarity, the c file on GitHub has them enabled, but the uf2 build file doesn’t by default? I uploaded the latest uf2 and have lost the detune and stacking functions too, which suggests these are all disabled now in the default uf2 build file?
The build file was lost commited on march 25 2023 which suggests it has all the latest fixes applied. Have you measured the voltages on your FM input and Detune input as Detune has been there for a long time. So I suspect you have other issues.
Possibly, however both stack and detune were working perfectly with the older build I had installed previously, which didn’t include the FM code. I had soldered the LFO to the FM input already, and it was all functional (well… not the FM as I didn’t have the newer code installed). Voltages on all three inputs fine.
The only thing I’ve changed is updating a working build to the latest uf2 file to try and enable FM, and now stack and detune aren’t working.
Do you have any resources that explain how to build a uf2 file? Or even better a simple tool that does it for you…
I’ve been trying all afternoon and am absolutely going mad… I just keep getting cmake errors relating to the pico sdk path location, I’ve tried all sorts of troubleshooting to get past it.
Glad you got it working, you might want to increase the FM value from 5 to 15 for more extreme FM options, I found it a bit tame compared to what most synths can do
