Messages

1

preenfm2 and preenfm3 / Re: Yellow OLED : high frequency solution

« on: November 01, 2017, 02:21:05 PM »

Sorry, (I am new to this conversation), if these questions don't seem relevant.

1) Does this same signal (around 14Khz) appear when the OLED is in sleep mode (blank).
2) Has anyone tried a different colour OLED (example:Blue) from the same manufacturer?

Thank you,

Todd

2

preenfm2 and preenfm3 / Re: Testing the PreenFM405 board

« on: October 05, 2017, 03:56:31 AM »

Here is the colour image

[attachment deleted by admin]

3

preenfm2 and preenfm3 / Re: Testing the PreenFM405 board

« on: October 05, 2017, 03:55:34 AM »

All Fixed!!

I had a dickens of a time figuring out why pin 33 of the 405 and pin 6 of the OC1 were shorted to VCC. it turns out yet near pin 33 (pin 30 of the STM32), there is a VCC coupled pin (pin 32 of the STM32). I coated the area with more solder flux and retouched pin 33, 34 and 32 of the 405 and then retouched pins 30, 31, 32 on the STM32, and the short is now gone.

This synth works great, and is a ton of fun.

Attached are images of the PreenFM2 405 board and the area in question. The were shot with a cheap-assed camera microscope. The colour image is the entire board.

4

preenfm2 and preenfm3 / Testing the PreenFM405 board

« on: October 04, 2017, 06:40:56 PM »

Hi There,

I built my own Preen and Preen405 PCBs up, soldering all of the components including the SMT stuff. The STM32F4 was stupidly hard, you really need better than 10x magnification to do this properly. I don't and my vision even with a 6x magnifier is bad. Anyway, firmware loaded like a breeze... Everything works perfectly, except the MIDI RX. It connects to Ableton on USB, all the controls, menu, sounds work perfectly. Except the MIDI. I triple checked the wiring, Opto-isolator, diodes  everything. There is signal going through the opto-isolator, and to the pins on the 405, but it looks like pin 5 (according to the schematic) is where the RX signal hits the STM32.

I do not have probes that are small enough to test this pin, but does anyone know if there is a tool I can use with the ST-Link that can test all connected pins?

Sort of an in-place testing software.

Thank you.