recurBOY update

since the underscores soft-launch there has been a few updates to the recurBOY project:

hardware update

the recurBOY circuit depends on more harder-to-source components than others in the underscores catalog. This is because it was originally designed only to be built together in group soldering sessions – where we would source all the parts for the workshop beforehand.

Now that it is a fully open diy project (with some people sourcing the parts for themselves) I have updated the build guide with more information about selecting these parts

recurBOY uses a 1.8 inch tft display (ST7735S) in a form-factor commonly found on ebay/amazon/aliexpress – unfortunately this is not compatible with the waveshare version – who i have found to be a reliable supplier of display hardware in the past (perhaps a future hardware revision should somehow allow this version of the display to be used also ?)

a bunch of screens to test

based on some feedback from users + my own exploration of testing these displays, I found that some of them were not working on the recurBOY r0.6 pcb. However when i tested the same (faulty?) displays with pin-jumpers wired to the pi directly they would always work!?

A laborious process of trial and error discovered that in particular the SDA pin ie SPI data input between screen and rpi was the problem – soldering a floating wire to this was enough to consistently fix this issue across all the “faulty” screens i tested.

the DISPLAY_SDA trace between PIN38 on pi and PIN5 on display is the problem!

I couldnt really see any difference to the signal before and after this “fix” on the scope, but my best guess is that the trace on the pcb is a bit too weak for some screens to read it.

example of part of the SPI message on SDA pin

I updated the pcb to make this trace much bolder – bumping circuit from v0_6 to v0_7_1 (v0_7_0 fixed it also but accidentally broke a trace on the rca out – whoops) and now every screen that I have tested works

same schematic -> different pcb !

all of this could have been avoided if we had selected a more reliable part from a reputable supplier – however this could incur also a large increase in price for the project + ( potentially ) more difficulty for diy-er to source in small batches.

for as long as we design with hacky parts occasionally we will need to make hacky updates – and i stand by this decision !

open projects have the flexibility to adapt to their changing surroundings and this is a good example of that!

software update

recurBOY was designed to distill some of the best parts of a r_e_c_u_r video sampler while running on cheaper hardware (a rpi_zero) and keeping the interface simple.

one feature of r_e_c_u_r that i use often and miss with my recurBOY is processing live-video feed (eg from a camera or another video-synth)

processing live input

running input from a piCamera over csi into recurBOY proved to be too much for the pi_zero to handle. To my surprise however it could seem to handle input from a usb-video device like EasyCap capture cards

i cant guarantee it will work with any usb-video-input , but now if recurBOY detects a device on startup you will get access to a third source mode that allows you to preview that input and apply effects to it !

self-portraits w recurBOY digitial effects !

img file & other updates

you can download new image file and see the full list of changes on the v2.1.0 release page but in short, a few of the other ‘quick wins’ i also added in this release:

  • usb_midi support – including independent shaderParam and effectParam controls
  • sampler mode now plays images – jpeg/jpg, png & gif (single image only) supported
  • output sd over hdmi – defaults to 640×480 and seems to handle this without lag

please let me know if you have any issues or find bugs in this release – it has only been tested by me so far (i will keep old image up too if you need the stability)

when looking for things to update i rely on the issue tracker on github – no promises but putting your suggestions here is the best way to have them noticed!