The search returned 3 articles:

  1. April 2021: Project: Arduino-based MIDI Soundboard - Part 1 by Tim Blythman, PCBs: SC 23101211/2, 8 shop items [print issue] [online issue]
  2. May 2021: Project: Arduino-based MIDI Soundboard – Part 2 by Tim Blythman, PCBs: SC 23101211/2, 8 shop items [print issue] [online issue]
  3. August 2021: Project: Simple Linear MIDI Keyboard by Tim Blythman, PCBs: SC 23101213, 9 shop items [print issue] [online issue]