Cheatsheet For Installing LFOR Firmware (ST Modular PCB v1.0)
Items Needed

  • Connect the AVRISP MKII Programmer to the computer via USB cable

  • Connect a 6‑pin ribbon cable from the AVRISP MKII Programmer to the LFOR 6‑pin jack (labeled as AVR)
    • Ensure the red stripe is oriented with the line indicator (Pin 1) on the PCB as seen in the image on the right

  • Connect a 10‑pin ribbon cable from Eurorack case power to the LFOR 10‑pin power header

  • Power on the computer
    • One red LED and one green LED should now be lit on the AVRISP MKII Programmer
      • ‑or‑ One red LED and one blue LED if your AVR device is a counterfeit  😎

  • Power on the Eurorack case (this will supply power to the LFOR module)

  • Run the Atmel Studio v7.0 Program (Refer to the images below for the sequence numbers shown in RED)
    • At drop‑down menu choose "Tools" then
      •   (1) Click the "Device Programming" tab
      •   (2) Choose "AVRISP mkll" for Tool and choose "ATtiny85" as the Device
      •   (3) Choose ISP for Interface and Click the "Apply" button
      •   (4) Click the "Read" Device Signature button. Both green LED's on the AVRISP MKII Programmer should now be ON
      •   (5) Click the "Read" Target Voltage button
      •   (6) Click the "Fuses" tab
      •   (7) Change these settings
        •     EXTENDED = 0xFF
        •     HIGH = 0xDF
        •     LOW = 0XE2
        •     Place a checkmark in the "Auto read" and "Verify after programming" boxes
      •   (8) Click the "Program" button and "Verify registers ... OK" should be shown
      •   (9) Click the "Memories" tab and place checkmarks in the first two boxes
      • (10) Choose the firmware file LFOR.hex
      • (11) Click the "Program" button and the LED on the LFOR module will blink rapidly during the firmware transfer
        •     ▪ A solid red LED and a flashing green LED on the AVRISP MKII will light up
        •     ▪ "Verifying Flash...OK" should be displayed when done
      • (12) Click the "Close" button

  • Flip the toggle switch on the LFOR module all the way to the top position
    • The LED on the LFOR module will blink at the speed set by the RATE knob
    • Turn the RATE knob fully clockwise and then fully counter‑clockwise
    • If you are able to control the rate of the LED then congrats! The firmware was installed correctly

  • Power off the Eurorack case and ensure the LFOR module is off

  • Unplug the AVRISP MKII Programmer's 6‑pin ribbon cable from the LFOR PCB

  • Verify the LFOR module is working
    • Power on the Eurorack case
    • Plug a cable into the TRIANGLE OUT jack. Plug the other end into the GATE IN jack of a different module and verify a response


* Note: Everything needs to be done in the order shown above or it won't work. There are other ways to install firmware on the LFOR. The instructions shown above represent only one method. The designer of the LFOR module uses a different hardware programmer called "MySmartUSB Light AVR ISP Programmer"