Awesome

Teensy FX

A Teensy 4 based FX unit with Pocket Operator style and playability.
12 knobs, 4 buttons each with LED, and 4 LEDs showing automation cycle.
Combination of filtered reverb, ping pong filtered delay and a noise source, but this is customisable.
Each knob can be automated (a bit like punch in effects on the Pocket Operators)
Tap tempo and PO sync
video series on development and use of the teensy-fx

board

Buy the right parts through the links on the kitspace page.

Based off the teensy 4 audio board and the teensy beats shield

check the git repo out to the hash to make sure everything is in sync.

Do not place C16
Swap LRCLK & BCLK - see pic lrclk-bclk-swap
2.2uF ceramics sound as good and are much cheaper than the 1uF acrylics for C8, C9, C14 & C15

test points for mic input
separate regulator for pot 3.3v to reduce noise?
put leds and buttons below pots for easier viewing and pressing
leave space on back for rubber feet
update FP of audio sockets to new FP - audio sockets weren't available in EU, changed to 35RASMT2BHNTRX which has 5 pads but will fit on the same fp
filter behind pot mux was a mistake. filters must be in front of mux or removed - fixed by removing
fix LRCLK & BCLK mixup - fixed

each knob controls one of the parameters
each knob has a number of steps of recordable automation
knob's leds brightness shows current value of parameter
record time is based on bpm tap tempo and number of steps (4 bars in control.py)
buttons are: tap tempo/sync, write, erase and start automation loop from beginning
press & hold tempo button to switch between tap tempo and PO sync mode
press write and move a knob to record its movement
moving a knob without pressing record will wipe the pattern and set it all to the current knob value
4 leds on top right show progression through the automation loop

remove modemmanager
install teensy rules: https://www.pjrc.com/teensy/00-teensy.rules

sudo cp 49-teensy.rules /etc/udev/rules.d sudo udevadm control --reload-rules sudo udevadm trigger

Then:

make prog

freeverb noise issue fixed here
- to fix this you can copy the local effect_freeverb over the one in ~/.platformio
if delay is not as long as expected (should be seconds), check teensy audio lib is up to date, older versions didn't support teensy4's large memory

patch

control.py is a PyQT program that was developed in order to make an MVP interface that could later be translated to hardware in the form of a PCB.

gui