Ted's Cessna Knobox =================== .. raw:: html
Materials --------- - Part I (mechanical) - a friction-locked throttle knob (I used `A820 `_) - a vernier-style mixer knob (I used `A790 `_) - hardboard, 3.5mm in thickness - M3 screws x4 for securing the potentiometers to the holders - M2 screws x4 for securing the knob ends to the potentiometer sliders - (M2.5/M3 screws + nuts) x4 for securing the holders to the enclosure - you'll need to laster-cut the hardboard and 3D-print the holders/sliders - Part II (circuitry) - stmf103c8t6 board & ST-link programmer (something like https://www.ebay.com/itm/2pcs-STM32F103C8T6-ARM-STM32-Development-Board-Module-Blue-Pill-ST-Link-V2-USA/292168190439) - slide potentiometer (10K, 88mm in length, https://www.amazon.com/gp/product/B07QVQ67MV/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1) - 3 SPDT switches + 1 SPDT toggle switch - 5 resistors (15K) - micro-USB to USB type-A cable (https://www.ebay.com/itm/90-Degree-Left-Angled-Micro-USB-5pin-Male-to-USB-B-Female-Panel-Mount-Type-Cable/162358249642) - (optional) mounting jig (https://www.amazon.com/gp/product/B07BHXXR4D/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1 works very well, but you'll need to drill the holes yourself) 3D Printed Components --------------------- - Holders: ``holder.stl`` - Sliders: ``slider1.stl``, ``slider2.stl`` Enclosure --------- - Part 1: ``cessna-knobox-enclosure1.svg`` - Part 2: ``cesnna-knobox-enclosure2.svg`` Circuitry --------- - Configure the potentiometers as voltage diviers: - Connect two ends to have 3.3v difference in voltage - Connect the pivot pins to A1 and A2 of the microcontroller - Configure the switches as pull-up inputs: - Connect the middle pin of all switches to the ground (G/GND) - Parallel one side of the resistors (15K x5) to be 5V (5V pin) - Connect the other side of each resistor as shown in the diagram: - One (left/right) pin from each of three switches connects to A8, A9, A10, respectively - Pins (left & right) of the fourth switch connect to B14, B15. - Note: the lower right switch is a SPDT switch that springs to off when no pressure is applied. It could be used as flap control. .. raw:: html
Firmware -------- - (optional) To build the firmware from source, run ``./build_image.sh`` (make sure you have Rust/Cargo installed on your computer) - Or you can use a pre-built image already available at ``./cessna-knobox.bin`` - Flash the image to the microcontroller using ST-link (you can either use the tool provided officially by ST, or do it in openocd)