ESP32-C6 + AMOLED + Hall Sensor = Vernier

A digital tuning knob (VFO) for a homebrew radio transceiver. A magnetic rotary encoder senses knob rotation, and a round AMOLED touch display shows the frequency and front-panel controls.

Interactive notebook: https://observablehq.com/@drom/vernier

Built around the Waveshare ESP32-C6-Touch-AMOLED-1.43 module:

• MCU — ESP32-C6 (Wi-Fi, RISC-V)
• Display — 1.43" round AMOLED, 466×466, SH8601 / CO5300 driver (QSPI)
• Angle sensor — MT6701 magnetic rotary encoder (I2C) on the tuning shaft
• IMU — QMI8658C accelerometer/gyro
• RTC — PCF85063
• Audio — ES7210 ADC

Component datasheets live in ref/.

Two mechanical designs coexist:

• vernier-* — original layout (basic / handle / shaft-half)
• vernier-center-* — variant with a centered display (center.md)

Each .js is a parametric Replicad script; the matching .stl is its export.

panel/ explores a modular transceiver front-panel layout — screen only, screen + VFO, screen + VFO + RIT.

See sw/README.md for the full build/flash flow. Quick version:

cd sw
. ~/esp-idf/export.sh
idf.py set-target esp32c6
idf.py -p /dev/ttyACM0 flash monitor

Set flash size to 16MB in menuconfig (Serial flasher config → Flash size).

See LICENSE.