FOCn ESP32-S3-based, medium-power BLDC driver module supports SimpleFOC

European engineer, Matej Planinšek of PLab, has developed the FOCn — a medium-power BLDC driver module based on ESP32-S3 WiSoC capable of delivering up to 10A of continuous current. It is compatible with the SimpleFOC Arduino library making it easier to control BLDC (brushless direct current) and stepper motors with the field-oriented control algorithm.

The developer was inspired to create the FOCn module when their search for a custom-made, SimpleFOC-compatible driver module that met all their requirements failed. The name is related to field-oriented control (FOC) and also means “face slap” in Slovenian, Matej’s native language.

The driver module is based on the ESP32-S3 dual-core XTensa LX7 microcontroller which provides Wi-Fi and Bluetooth connectivity. The microcontroller further supports ESP-NOW, a low-power and low-latency communication protocol, which makes it possible for multiple FOCn boards to talk to one another.

FOCn driver module specifications:

MCU – ESP32-S3 dual-core XTensa LX7 microcontroller @ 240MHz
Wireless – 802.11 b/g/n Wi-Fi, Bluetooth 5 (LE)
USB – USB Type-C for programming and debugging
Pluggable terminal block
- Input voltage – 9V to 45V (3s – 10s lithium)
- Input current – 10A constant, fuse protected
- Phase current – 10A constant, 25A peak (more possible with enhanced cooling)
- Phase current measurement range – +-38A
- PWM
  - Output current – 5A average
  - Load type – Supports inductive loads (flyback diode protection)
- Hall/encoder supply voltage – 5V
- Allowable external load on 5V supply – 300mA
- 2x auxiliary input for I2C encoders
Idle current consumption (motor driver disabled, MCU seep sleep) – <200uA
Gate driver with shunt amplifier – DRV8323
Dimensions – 85.4 x 62 mm

The USB-C port on the board can be used to program and debug the driver module. Extra cooling (heat sink or cooling fan) may be required in situations that require prolonged high motor current currents (>10A) and high ambient temperatures (>35°C).

The FOCn project is completely open-source. 3D models, schematics, Altium files, and documentation for the project are hosted on the FOCn GitHub repository, together with a PlatformIO project example. For more information about the driver module, you can refer to the earlier-mentioned repository or the project page on Hackaday. It is available for purchase on Tindie for $64.

Via Hackster

Tomisin Olujinmi

Tomisin is a writer specializing in hardware product reviews, comparisons, and explainers. He is very passionate about small form factor and single-board computers.