Electrical Designer: Kenny Na
Description
BLDC motor controller compatible with 3S systems. Will initially be standalone, connecting to 12V -> 5V @ 4A Buck Converter + ELRS Board externally and then later physically integrated into another board revision for an all-in-one fixed wing solution.
Depending on the cost and performance of the board, it may be integrated elsewhere.
Documentation inspired by 12S ESC.
Requirements
Should be powered by a 3S (12V) battery input.
In the context of integrating with the ELRS board, an XT60 connector should be provided, and additional PWM input from a header pin should placed.
Must use the AM32 open-source firmware for motor control. (https://am32.ca)
This uses a sinusoidal algorithm to control the BLDC. (no FOC)
Has a strict MCU compatibility list (we would preferably use a smaller ST chip)
Components
Microcontroller Selection
Compatibility with AM32
AM32 provides a list of supported microcontrollers in their GitHub repository’s README file. Additionally, there is an MCU “target compatibility list” that can be found inside of the code. These were used to guide the selection of an appropriate MCU.
Comparison Table
Microcontroller | Option 1 | Option 2 | Option 3 |
|---|---|---|---|
Name | STSPIN32F0 | STM32L431 | STM32F051 |
Price/unit | $4.34 | $5.20 | $5.59 |
Pros | Integrated MCU with STM32F031, DC-DC, LDO, and gate driver for BLDC applications. Price can’t really be compared to other options. Physical design would be very compact since gate driver is integrated. | Previous ESC design from WARG, might be overkill | |
Cons |