VOXL FPV Racing 4-in-1 ESC Datasheet

Hardware Overview

This M0138-1 high-performance ESC uses 100A 40V MOSFETs and board layout optimized for demanding FPV racing applications. The ESC supports 100A burst current per channel and over 300A total burst current (usually limited by battery and connectors). Communicate reliably with low-latency digital UART from your flight controller to the 4-in-1 ESC.

This ESC has a dedicated 5V regulated power output to power VOXL 2 or Flight Core v2 with battery voltage and current monitoring support in PX4. Additionally the ESC can power a video transmitter and has the ability to toggle on and off.

Dimensions

M0138 VOXL Racing 4-in-1 ESC 3D CAD

Board dimensions: 45.5mm x 59.0mm
Mounting hole pattern: 30.5mm x 30.5mm, M3 (3.05mm)

Specifications

Feature	Details
Power Input	2-6S Lipo (6-26V)

VOXL Power Output	5V @ 6A
VTX Power Output	16.8V @ 500mA (switch on/off). Passthrough if Vbatt < 16.8
AUX Power Output	3.3V / 5.0V @ 500mA (switch on/off, voltage selectable in software)
Payload Connector	Battery Voltage, JST Connector, rated 4A

Performance	40V, 100A+ Mosfets
	100A peak current per motor (<1s)
	40A continuous current per motor (with sufficient airflow, application dependent)
	Peak total board current 300A+ (<1s)

Software Features	Open-loop control (set desired % power)
	Closed-loop RPM control (set desired RPM), used in PX4 driver
	Regenerative braking
	Smooth sinusoidal spin-up
	Tone generation using motors
	Real-time RPM, temperature, voltage, current feedback via UART
Communications	Supported by VOXL 2, VOXL 2 Mini, VOXL Flight, VOXL and Flight Core
	Bi-directional UART up to 2Mbit/s (3.3VDC logic-level)

Connectors	4-pin JST GH for UART communication
	VOXL output: solder pads for 5.0V / 3.8V (depends on board variant)
	Payload connector: JST SM02B-SFHLS-TF(LF)(SN)
	VTX power output: solder pads
	AUX power output: solder pads

Hardware	MCU : STM32F051K86 @ 48Mhz, 64KB Flash
	Mosfet Driver : MP6531
	Mosfets: TBD (N-channel)
	Current Sensing : 0.25mOhm + INA186 (total current only). 200A max sensing range
	ESD Protection : Yes (on UART and PWM I/O)
	Temperature Sensing : 4x internal to MCU, 2x external (top and bottom of PCB)
	On-board Status LEDs : Yes
	Weight (no wires) : 17.9g
	Motor Connectors: N/A (solder pads)
PX4 Integration	Supported in PX4 1.12 and higher
	Available here in developer preview
Resources	Manual
	PX4 Integration User Guide

Connector Information and Pin-outs

UART Connector J1

Used for UART communication with the ESC
Connector on board : BM04B-GHS-TBT
Mating connector : GHR-04V-S
Pre-crimped wires : (Digikey) AGHGH28K152 or similar
3.3V signals (5.0V input is acceptable)

Pin >	1	2	3	4
Function >	N/C	UART RX (IN)	UART TX (OUT)	GND

Neopixel LED Support

Single Neopixel RGB LED outputs is available, up to 32 LEDs
Use test point labeled RGB in the AUX IO section of the ESC
The I/O pin is connected to ESC ID0 PB8 (3.3V levels)
VAUX output provides 3.3V output for the LED array
⚠️Solder carefully to test points and use strain relief to avoid damaging the pads
Test tools: voxl-esc-neopixel-test.py
Integration with PX4 is done via voxl_esc driver and modal_io_bridge

PWM Inputs / Outputs

Two independent PWM output pins are available, one pin per ESC channel
Use test points 0P and 3P (AUX IO section of the ESC)
PWM pin 0P is connected to ESC ID0, 3P -> ESC ID3 (3.3V levels)
⚠️Solder carefully to test points and use strain relief to avoid damaging the pads
PWM output is available in firmware in 39.18 or later
Operating mode of PWM pins
- PWM input is diabled on this ESC because only two I/O pins are available
- PWM output can be enabled by sending specific message to the ESC via UART interface
PWM output mode specifications
- 3 frequency modes (50hz, 200gz, 400hz)
- enable or disable timeout (0.5s). If timeout is enabled, PWM output will be disabled (set to low state) after 0.5s of no commands
- output range 0-2200 us with 0.05us resolution, special value of 2201us will force HIGH state (can be used as GPIO)
Test tools: voxl-esc-pwm.py
Integration with PX4 is done via voxl_esc px4 driver and modal_io_bridge . test app

GPIO

Available in ESC firmware 39.18 or later
Test tools: voxl-esc-gpio.py

Signal Name	MCU Pin	Function
VTX_VREG_ENABLE	CH0 PF0	VTX Power Control
AUX_VREG_ENABLE	CH0 PA12	AUX 3.3 / 5.0V Regulator Power Control
AUX_VREG_ADJUST	CH0 PA11	AUX 3.3 / 5.0V Regulator Voltage Select (disabled)