ModalAI Electronic Speed Controller (ESC)
ModalAI’s Electronic Speed Controllers (ESCs) are high-performing, closed-loop speed controllers that use a digital interface (UART, i2c in future).
Brief Overview
Brushless Electronic Speed Controllers (ESCs) are devices that consist of hardware and software for controlling three-phase brushless DC (BLDC) motors. ESCs communicate with the flight controller, which instructs the ESCs how fast the motor should spin.
ModalAI’s ESCs implement the following advanced features:
- Full integration with ModalAI VOXL and Flight Core PCBs
- Bi-directional UART communication with checksum; status and fault monitoring
- Real-time status and health reporting at high update rate (100Hz+ each)
- Closed-loop RPM control for best flight performance
- LED control from flight controller via UART
Feature Comparison between ESC V1 and V2
 |  |
| Feature | ModalAI 4-in-1 V1 ESC | ModalAI 4-in-1 V2 RevA ESC |
|---|---|---|
| Input Voltage | 6.5V-12.6V (2-3S Lipo) | 5.5V-16.8V (2-4S Lipo) |
| Aux Power Output | 5.15V 6A | 2x 4.5V (adjustable) 600mA |
| Max Continuous Current Per Motor | 5A (thermally limited) | 10A+ (thermally limited) |
| Max Burst Current Per Motor | 10A | 40-50A (requires airflow and heat-spreader) |
| MCU | Atmega328P | STM32F051K86 |
| Mosfet Driver | custom (BJT-based) | MP6530 |
| Mosfets | AO4616 (N + P) | AON7528 (N) |
| Total Current Sensing | 1mOhm + LTC2946 | N/A |
| Individual Current Sensing | N/A | 4x 2mOhm + INA186 |
| Reverse Polarity Protection | Yes | No |
| ESD signal protection | No | Yes |
| Temperature Sensing | No | Yes |
| On-board Status LEDs | Yes | Yes |
| External LEDs | RGB via BJT | Neopixel LEDs |
| Secure Bootloader | Yes (AES128) | Yes (AES256) |
| PWM Switching Frequency | 20Khz (fixed) | 48, 24 Khz |
| Maximum RPM (6 pole pairs) | 17K | 50K+ |
| PWM control input | No | Yes |
| Active Freewheeling | No | Yes |
| Tone Generation | Yes | Yes |
| Closed-loop RPM Control | Yes | Yes (10Khz) |
| Number of UART ports | 1 (250 Kbit) | 2 (2Mbit+) |
| Qualcomm ESC protocol support | Yes | Yes |
| Weight without wires (g) | 13.7 | 9.5 |
| Board Dimensions (mm) | 58.0 x 40.0 | 40.5 x 40.5 |
| Mounting Hole Size, Pattern (mm) | 3.15, 35.0 x 46.5 | 3.05, 31.0 x 33.0 |