Connectors & Communication

Connectors

Note

Telemetry protocols are the signals being sent, connectors are the physical connection. Many connectors can run multiple protocols, so be prepared to solder different connectors running the same protocol, and be careful of connectors running different protocols.

Connector Types

Name

Image

Use Case / Notes

XT30/60/90 Connectors

XT Connectors

Most common for battery systems. Three sizes based on current.

Deans T-Plug Connectors

Deans T-Plug

Popular in RC applications. Typically lower current rating than XT.

Barrel Connectors

Barrel Connectors

Most common on proprietary commercial electronics.

Anderson Powerpole Connectors

Anderson Powerpole

Universally genderless design, color coded for various outputs.

4mm Bullet Connectors

4mm Bullet Connectors

Used in power supply. Smaller profile for high-current.

MR30 Connectors (Male)

MR30 Male

Rated for higher currents. Gendered connector.

MR30 Connectors (Female)

MR30 Female

Rated for higher currents. Gendered connector.

MT60 Connectors (Male)

MT60 Male

Heavy-duty connector for high power applications.

MT60 Connectors (Female)

MT60 Female

Heavy-duty connector for high power applications.

EC3 Connectors

EC3 Connectors

Common in drone and high-performance RC. Compact design.

EC5 Connectors

EC5 Connectors

Larger version of EC3 for higher currents. Used in RC.

MMCX Connectors (Male)

MMCX Male

Miniature precision connectors for RF/antenna applications.

MMCX Connectors (Female)

MMCX Female

Miniature precision connectors for RF/antenna applications.
XT Connector Ratings

Connector

Continuous Current

Peak Current

Wire Size

XT30

15–30 A

30–60 A

16–20 AWG

XT60

40–60 A

80–120 A

10–14 AWG

XT90

70–90 A

120–200 A

8–10 AWG

Warning

Telemetry cables are not designed to handle high current. Always provide isolated power to prevent overdrawing 5v signal wires. This is especially common with PWM, UART, and I2C connections.

Communication Protocols

Communication Protocols

Name

Pinout

Voltage / Signal

Use Case / Notes

UART

TX, RX (+ GND, Power optional)

3.3V or 5V logic levels

Universal Asynchronous Receiver/Transmitter. Very common serial RX + TX communication. Ports connect in series TX → RX and RX → TX. Simple point-to-point communication.

I2C

SDA, SCL (+ GND, Power)

3.3V or 5V open-drain

Inter-Integrated Circuit. Common for short-distance communication. Two-wire bus allowing multiple devices with unique addresses. Requires pull-up resistors.

CAN Bus

CAN_H, CAN_L (+ GND, Power)

Differential voltage (~5V)

Controller Area Network. Robust vehicle bus standard for microcontroller communication. Voltage difference provides robustness against line loss and interference. Common in automotive and industrial applications.

PWM

Signal, GND (+ Power optional)

3.3V or 5V logic levels

Pulse Width Modulation. Modulation technique encoding messages into pulsing signals. Commonly used for motor control, servos, and ESC communication. Single wire data transmission.

Note

There are plenty of open source and proprietary communication protocols (SPI, RS232, RS485, etc). Industry practice considers EMI, cybersecurity, and speed concerns. These are some of the most common well-documented protocols. Generally, proprietary protocols come with proprietary connectors—try to avoid vendor lock-in when possible.