RadioMaster T8L Radio Controller User Manual

1. Introduction

The RadioMaster T8L is a compact RC transmitter designed for pilots seeking reliable performance in a sleek, lightweight design. It focuses on simplicity, accuracy, and portability, offering the core features of a full-size radio while preserving the trusted speed and dependability of ExpressLRS 2.4GHz. Whether you're starting out or looking for a clean, travel-friendly setup, the T8L is designed to get you airborne quickly.

Featuring a clean layout, high-precision Hall gimbals, easy trim control, and support for Web-UI configuration, the T8L is a powerful yet simple system. Its built-in USB-C charging and simulator compatibility provide added convenience for pilots who value efficiency without sacrificing capability. The T8L is the first screenless radio controller officially supported by ExpressLRS, bringing the power of ExpressLRS 2.4GHz into a compact form.

2. Safety Information

Radio-controlled models commonly contain sharp components like propellers, rotating at high RPM. When operating or maintaining the model, always use common sense and proceed with caution. Always disconnect power to the model AND remove propellers (if applicable) during the assembly or maintenance process.

Never operate the T8L radio system in the following conditions:

• In severe weather or strong windy conditions, such as rain, hail, snow, storms or electromagnetic environments.
• In limited visibility.
• In the proximity of other people, property, high-voltage power lines, public roads, vehicles or animals.
• When feeling unwell, or under the influence of drugs or alcohol.
• If the T8L radio system/model is damaged or showing signs of interference.
• In areas with high 2.4GHz interference or where 2.4GHz radios are prohibited.
• When the TX/RX battery is low.
• In areas where local regulations prohibit the use of R/C aircraft.

3. Getting Started

3.1. Batteries & Charging

The T8L is powered by (2x) 3.7V 18650 Lithium-ion cells and is charged using the built-in USB-C port. The charging circuitry is designed for charging (2x) 3.7V Lithium-Ion batteries only. The nominal voltage is 3.7V and the maximum charging voltage is 4.2V.

DO NOT charge 3.6V LiFe and 3.6V 18650 Lithium Ion packs with the onboard charger. Charging or using the wrong battery chemistry/polarity may cause permanent damage to the PCB and in certain situations cause fires.

Please check the voltage and condition of the battery regularly and never charge unattended. Always charge in a safe area away from combustible materials. Refrain from charging if the remote control gets wet or damaged in any way. DO NOT charge with the polarity reversed.

RadioMaster does not assume any responsibility for any adverse consequences caused by the use or misuse of this product.

3.2. Power On & Off

Power-On:

• Long-press the Power Button.
• The System LEDs will light up in a progress bar style.
• Release after a single beep.
• Two quick beeps confirm system initialization.
• Tip: Always ensure the throttle stick is in the lowest position when powering on.

Power-Off:

• Long-press the Power Button.
• The System LEDs will show a reverse progress bar.
• Release when the beep sounds.

4. Web-Based Configuration (VCP Mode)

The T8L Web UI enables configuration of settings through a computer interface, similar to the ExpressLRS Configurator. This powerful HTML-based Web UI lets you configure every major function directly from your browser.

4.1. Enter VCP Mode:

• Press and hold the Multi Function (M) button and then long-press the Power button.
• This mode is used to access USB Web Config mode (VCP).
• Note: Simulator mode is not available in VCP mode.

4.2. Connect to Your Computer:

• Use a USB Type-C cable to connect the T8L to your PC or Mac.

4.3. Open the Web UI:

• Launch a Chromium-based browser (e.g., Google Chrome or Microsoft Edge).
• Navigate to the T8L Web UI: https://radiomaster-rc.github.io/RM-Web-Page/Connection.html

4.4. Establish Serial Connection:

• Select RadioMaster T8L from the port dropdown list.
• Set baud rate (range: 9600-921600 bps, default: 115200 bps).
• Click Connect.
• Note: Ensure a stable USB connection and correct port selection to avoid connection issues.

Through the Web UI, you can:

• Calibrate sticks and trims.
• Adjust the ExpressLRS settings and power output.
• Customize endpoint ranges and reverse directions.
• Remap channels and set operation modes (Mode 1 / Mode 2).
• Customize switch behavior (click, single, double).
• Adjust audio prompts and update firmware.
• Update both the T8L and its built-in ELRS module.

5. Binding (without Web-UI)

• Power on the T8L (two beeps indicate ELRS module readiness).
• Power the receiver on/off three times to enter binding mode (the LED will flash).
• Press and hold the multi-function (M) Button for ~1 second.
• A beep confirms the command.
• The 4 system LEDs flash twice slowly to confirm the binding signal has been sent.

Troubleshooting Binding:

If the receiver displays rapid or double flashes without binding, it may require a firmware update. Visit the official ExpressLRS website to update the receiver.

Note: This is a one-way bind signal. The Rx will transition from a flashing LED to a solid ON state to confirm binding.

6. Trim Function

Trim adjustments are only available after power-on. Trim allows for fine-tuning of the gimbal centering.

When active:

• Trim LED lights up.
• The buzzer gives a rising tone.

Resetting Trim on the T8L:

• Press and hold the Trim button until a beep sounds.
• Release to complete trim reset.
• Trim LED will turn off.

7. LED Indicators

• System LEDs (x4): Show power, battery level (25% per LED), calibration, and binding status.
• Trim LED: Located behind the translucent trim button, it indicates trim activity or calibration.

8. Specifications

9. Package Contents

The package includes the following items:

• 1 * T8L Radio Controller
• 1 * USB-C Cable
• 4 * Low Tension Gimbal Springs
• 1 * User Manual (Quick Start Guide)

10. User Tips

• Simulator Use: The T8L is highly compatible with simulators, making it an excellent choice for beginners to practice FPV flying. Connect via USB-C to your computer.
• Gimbal Smoothness: If you experience unclear friction or lack of smoothness in the throttle stick, inspect the gimbal for any potential friction points against the body. Adjusting the clamp-release mechanism with a screw may help, but further investigation might be needed if the issue persists.
• Battery Insertion: Be cautious when inserting 18650 batteries, as they can fit very tightly. Avoid applying excessive force to prevent damage to the batteries or the controller.

11. Firmware Updates

The T8L is pre-installed with custom firmware. To download the latest software manual, please visit the RadioMaster website: www.radiomasterrs.com.

Firmware updates for both the T8L and its built-in ELRS module can also be performed via the Web UI configuration tool.

12. Warranty & Support

If there is any problem with your remote control hardware, please keep the proof of purchase and contact the retailer where you purchased the product.

You may also visit our warranty support page: www.radiomasterrc.com/contact.

13. Compliance

13.1. Disclaimer

⚠️ For recreation use only. Illegal modification of drones/planes is prohibited. Please also pay attention to the relevant laws and regulations on the use of drones/planes in your country/area to ensure legal use.

13.2. EU Simple Declaration of Conformity

RadioMaster declares the radio equipment T8L is in compliance with EU directives Directive 2014/53/EU.

Manufacturer by: ShenZhen RadioMaster Co., Ltd, 3F Yang Tian Building, Area 72 Xing Dang community, Xin An Street, Bao An district, Shen Zhen City, Guangdong Province, China.

Full text of the declaration of conformity is available at: www.radiomasterrc.com.

13.3. FCC Information

This equipment has been tested and found to comply with the limits for Part 15 of the FCC rules. This device complies with part 15 of the FCC rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.

When operating your RadioMaster transmitter, please be sure to maintain a separation distance of at least 20 cm between your body (excluding fingers, hands, wrists, ankles and feet) and the antenna to meet RF exposure safety requirements as determined by FCC regulations.