EasyLoader (beta)

Current Product Don't Have Test Firmware

Note: pls, use PC chrome/edge browser, if can't connect, refresh the webpage.

1. Click connect button

2. After connected successfully, pick a firmware

3. Click the burn button

4. After burning successfully, Unplug the device and restart.





COM.CAT1 is an LTE CAT1 data communication module with a built-in SIM-A7680C module for LTE CAT1 in China, it supports LTE-TDD/LTE-FDD wireless communication. The module integrates SMA external antenna interface to stabilize the communication quality and signal of the device. Integrated DC 5/12V power input interface, provide more power supply options. It can be stacked with the same series of M5 stacking modules to extend the functions. In comparison with NBIoT, CAT1 has a stronger data transmission speed. The maximum downlink rate is up to 10Mbps (uplink) / 5Mbps (downlink). This module is ideal for applications that require data transmission rates (remote control/data transit, etc.).

Product Features

  • SIM-A7680C
    • Suitable for CAT1 band in China
    • LTE CAT1 module, supports LTE-TDD/LTE-FDD wireless communication standards
    • Max. downlink rate 10Mbps/max. uplink rate 5Mbps
    • UART interface/AT command control
    • Card slot specification: Nano
  • Module interface.
    • 1x DC 5/12V POWER INPUT
    • SMA antenna interface
    • Integrated dip switch in the base, support communication pin switching
  • 5x5cm specification, compatible with M5Stack stacking system
  • Development platform:


  • 1x COM.CAT1 Module
  • 1x SMA antenna


  • Remote Control/Data Acquisition
  • Cloud application of data

SIM-A7680C Module Certification



Specifications Parameters
Communication Module SIM-A7680C
Up and Down Speed Maximum Downlink Rate 10Mbps / Maximum Uplink Rate 5Mbps
Support CAT1 band LTE-TDD: B34/B38/B39/B40/B41
LTE-FDD: B1/B3/B5/B8
Communication UART 115200bps 8N1
SIM card slot specifications Nano
Input Power MBUS(5V) / DC INPUT (5V/12V)
Net Weight 28.6g
Gross Weight 78.0g
Product size 54.2 * 54.2 * 13.2mm
Packing size 165 * 60 * 36mm


  • SIM-A7680C

Adjust the UART DIP switch on the COM.CAT1 module to switch the IO pins used by TX/RX. Adjust the power input DIP switch to adjust the 5V/12V power input.

M5Core G16/G5/G15 G17/G0/G13
M5Core2 G13/G33/G15 G14/G0/G19





Q1: How do I remove the speaker floor noise when the M5Core is on or running?

Execute the following statement in Setup() of the Arduino program

Q2: How does M5Core2 stack modules?

When M5Core2 is stacked with other M5 modules, you need to remove the battery base of Core2, which does not support module stacking.

Q3: A timeout error is displayed when uploading the program to the device

Reason and solution: The power supply current of the port is insufficient, which can cause the device to not enter the download mode normally. You can try to connect a capacitor (>0.1uF) between the RST pin and the GND pin, or when uploading the program, set the G0 Short-circuit to GND, so that G0 can be set to a low level state normally

Q4: How to solve the phenomenon of automatic signal triggering of M5Core button A

Add the header file #include <driver/adc.h> and the function adc_power_acquire(); in the Arduino program

Q5: M5 device battery life

The battery life of the controller is affected by various factors such as battery capacity, operating status, and load, so there is no fixed value. Reducing the load and adopting a sleep strategy can effectively increase the battery life.

Q6: Can multiple modules with batteries be stacked at the same time?

Support multiple stacks, the total capacity of the batteries in parallel increases, and the voltage remains unchanged. However, since the discharge of each battery is not balanced during use, there is a voltage difference between the batteries, which may cause the battery to charge backwards. .(will lose part of the battery capacity)

Q7: M5 master supports WiFi connection to 5G frequency band

ESP32 module currently does not support WiFi in 5G band, only 2.4G.

Q8: The RS485 device cannot communicate normally/data is garbled. Packet loss, etc.

Confirm whether the TX/RX pin on the TTL side of the pin is correct, try to add two 120Ω terminal resistors at the beginning and end of the device line to reduce signal reflection interference

Q9: The difference between different masters and camera products

Click the link below to view the product comparison table

Q10: M5 camera image blur, how to adjust the focal length

Rotate the lens to adjust the focal length within a certain range

Q1: How to read the programmed firmware?

Use esptool to read the flash content of esp32 and export the bin file. Refer to the detailed operation

Q2: Several solutions for esp32 board download failure in Arduino IDE board management

Restart the Arduino IDE, the computer uses the mobile AP mobile network to download.

Method 3: Download the resource package provided by M5Stack for direct installation, and extract the contents to the board management path of Arduino, such as (C:\Users\Sean\AppData\Local\Arduino15\packages), https://m5stack.oss-cn-shenzhen.aliyuncs.com/resource/arduino/packages/m5stack_v2.0.0.zip
Q3: Arduino SPIFFS file upload operation

Refer to the Github link below, use arduino-esp32fs-plugin for file upload

Q4: When M5Burner burns firmware, an error pop-up window or exception occurs

Check if the COM of the corresponding device is selected and if the M5Burner is the latest version

Q5: Does the M5 master device support multi-language display (Chinese, English, Japanese, Russian, etc.)?

UIFlow users can switch the Label font to Unicode, Arduino users can use the Chinese font library provided in the M5GFX driver library

Q6: The program cannot load the SD card normally

Confirm whether the SD card format is FAT32, and no partitions exist.

Q7: How to use Bluetooth, HTTP, SD, WebServer, FreeRTOS and other features in Arduino IDE

You can refer to the following link for other ESP32 users to share the case program

Q8: How to download programs for STAMP C3U

STAMP C3U enters program download mode operation: 1. Long press the center button (G9) of STAMP C3U when the power is off. 2. Connect to the computer, after the port is successfully identified, program burning.

Q9: How STAMP C3U defines UART0 output mode

By default, USB CDC is not enabled, the serial port output started by C3U will be output through the default pins (G20, G21) of UART0. If you want to output through USB, please use the IDE to output Its USB CDC option is enabled. (Arduino users can enable it through Tools->USB CDC on Boot-Enabled. For IDF users, please refer to the ESP IDF official documentation.)

Q10: Unable to connect to UIFlow Desktop IDE

Refer to the UIFlow documentation of the corresponding device to check whether the device has entered the USB programming mode.


Q1: Consultation for after-sales problems of products

Describe the problems encountered in detail. Screenshots of the programs involved or files can be added as attachments and sent to M5Stack's official after-sales email

Q2: Code Resources, Cases, User Communication