CMT2300A Module
Technical details
| Property | Value |
|---|---|
| Name | CMT2300A |
| Frequency | 868MHz |
| Product Info and Datasheet | Link |
Description
The CMT2300A module is a 868MHz RF module. It is important to get a module which supports SPI communication. Currently only the EBYTE E49-900M20S is supported as a standalone module, or use the OpenDTU Fusion PCB instead.
The CMT2300A uses 3-Wire half duplex SPI communication. Due to this fact it currently requires a separate SPI bus. If you want to run the CMT2300A module on the same ESP32 as a NRF24L01+ module or a PCD8544 display make sure you get an ESP32 which supports 2 SPI busses (use an ESP32-S3).
Buy your hardware from a trusted source, at best from a dealer/online shop in your country where you have support and the right to return non-functional hardware. When you want to buy from Amazon, AliExpress, eBay etc., take note that there is a lot of low-quality or fake hardware offered. Read customer comments and ratings carefully!
A heavily incomplete list of shops is:
Affiliation
This list is for your convenience only, the project is not related to any of these shops.
Pictures
CMT2300a module
Pin assignment
The actual pins used to connect the CMT2300A module to the ESP32 module are configured using a Device Profile.
| Name in Device Profile | Pin Function | Description | Possible name(s) on PCB |
|---|---|---|---|
| sdio | Digital Input/Output | SPI Data Input/Output | SDIO |
| clk | Digital Input | SPI Clock | SCLK |
| cs | Digital Input | SPI register accesser | CSB |
| fcs | Digital Input | SPI FIFO accesser | FCSB |
| gpio2 | Digital Output | Interrupt pin | GPIO2 |
| gpio3 | Digital Output | Interrupt pin | GPIO3 |
| Power | Power Supply (1,8V - 3.6V) | VDD, VCC | |
| Power | Ground | VSS, GND |