The HM-20 is an upgraded version of the HM-10. The HM-20 uses TI's CC2340 chip as the master IC. Compared to HM-10, HM-20 is a Bluetooth 5.3 BLE module,it has a faster transfer rate and a larger MTU.

Specifications
Model: HM-20
Work voltage（VCC）: 3.6V to 6V
TTL logic level (TX, RX): 3.3V
Bluetooth protocol: 5.3 BLE
Chip: TI CC2340
PIN: VCC,GND,TX,RX
Support iOS: YES
Support Android 5.0 or later
Support PC or MAC: NO

Precautions:
Bluetooth 5.0 BLE module is not compatible with any Bluetooth 2.0 SPP device
The AT commands of the HM-20 module are compatible with the AT commands of the HM-10 module (except for the baud rate setting)

About Test APP
DSD TECH offers a free app that lets you quickly integrate this module into your project.
For android, Please search "DSD TECH Bluetooth" in Google Play.
For iOS Devices(iPhone) ,Please search "DSD TECH Bluetooth" in the App Store

Customer Support:
DSD TECH provides permanent technical support and 1 year product replacement service for this Bluetooth 5.3 BLE Module. All questions will be answered within 1 working day.