The HM-19 is an upgraded version of the HM-11. The HM-19 uses TI's CC2640R2F chip as the master IC. Compared to HM-11, HM-19 is a Bluetooth 5.0 BLE module,it has a faster transfer rate and a larger MTU. This module can be used not only for DIY project, but also for your products. Work voltage(VCC): 3.6V to 6V TTL logic level (TX, RX): 3.3V Bluetooth protocol: 5.0 BLE Chip: TI CC2640R2F The AT commands of the HM-19 module are compatible with the AT commands of the HM-11 and HM-10 module. 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 Apple Appstore WARRANTY We back this HM-19 Bluetooth 5.0 BLE module with ONE YEAR WARRANTY. If you meet any question, please contact us, we will fix your issue within 24 hours.

DSD TECH back this HM-19 Bluetooth 5.0 BLE module with ONE Year WARRANTY and lifetime technical support. If you meet any question, please contact us, we will fix your issue within 24 hours. DSD TECH offers a free app that lets you quickly integrate this module into your project.Please search "DSD TECH Bluetooth" in Google Play and the Appstore. DSD TECH 6 PIN base Board: leads to VCC, GND, TX, RX,STATE,EN. You can be very convenient to connect to your DIY project. Bluetooth 5.0 BLE Module: The main IC is CC2640R2F from TI,Compared to the Bluetooth 4.0 module, this module has a faster transfer rate and a larger MTU. Original HM-19 module, DSD TECH brand guarantees and we accept refund without any excuse.