How to remotely switch a LED sign via Bluetooth Low Energy @ 0.4mA standby current.
The base is an “ON STAGE” LED sign powered by 2x AA 1.5V batteries. The connection of the LED sign has to be changed, so it matches to the following schematic by adding a HM-10 BLE module:
Connect to the HM-10 module via serial converter with 9600,8,N,1. (some configurations are 115200 baud)
Sending AT+VERS? or AT+VERR? should generate the answer HMSoft V540. If not, the firmware has to be updated.
As next the module has to be changed to be accessed by BLE:
AT+MODE1 // makes it possible to receive AT commands via BLE
AT+PWRM0 // Activates 0.4 mA unconnected, 8 mA connected
The software will send following commands:
AT+PIO20 // turn off the PIO2 GPIO, so LED will turned off
AT+PIO21 // turn on the PIO2 GPIO, so LED will turned on
You can use the iOS App provided in the Apple AppStore: https://apple.co/3mDDcEA
Find the BLE library for iOS and macOS and more at GitHub: https://github.com/schreinerman/onstage