The purpose of the BLE Serial RS232 adapter is to convert the serial data signal from AlcoMeasure into a BLE signal (Bluetooth Low Energy), which Doorkeeper (iPad) can receive.
Any BLE Serial RS232 device should work; however, ensure that your adapter is BLE and not Bluetooth 2.0, 2.1, etc.
In this guide, we are using this particular device: uConnect S2B5232I. The key settings are:
Baud rate set to 115200 (AlcoMeasure also needs to be set to 115200 to match.)
DTE (Data Terminating Equipment).
These settings can be configured via the manufacturer's software; however, using the DIP switches is much simpler.
Set DIP switch 9 to 1 (up). This enables switch configuration (as opposed to software config).
Set DIP switch 3 to 1 (up), Switches 3-2-1 as 1-0-0 sets the baud rate to 115200.
Finally, check that the adapter is in DTE mode.
Download it here: AlcoMeasure Utility Setup Tool (Windows only)
Unlock your AlcoMeasure unit to access the Processor PCB.
Connect your PC to the PCB using a USB to USB mini cable. (USB mini connection located above.)
Click Connect (top left).
Click Configuration, then click System (bottom of screen).
Click Read Config from Unit (top of screen).
Change these settings
1 - Input Mode: Command
2 - COM3 BAUD: 115200
3 - RS232 Out: Off
4 - RS232 In: COM3
Click Write Config to Unit
Connect the Serial COM3 port to the BLE RS232 adaptor using a serial cable. Then connect a USB-A to USB mini cable from USB A on the PCB to the BLE adapter. This provides power to the BLE RS232 adapter.