The FZ1696 has two 3way relays which can be controlled via Bluetooth 4.0. It comes in a grey plastic case and costs about 15 Dollar. A short manual and an Android App is available. With this App you can connect to the FZ1696.
Quality-wise I would say its fine for your weekend project but its far away from deployment in a professional environment. The 3 way relays are not working correctly. The default condition one of the 2 outputs should be connected to the input but it doesn’t. You need to power up the device and control the relay so that on the 2nd output electricity can float. And that is the case on both of the two relays. I am not sure if its just mine or if its normal, but its now what i was expecting.
Next Negative thing is the Bluetooth connection. It takes almost 10 seconds to connect to the device. If you disconnect you can’t reconnect as long as the device is not in connectable mode (led blinks).
How to connect:
Open the App.
After pressing the „Scan“ , a device called „JL-CTRL“ should appear.
If you get asked for a password it should be „12345678“.
Developer Documentation:
So far I could not find any documentation of the GATT Services they’ve implemented on it but I think reverse engineering should work quite good on BLE products.
Two GATT Services are available:
GATT Characteristics:
0000ffe0-0000-1000-8000-00805f9b34fb
0000ffe1-0000-1000-8000-00805f9b34fb
To control Relays use:
0000ffe1-0000-1000-8000-00805f9b34fb
-59, 4, 49, 50, 51, 52, 53, 54, 55, 56, -86 <— Relay1 ON
-59, 6, 49, 50, 51, 52, 53, 54, 55, 56, -86 <— Relay1 OFF
-59, 5, 49, 50, 51, 52, 53, 54, 55, 56, -86 <— Relay2 ON
-59, 7, 49, 50, 51, 52, 53, 54, 55, 56, -86 <— Relay2 OFF
[0] = flag
[1] = 4/6 for ON/OFF R1 – 5/7 for ON/OFF R2
[2-X] = Password (12345678)
[LAST} = flag
In HEX this would be c5-04-31-32-33-34-35-36-37-38-