I'm still working on this project to get the BT devices to sync. I got an email from the engineer that is working on it and I wanted to get your take on it as to what the best solution might be. Please see his email below.
Thanks,
Don
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Hi Don,
I am writing to update the project progress.
There is a problem with the BLE. The Nordic chip needs a BLE stack (a kind of firmware) to run as a BLE application. My code runs on top of this stack. When two BLE devices talk to each other, one is master and the other one is slave. However, the stack now just allows us to program the chip as a slave when communicating with the smartphone. In order to synchronize the strobe signal among many systems, we cannot uses the BLE protocol. I am searching the solution for this problem and I'm considering some options as mentioned below:
1. The phone is master and every light system is slave. The phone is required.
The synchronization can be done only if there is a phone in the area. This phone can then play the master role.
2. The phone is master and every light system is slave. The phone is not required.
I'm putting forward this method now. Only the transmission from phone to (one) light system is BLE protocol. The communication between two (or more) light systems is our defined protocol. During the synchronization, BLE stack will be disabled and I will use the radio link directly. Thus the phone then cannot detect and connect to the light system. I can add one more button on the light system to enable the BLE stack again when configuring the light system from phone.
ps: actually, now there are 2 BLE stack:
1. Slave (official)
2. Master (beta)
3. Master and Slave (can switch between two mode): This stack is still under developing.