BLE connection establishment sometimes slow | Cypress Semiconductor
BLE connection establishment sometimes slow
I experience very unsteady connection times when establishing a connection between twi CYBLE-022001-00 modules.
One module is configured as central, the other a peripheral. The time I am talking about is the time measured between the "CYBLE_EVT_GAPC_SCAN_PROGRESS_RESULT" event at the central
and the "CYBLE_EVT_GAP_DEVICE_CONNECTED" event at the peripheral.
Normally this time is wll below 100ms. But sometimes it takes 1 second, or even two seconds until the peripheral receives the "CYBLE_EVT_GAP_DEVICE_CONNECTED" event.
For clarification I added two screenshots:
The first "BLE-Connection-Good.png" is the good case.
The second one "BLE-Connection-Bad" is an example of a bad one.
The time scale is the same (100ms/div) in both screenshots.
The channels are as follows:
Green, rising edge: central receives "CYBLE_EVT_GAPC_SCAN_PROGRESS_RESULT" event
Red, rising edge: central calls "CyBle_GapcConnectDevice()"
Yellow, rising edge: periperal receives "CYBLE_EVT_GAP_DEVICE_CONNECTED" event
Blue: current consumption of peripheral (approx. 20mA/div); when the yellow trace is high, an additional LED current of approx. 40mA flows.
Does anyone have a hint for solving this issue? I wouldn't care about a fluctuation of 100ms to 300ms. But more than 1 or 2 seconds?
Thanks in advance.
Edit: I just realized that I accidentally uploaded two identical pictures (both were the good case), fixed.