Can't get GATT write "command complete" to send

[Anonymous]

Hi All,

I've gone through the forums, youtube videos, and the 100 days of PSOC samples to figure this out, and am stuck.  I can't get the "command complete" event to send from my peripheral back to central, and don't know why.  I handle CYBLE_EVT_GATTS_WRITE_REQ, update the GATT DB, and call CyBle_GattsWriteRsp -- but the command complete event never gets sent.  I've tried variations in the order, changing the gatt parameters, adding in additional calls to CyBle_ProcessEvents, or even putting in random delays -- yet it never works.  I attached a debugger to the Cypress sample code, and literally looked at each call linearly, and made the same calls on my own -- yet the response is still not sent.

Here's the code link to an example program I made up to show what I expect to work:

https://github.com/ipeerbhai/PSoCBLETExperiments/blob/master/ReadWriteLED/ReadWriteExperiment/ReadWr...

Line 100 is where I handle the Write Request.  Any ideas on why this doesn't send back the response I expect would be welcome.  The repo should clone and build on the BLE Pioneer kit.

Thanks!

[Anonymous]

The documentation with the CyBle GattC Write command lists all of the events and response generated by it, as well as a quick summary of how they are handled. (You can see this by opening the API documentation for the BLE component, or doing a search-all for the function name).

Also, the CYBLE_EVT_GATTS_WRITE_REQ event should have documentation associated with it in the same way as I mentioned above about what parameters and values are needed/handled/should be replied.

[Anonymous]

I've already read the docs before asking.  The sample code I linked shows what should work according to everything in the docs and the Google.

Here's the code snippet I expect to work:

case CYBLE_EVT_GATTS_WRITE_REQ:
	// Get the write request event parameters
	wrReqParam = (CYBLE_GATTS_WRITE_REQ_PARAM_T*) eventParam;
	// see if the host wanted to write a new should blink flag
	if ( wrReqParam->handleValPair.attrHandle == CYBLE_LEDSTATE_ISBLINKING_CHAR_HANDLE )
	{
	g_shouldBlink = wrReqParam->handleValPair.value.val[0];
	BlinkTheLED();
	UpdateGATTDBWithLedState();
	CyBle_GattsWriteRsp(g_bleConnectionHandle); // Send a response.
	}
	break;

Attaching the debugger shows the Ble Handler getting called.  The LED updates correctly based on what's written by Cysmart.  The GATTDB state is correct, as I can read the db later. But CySmart times out on the write request with this code -- yet works correctly with the PSoC 100 days code sample, "Day003_Custom_Profile_CapSense_RGB_LED".  I'm making the same calls in the same order as the sample.  It should just work.

[Anonymous · Accepted solution]

Aha!  I figured out the error.  It was something stupid.

I can't call CyBle_GattsWriteRsp with my own generated handle.  I have to use the BLE generated handle!  The correct code must read:

CyBle_GattsWriteRsp(cyBle_connHandle);

It works now!! Yay!

[Anonymous]

Yeah, unless you have a need not to use the cypress variables, it is easier with only one possible BLE connection to leave all of the data/variables directly referenced.

Glad you found the problem though