Write to Cypress peripheral from nRF52840 fails

RE: Write to Cypress peripheral from nRF52840 fails

Tushar_V — Thu, 20 Jan 2022 13:35:21 GMT

Hi LewisR,

i am working on cypress flash can u share your .dts file

Regards

Tushar

RE: Write to Cypress peripheral from nRF52840 fails

Hung Bui — Wed, 25 Nov 2020 09:28:21 GMT

Hi Lewis,
We need to compare the sniffer trace of the comm from the phone and the trace from the Adafruit module to really tell what caused the issue.
If you received the BLE_GATTC_EVT_WRITE_RSP with SUCCESS then I think it has something to do with the servo.
There is a possibility that you must enable CCCD or need to write in a certain sequence to make the servo work as it should.

But you mentioned "BUT for some reason the servo does not move UNLESS I disconnect the two devices and then re-connect." did you mean that after you disconnect and reconnect everything works fine even with the Adafruit ?

RE: Write to Cypress peripheral from nRF52840 fails

LewisR — Tue, 24 Nov 2020 19:29:58 GMT

Hi Hung Bui,

I am waiting for a sniffer I have ordered to arrive as currently I do not have one. It should be with me in the next day or so and I will update then.

The Cypress module (peripheral) is attached to a servo and moves in response to a characteristic value being written to. It is a production item and I know there is nothing wrong with this side of things. As proof, things happen as I expect when using the mobile apps (nRF connect, BLE Hero, CySmart etc...).

When I write to the same characteristic from my Adafruit nRF52 feather, I do indeed receive the BLE_GATTC_EVT_WRITE_RSP along with a GATT_SUCCESS. When I then check the value of the characteristic, it has indeed changed. BUT for some reason the servo does not move UNLESS I disconnect the two devices and then re-connect.

Is there anything you can think of that would cause this behaviour? It feels like a connection event is not terminating?

Thank you

Lewis

RE: Write to Cypress peripheral from nRF52840 fails

Hung Bui — Tue, 24 Nov 2020 14:00:35 GMT

HI Lewis,

Could you try to capture a sniffer trace of the communication ? You only need a NRF52 DK to use as a sniffer. With that we can see the difference when you do a write request from the nRF52840 and when you do write request from nRF Connect.

Could you explain what exactly you meant by "but will not carry out the action I expect as a result of the write." What exactly missing ? Did you receive the event BLE_GATTC_EVT_WRITE_RSP ?