Implementing UART profile between NRF52832 (as central) and HM10 (as peripheral)

[Abhinav]

I am facing some issue, I am using HM10 ble module as peripheral and NRF52832 (Redbear NANO v2) as central device. I using SDK "nRF5_SDK_12.3.0_d7731ad" and example program "nRF5_SDK_12.3.0_d7731ad\nRF5_SDK_12.3.0_d7731ad\examples\ble_central\ble_app_uart_c". I changed UUID's according to HM10 service and char UUID here "NUS_BASE_UUID, BLE_UUID_NUS_SERVICE, BLE_UUID_NUS_TX_CHARACTERISTIC, BLE_UUID_NUS_RX_CHARACTERISTIC". When I flashed code in chip and tried to run in my serial terminal I am getting

"Uart_c Scan started\n Connecting to target b5c81319fdc8\n Connected to target Starting discovery of service with UUID 0xffe0 for Connection handle 0\n

Uart_c Scan started\n Connecting to target b5c81319fdc8\n Connected to target Starting discovery of service with UUID 0xffe0 for Connection handle 0\n

Uart_c Scan started\n Connecting to target b5c81319fdc8\n Connected to target Starting discovery of service with UUID 0xffe0 for Connection handle 0"\n

and so on.......... in a continues loop

Why this is not stopping after it finding peripheral and not moving for TX RX communication.

-Is this code is only designed for to connect only with NRF5832 chips? -Can I connect to any generic BLE peripheral device using "ble_app_uart_c" example?

Waiting for reply soon

Thanks in Advance.

[Petter Myhre]

The ble_app_uart_c example implements the Nordic UART service client. It is a GAP central.

The application scans peripheral devices and connects to a device that advertises with the NUS UUID in its advertisement report. After connecting, the application enables notifications on the device that delivers the Nordic UART Service.

This code is designed to work peripherals that implements the Nordic UART service server. It doesn't work with all possible services.

What code are you running on the HM10?

[Abhinav]

Thanks for reply.

I don't have access to HM10's code but it is running uart profile. That is pre compiled BLE 4.0 module using its RX-TX we can communicate.

Is there any way to use this (ble_app_uart_c example) code to communicate with different vendor modules which implement uart profile.

[Petter Myhre]

Ok. You can probably use ble_app_uart_c as a starting point, but I have no idea of the behavior of the program on the HM10. I would use something like nRF Connect (and even better a sniffer) to look for any differences between the HM10 code, and the ble_app_uart example. The code on the HM10 is probably using a different UUID at least. I dont' really know.

[Abhinav]

Thanks for suggestion

I have already detected its (HM10) UUID and edited the code (ble_app_uart_c), while scanning code able to found HM10 and tries to connect but after connection immediately it drops the connection and again started scanning, this continues in infinite loop.

[Petter Myhre]

After connecting the next step is service discovery. I'm not sure why the connection is dropped, probably it could be because the peer disconnects, because of reset when APP_ERROR_CHECK() is called with an error that is not NRF_SUCCESS (0x00000000), or because sd_ble_gap_disconnect() is called.