https://devzone.nordicsemi.com/f/nordic-q-a/27627/nrf52-uart-at-commandsHello, I have connected my PCA10040 to a SIMCOM SIM5320 WCDMA modem and I am trying to make my PCA10040 a gateway for other BLE devices to send data over a cellular network. In order to do so, I have used the peripheral ble_app_uart example anden-USTelligent Community 13Thu, 30 Nov 2017 09:22:17 GMThttps://devzone.nordicsemi.com/thread/109106?ContentTypeID=1Thu, 30 Nov 2017 09:22:17 GMT137ad170-7792-4731-bb38-c0d22fbe4515:1864572c-9baa-41ce-a592-738c3877b0b6lirank<p>Problem solved. the RX\TX were mixed.</p> <p>Thanks</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/109105?ContentTypeID=1Mon, 27 Nov 2017 16:40:47 GMT137ad170-7792-4731-bb38-c0d22fbe4515:1831ecb5-ca01-476c-9cad-0aaf7eee771eMatt<p>The uart_event_handle() that you pass to APP_UART_FIFO_INIT() in uart_ini() should be invoked (it&#39;s a callback function) when your modem sends something back to the PCA10040. Can you share your code with us here? And have you scoped the rx/tx pins to make sure the modem does respond with some OK message?</p><div style="clear:both;"></div>