We use nRF9160 on our own board.
The firmware "Serial lte modem" is installed on the chip with connection to an external MCU.
Our custom board has a connection to nRF GPIO PO.00, but any attempt set / reset the value from this pin do not work.
AT#XGPIOCFG=1,0
OK
AT#XGPIO=0,0,1
OK
AT#XGPIO=0,0,0
We tested the same scenario on the nRF9160-DK evoluation board and got the same result to GPIO P0.00, when we use the AT command for change GPIO value.
At the same time, we change the value of GPIO P0.03 without any problems through the AT command and see a change in the voltage on the GPIO.AT#XGPIOCFG=1,3
OK
AT#XGPIO=2,3
OK
AT#XGPIO=2,3
OK
As far as we understand, GPIO P0.00 is used in UART1 in the "Serial lte modem" firmware, but the UART itself is disable. uart1: arduino_serial: uart@9000 {
compatible = "nordic,nrf-uarte";
reg = < 0x9000 0x1000 >;
interrupts = < 0x9 0x1 >;
status = "disabled";
label = "UART_1";
current-speed = < 0x1c200 >;
tx-pin = < 0x1 >;
rx-pin = < 0x0 >;
rx-pull-up;
rts-pin = < 0xe >;
cts-pin = < 0xf >;
cts-pull-up;
};
Why can't we use GPIO P0.00? How to correct use GPIO P0.00 in firmware?
