How to get the Feather to talk on RX and TX shield pins rather than USB RX TX

GerryB

Hi. I’ve got my MQTT_simple application working but what I wanted to do was to talk to the feather by wires soldered onto the holes on the edge of the board labeled RX and TX. It currently only talks through the on-board UART-USB. I saw on the schematic that the USB RX and TX come from P0.05 and P0.06 whereas the shield RX and TX are mapped to P0.23 and P0.24 of the NRF9160 respectively. Is there just a configuration file somewhere to flip these to the desired ports?

GerryB

nevermind - found it in a file called circuitdojo_feather_nrf9160_common.dts

just had to switch them there

jaredwolff

GerryB you found the spot. I recommend though that you create a circuitdojo_feather_nrf9160ns.overlay within the boards directory in your project with the following entry:

&uart2 {
	status="okay";
	current-speed = <115200>;
	tx-pin = <23>;
	rx-pin = <24>;
};

(Assuming you’re using uart2) This will update/override the values in circuitdojo_feather_nrf9160_common.dts so you don’t need to modify the file itself. This is great for making project based device tree edits rather than editing your device tree for every project you’re using.