Invert UART TX Signal

[Marcio Segura]

Good day, I am using a USB to UART IC and it isn't working just because the nRF51822 Tx signal is inverted from this IC. There are some way to invert the UART signals?

[Joe Merten]

Using pure-gcc, the following pure-gcc/Makefile should work with the original "simple uart" demo from the sdk:

DEVICE := NRF51
BOARD := BOARD_PCA10001
#BOARD := BOARD_NRF6310
USE_SOFTDEVICE := s110

# List of all Sourcefiles
APPLICATION_SRCS := main.c simple_uart.c

# Use shell to find name of root folder. Possible but horrible to do in make.
PROJECT_NAME := $(shell basename "$(realpath ../)")

# Some directories, which must be adjusted individually
SDK_PATH := ../../../../Nordic/nrf51_sdk_v5_2_0_39364/nrf51822/
TEMPLATE_PATH := ../../../../HaalandSetup/template/
TOOLCHAIN_PATH := /opt/gcc-arm-none-eabi-4_8-2013q4/bin/

include $(TEMPLATE_PATH)Makefile

I'm still unshure what hardware you're owning. I don't know a "PCA1000". I think there are some "Usb Sticks" which named about ""PCA10001" or "PCA10003" - but I havn't those one. I'm using a nRFgo Starterkit which consist of a nRF6310 Mainboard and a PCA10005 add on "Cpu Module Board" (like seen here).

I'd attached 4 binaries so you can perform some tests. The both "blank" are for use without SoftDevice and the both "s110" are for use with the s110 SoftDevice. The both "nRF6310", I'd tested and they are working well. Regarding the both "PCA10001", I cannot test because I have not such hardware. For all binaries, the RS232 is configured to 115.200, 8n1 without any flow control.

Good luck ;-)

Uart_nRF6310_blank.zip

Uart_nRF6310_s110.zip

Uart_PCA10001_blank.zip

Uart_PCA10001_s110.zip