Zephyr + Argon (nRF52840) + UART with interrupts

RE: Zephyr + Argon (nRF52840) + UART with interrupts

amcelroy — Tue, 11 Aug 2020 17:20:39 GMT

Ok, so I figured it out. After reading the PlatformIO docs on Zephyr, they require the prj.conf file in the Zephyr folder along with the CMakeLists.txt file. This is different than the Zephyr docs, as they request the prj.conf to be at the top level.

Secondly, any change to the prj.conf requires a Clean -> Build under PlatformIO. Not sure if this is a feature or a bug.

The final prj.cong file UART settings that work are:

CONFIG_SERIAL=y
# CONFIG_UART_CONSOLE=n
CONFIG_UART_INTERRUPT_DRIVEN=y
CONFIG_UART_ASYNC_API=y

This unlocks all the uart functions as documented by Zephyr.

The clue was that the .config file compiled by Zephyr was not matching the prj.conf settings.

Sorry for the trouble and hope this helps someone in the future.

Austin

Edit 1 - Thanks to Simon for confirming that the code worked on his end!

RE: Zephyr + Argon (nRF52840) + UART with interrupts

amcelroy — Tue, 11 Aug 2020 13:20:32 GMT

Hey Simon,

Thank you for the quick response. I've updated the .conf file to read:

#CONFIG_DEBUG_OPTIMIZATIONS=y
#CONFIG_EXCEPTION_STACK_TRACE=y
#CONFIG_DEBUG_INFO=y

#BOARD_ADAFRUIT_FEATHER_NRF52840=n

#UART Config
CONFIG_SERIAL=y
# CONFIG_UART_CONSOLE=n
# CONFIG_SERIAL_SUPPORT_ASYNC=y
# CONFIG_SERIAL_SUPPORT_INTERRUPT=y

#CONFIG_UART_ASYNC_API=y
CONFIG_UART_INTERRUPT_DRIVEN=y
#CONFIG_UART_0_INTERRUPT_DRIVEN=y
CONFIG_UART_0_NRF_UARTE=y
#CONFIG_UART_ASYNC_API=y
#CONFIG_UART_NRF=y

Then, I tried to call uart_irq_callback_set, but the compiler is still reporting, "undefined reference to `uart_irq_callback_set'".

Attached are the outputs of the "Packages" that Zephyr is using:

CONFIGURATION: https://docs.platformio.org/page/boards/nordicnrf52/particle_argon.html
PLATFORM: Nordic nRF52 4.4.0 > Particle Argon
HARDWARE: NRF52840 64MHz, 243KB RAM, 796KB Flash
DEBUG: Current (jlink) External (jlink)
PACKAGES:
 - framework-zephyr 2.20300.200623 (2.3.0)
 - framework-zephyr-canopennode 0.0.0-alpha+sha.5c6b0566d5
 - framework-zephyr-civetweb 0.0.0-alpha+sha.99129c5efc
 - framework-zephyr-cmsis 0.0.0-alpha+sha.542b2296e6
 - framework-zephyr-fatfs 0.0.0-alpha+sha.9ee6b9b951
 - framework-zephyr-hal-nordic 0.0.0-alpha+sha.742d8fb839
 - framework-zephyr-libmetal 0.0.0-alpha+sha.3c3c9ec83b
 - framework-zephyr-littlefs 0.0.0-alpha+sha.0aefdda69d
 - framework-zephyr-loramac-node 0.0.0-alpha+sha.29e516ec58
 - framework-zephyr-lvgl 0.0.0-alpha+sha.74fc2e753a
 - framework-zephyr-mbedtls 0.0.0-alpha+sha.4bf099f125
 - framework-zephyr-mcuboot 0.0.0-alpha+sha.e88113bbeb 
 - framework-zephyr-mcumgr 0.0.0-alpha+sha.5885efb7ca
 - framework-zephyr-mipi-sys-t 0.0.0-alpha+sha.957d46bc3c
 - framework-zephyr-open-amp 0.0.0-alpha+sha.724f7e2a45
 - framework-zephyr-openthread 0.0.0-alpha+sha.a83d18cf18
 - framework-zephyr-segger 0.0.0-alpha+sha.6fcf61606d
 - framework-zephyr-tinycbor 0.0.0-alpha+sha.40daca97b4
 - framework-zephyr-tinycrypt 0.0.0-alpha+sha.3e9a49d267
 - framework-zephyr-trusted-firmware-m 0.0.0-alpha+sha.7de2daa196
 - tool-cmake 3.16.4
 - tool-dtc 1.4.7
 - tool-ninja 1.9.0
 - tool-sreccat 1.164.0 (1.64)
 - toolchain-gccarmnoneeabi 1.80201.190214 (8.2.1)

RE: Zephyr + Argon (nRF52840) + UART with interrupts

Simon — Tue, 11 Aug 2020 12:54:43 GMT

I was able to make interrupt-based UART work by using uart_irq_callback_set(..) which only requires CONFIG_UART_INTERRUPT_DRIVEN to be set to y (in addition to CONFIG_SERIAL, CONFIG_UART_<instance>_NRF_UARTE). Please tell me if this is sufficient for you or if you want to use the async API, then I'll look into it.

Best regards,

Simon