Zephyr SimpleIot Application

This is a Zephyr Workspace T2 topology that sets up to build the SIOT Zephyr application.

Setup

• install Zephyr dependencies as outlined in the Getting Started Guide
• mkdir zephyr-siot
• cd zephyr-siot
• Choose mainline Zephyr or nRF SDK
  • mainline: west init -m https://github.com/simpleiot/zephyr-siot.git
  • nRF: west init -m https://github.com/simpleiot/zephyr-siot.git --mf west-nrf.yml
• west update
• cd siot
• . envsetup.sh (notice leading .)
• siot_setup

Build

• cd zephyr-siot/siot
• . envsetup.sh (notice leading .)
• siot_build_<board> src/<app>

Flashing

• siot_flash (STM32, nRF)
• siot_flash_esp <serial port> (serial port is required for ESP targets)

Open serial console

The SIOT firmware applications all have the serial shell enabled, so you can connect to that to interact with the system.

Highly recommend the tio tool.

• tio /dev/serial/by-id/...

Applications

• siot-net: Start of generic network connected SIOT app
• siot-serial: Start of generic serial connected SIOT app
• siggen: Signal generator app that uses DAC output.
• siot-nrf: An application that runs on the Nordic nRF9151 Feather module.

Memory management

Getting all the memory knobs tuned correctly in Zephyr can be a challenge. Generally, the advice is to make sure stacks never go above 70% used (kernel thread stacks).

The following config options can also be enabled to help track down memory issues:

# Stack debugging information
# TODO: may want to remove for production
CONFIG_ASSERT=y
CONFIG_ASSERT_VERBOSE=y
CONFIG_THREAD_NAME=y
CONFIG_THREAD_STACK_INFO=y
CONFIG_STACK_CANARIES=y
CONFIG_STACK_SENTINEL=y

Debugging Crashes

The west-debug-tools are integrated and can be used like:

(py) [cbrake@quark siot]$ west dbt addr2src 0x400fc9f1
Reading symbols from /scratch/simpleiot/zephyr-siot/siot/build/zephyr/zephyr.elf...
0x400fc9f1 is in uart_esp32_irq_rx_ready (/scratch/simpleiot/zephyr-siot/modules/hal/espressif/zephyr/esp32/../../components/hal/esp32/include/hal/uart_ll.h:295).
290
291	    // When using DPort to read fifo, fifo_cnt is not credible, we need to calculate the real cnt based on the fifo read and write pointer.
292	    // When using AHB to read FIFO, we can use fifo_cnt to indicate the data length in fifo.
293	    if (rx_status.wr_addr > rx_status.rd_addr) {
294	        len = rx_status.wr_addr - rx_status.rd_addr;
295	    } else if (rx_status.wr_addr < rx_status.rd_addr) {
296	        len = (rx_status.wr_addr + 128) - rx_status.rd_addr;
297	    } else {
298	        len = fifo_cnt > 0 ? 128 : 0;
299	    }