Atlas Load Cell Reader

Atlas is a load cell reader with a CAN interface design for Hot & Cold Tests.
The chip consist of:

STM32U575 CPU

NAU7802 LOAD CELL READER

2x Load Cell Interfaces

2x CAN interfaces

SWD/JTAG

USB-C

The zephyr driver used for NAU7802 Load Cell can be found here:
https://github.com/TinNotTim/nau7802_loadcell_zephyr_driver

Page shows how to integrate external driver module to zephyr build, but atlas.overlay files change.
STM32 and NAU7082 communication via I2C2 (I2C1 is occupied by CAN PB8 PB9)
Atlas chip connects NAU7802 drdy (data ready) = STM32 GPIOA8 (PA8).
NAU7802 SCL = STM32 SCL (PB13)
NAU7082 SDIO = STM32 SDA (PB14)

State of project

The produced physical Atlas 2024 version chip has an error with I2C connection between STM32 and NAU7802
where the SCL and SDA are incorrectly set to (PB14, PB15).
However, looking at the PCB in hardware folder you find the 2023 version only...
In this 2023 version the I2C error has been corrected by Zhizhifeng.

Debug:

Atlas debugging is best performed via ST-LINKV3 JTAG. Useful files for STM32 dtsi:

software/ext/zephyr/modules/hal/stm32/dts/st/u5/stm32u575zitxq-pinctrl.dtsi

software/ext/zephyr/dts/arm/st/u5/stm32u5.dtsi

Flashing over USB-C takes ~3 min. ST-LINKV3 is much quicker.
Atlas chip should be started in boot mode.

Guide to setup zephyr project for Atlas is found in software directory.
https://github.com/aesirkth/atlas_load_cell/tree/master/software