Thread: How to write a driver in C for an IC

Hi everyone,


I want to try to write a driver for this battery fuel gauge http://www.ti.com/lit/ds/symlink/bq2...=1588097914776.

This is my first attempt of writing a driver and it seems like a great opportunity to learn many things through the procedure.
As I mentioned, I've never written a driver before and I want to know If there are any general rules or guides or steps (from where to start and where to finish) that I should follow. There are some general information that I should gather before starting? What I know so far, is that the communication protocol will be the I2C and I will write in C


Thanks in advance
Nick

Hi Salem and thank you for you reply,

Thank you for your reply. I am running a windows machine (if this is what you mean) and I will use the nRF52840 SoC which integrates Arm Cortex-M4F 32-bit processor
nRF52840 Multi-Protocol 2.4GHz SoC - Nordic | Mouser

Originally Posted by Salem

>

> I will use the nRF52840 SoC which integrates Arm Cortex-M4F 32-bit processor
Yes, the other software (maybe an operating system) also running on here at the same time as your driver.

No there is not any OS.

I will read from the chip using the driver and then I will send the data through BLE to the central
- I wrote the code to send the data over BLE

I believe that I used wrong terminology.. I want to write a library and not a driver.. Actually I want to communicate with this particular chip and send the data over BLE
This is a library example I found
GitHub - svcguy/lib-BQ27421: A library based on STM32 CubeMX HAL drivers for interfacing with the Texas Instruments BQ27421 Fuel Gauge IC

I want to write something similar with that from scratch, that's why I'm asking if there are any general rules/guidelines I sould follow.

Thank you Salem,

So far this is the backbone I am thinking to follow:

1. Create a header file and define registers, declare functions, and create structures
2. Create a .c file and define the functions

Tips:
- Use prefixes or suffixes for registers/ functions and structures (e.g. BFG_ for “battery fuel gauge")
- Test the I2C read and write functions and confirm that you can read and write (single and multiple bytes) with success