Two Byte commands not supported

[paper42]

I was trying to use this code with the SCD41 sensor datasheet, but it turns out it uses 2 byte commands which isn't supported by this library.

this library only sends Address MSB here and skips Address LSB

Simply modifying the code to send the second byte after an ack of the first command byte worked, would it be possible to support this?

[ADBeta]

I will look into adding this in the next version of the library.

[HardwareHarry]

By sheer coincidence I have been working on a driver for the Sensiron SCD40/41 sensors on CH32V003 with CH32FUN. It makes use of the I2C_LIB extension and implements a couple of new functions to allow for the two byte command and 3 byte data words that the sensor uses. If you'd like to try it, it is here and any feedback would be greatly appreciated.

@ADBeta, I'd like to try and add these extensions for I2C 16 bit commands to your library if you are willing.

[orbitalair]

I have code already tested for this, for a 256kb eeprom that uses 2 byte addressing.
my demos github,
https://github.com/orbitalair/Ch32v003_demos

My code is here under lib/ in lib_i2c I added read_2ba, and write_2ba. I thought it easier and clearer to have new functions for this.

I see I made specific notes to the eeprom in the comments, I can change that.

I can help dev or test whatever you all come up with.

Hope this helps.

[ADBeta]

Thanks everyone, I'm reviewing your work(s) now and will pull stuff from them - I have been working on this project slowly in the background to add more features and improve it more, sorry for the delay

[ADBeta]

@HardwareHarry @orbitalair I have just pushed a new testing version to https://github.com/ADBeta/CH32V003_lib_i2c/tree/testing

could you both test out its basic performance with the SCDxx please and let me know how it does.
The i2c_write_reg and i2c_read_reg both now take up to 4 bytes as a register chunk, but otherwise works as before.

i2c_device_t and the init procedure has been updated, to specify the Clock Hz in the device, and the number of register bytes
for example this should be correct for the SCD41

// NOTE: Please test this multi-byte register stuff
// Create a Device Struct - This tells the I2C functions what address type
// and value is being used.
// In this example, a simple 7bit address is being used, with 2 bytes
// for the register/command section
i2c_device_t dev = {
	.clkr = I2C_CLK_400KHZ,
	.type = I2C_ADDR_7BIT,
	.addr = 0x62,
	.regb = 2,
};

// Initialise the I2C Interface for this device
if(i2c_init(&dev) != I2C_OK) printf("Failed to init the I2C Bus\n");

Let me know if you have any troubles :)
This isn't quite finished yet so ideas are welcome, I just don't have any of those sensors on hand

[orbitalair]

Thanks, I got the code but didnt read carefully enough. my 2byte addr devices uses 10bit addressing.
but otherwise I got the code ported and compiling ok for my 24LC256 eeprom demo.