I have an issue when reading registers using the I2C HAL_Transmit function on a STM32G0

[JWire.1]

Hello I was hoping to get some guidance on what the best way to read an 8bit register, clear and set a few bits, then write back to the same register using the HAL_Transmit function.

I am using a TI LP55231 9 Channel LED driver. Datasheet is located here: https://www.ti.com/lit/ds/symlink/lp55231.pdf

My issue is when I read the registers and step through the code I am not getting the values I am expecting and I believe it has something to do with how the variable types do not match as one is a uint8_t and the other is a pointer.

I got this code originally from github as a place to start located here:

https://github.com/jonathanrjpereira/LP55231-Programmable-9-LED-Driver

The provided code seems to give just very basic user functions but I wanted to expand on the library and see if I could add a few more features to it. I started by testing the existing code and realized some of it is not functional. Such as the channel mapping function and this is how I got to where I am.

The code below are some of the functions where I am getting the warnings "warning: passing argument 5 of 'HAL_I2C_Mem_Read' makes pointer from integer without a cast [-Wint-conversion]"

however if I changed it to a pointer I get errors about preforming logic operations on pointers.

If you would like me to post my entire code I will but Its not to far off from what was posted at the github link. I just adapted it to work on the STM32G0 and cut a few things out as I am using 9 white LEDs instead of 3 RGB.

Thanks.

What is the best way to reslove this issue?

Thanks

/*
 * @brief Selects dimming mode i.e. Log/Linear scale
 * @param channel: LED channel number (0-8)
 * @param control: 0: Linear, 1: Log
 * @retval Status
*/
enum lp_err_code Log_Dimmer_CNTRL(uint8_t channel, bool control){
	if(channel >= Total_Channels){
		return LP_ERR_INVALID_CHANNEL;
	}
	uint8_t reg;
	HAL_I2C_Mem_Read(&hi2c1, (uint16_t)(LP55231_ADDR<<1) |0x01, (D1_CNTRL) + channel, 1, reg, 1, 50);
	uint8_t config = control ? LOG_EN : 0x00;
	reg &= ~(0x20);
	reg |= config;
	HAL_I2C_Mem_Write(&hi2c1, (uint16_t)(LP55231_ADDR<<1), (D1_CNTRL) + channel, 1, &reg, 1, 50);
	return LP_OK;
}
 
/*
 * @brief Assigns a channel to a specific Master Fader
 * @param channel: LED channel number (0-8)
 * @param fader_mode: 0: No Mapping, 1: Master Fader 1, , 2: Master Fader 2, 3: Master Fader 3
 * @retval Status
*/
enum lp_err_code Master_Fader_Map(uint8_t channel, uint8_t fader_mode){
	if(channel >= Total_Channels){
		return LP_ERR_INVALID_CHANNEL;
	}
	uint8_t reg = 0,  config;
	HAL_I2C_Mem_Read(&hi2c1, (uint16_t)(LP55231_ADDR<<1) |0x01, (D1_CNTRL) + channel, 1, reg, 1, 50);
	config = fader_mode;
	config <<= 6;
	reg &= ~(0xC0);
	reg |= config;
	HAL_I2C_Mem_Write(&hi2c1, (uint16_t)(LP55231_ADDR<<1), (D1_CNTRL) + channel, 1, &reg, 1, 50);
	return LP_OK;
}

[TDK · Accepted solution]

Your memory read functions use “reg�? where they should be using “&reg�?.