Arduino I2C to ZSSC3123

[nanana_1011]

Hello!

I want to retrieve the value of C_Config.

My code:

Wire.begin();
Wire.beginTransmission(0x50);
Wire.write(0xA0); // Enter the command mode
Wire.endTransmission();
Wire.requestFrom(0x06, 3); // Retrieve the value of C_Config
byte a = Wire.read();
byte b = Wire.read();
byte c = Wire.read();

But what I get is 255, not the default value.
What is the problem?

https://datasheet.octopart.com/ZSSC3123AA2-T-ZMDI-datasheet-10989346.pdf

 

[ernpao]

I think you need to call beginTransmission (send i2c start and device address) again before requesting for the bytes.

 

[milan.rajik]

ernpao is right.

Wire.endTransmission();

will Stop I2C Comm. So, you have to issue Start I2C again before reading the bytes.

 

[nanana_1011]

Now I add 1 more.
Wire.beginTransmission(0x50);

But all are 255. I see that the IC will send something called slave ACK which is 1 bit.
Do I wait for that ACK before sending requestFrom?

Is my address of the device wrong?
I see that it is set 0101000 as default.
Then is it 0x50?

 

[milan.rajik]

I think the first bit (bit 0) of the address byte is read/write bit. So it you are writing to device then bit 0 of address byte will be 0 and the other address field has to be shifted 1 bit to left to form the address byte.

 

[nanana_1011]

I find that Arduino only needs first high 7 bits. I think it does not need to write last bit.
But I still do not know how to enter command mode and retrieve the value of register.

- - - Updated - - -

Anyone help?

 

[ernpao]

Just read about using wire.requestFrom, apparently you have to use the address device as the argument which as you stated is 0x50. I am assuming the 3 registers starting from 0x06 are the registers you want to read? With the arduino wire library i dont think you can read starting from that address and you have to start from 0x00. So maybe use

byte buffer[10];// just use a large buffer
int ii = 0;
wire.requestFrom(0x50, 10);//request 10 bytes from device
for(ii =0; ii <10; ii++){
buffer[ii] = wire.read();
}
//register 0x06 is in buffer[0x06] and so on