Audio Output with Max Carrier

Official Hardware Portenta Family Portenta Max Carrier
1

Hi there^^

i recently bought the Portenta Max Carrier and i would like to output (DAC) some audio-signlas.
Baseically the question is: How to do so?
Since the onboard DAC-chip CS42L52 on the Max Carrier is communicating with the Portenta via I2C the question is:

  1. on which channel of the 3 I2C-channels of the Portenta the CS42L52 is connected to?
  2. what is the I2C-address of the CS42L52 on the Max Carrier

I would also appreciate if anyone can link me to a propper and great manuel/datasheet which can answer my question or at least help me to get better in this problem.

Best Greetings,

alexbau

2

Potentially, you know these documents (but they do not tell you the I2C slave address of Audio chip):
Arduino Max Carrier documentation

Mouser Max Carrier documentation

Actually, you could find the potential I2C slave address in Audio chip datasheet:
CS42L52 datasheet

I2C slave address is:

  • b'1001_01AD0 + R/nW bit
    So, a 7 bit address where bit 0 is set as 0 or 1 via hardware (no idea without schematics).

If you do not find schematics (I could not!), or you cannot find I2C address in Arduino code - there is option to use I2C on Portenta and to try to find a valid slave address and ChipID of audio chip:
If you try I2C with several I2C slave addresses - iterate over 128 -1 possible addresses (slave address 0 is General Call - no need to try) - and you find a slave - try to read the register with ChipID for audio chip. If it matches - you have found it.

But based on Audio chip datasheet: just try slave addresses as b'1001010 and b'1001011 - then you can find ChipID of this chip (or any other register value which makes sense).

3

Nice Great big THX
it works to read the ChipID (1st register on the CS42L52)
Also the others are readable :grinning:

#include <Wire.h>

void setup() {
  Wire.begin();        // join i2c bus (address optional for master)
  Serial.begin(115200);
}

void loop() {
  Wire.beginTransmission(0x4a); // 0x4a = 0b1001010 (6MSB for Chip-Address + AD0 = 0)
  Wire.write(0x01); // Instruction 0x01 is queued which will be read as the Register-Address to be read from by the CS42L52
  Wire.endTransmission(); // Instructionpackage (Chip-Address +  Register-Address) will be sended to the CS42L52

  Wire.requestFrom(0x4a, 1); // requesting the 1byte long answer (content of register 0x01 = ChipID + Chip-Revision) from the CS42L52

  while (Wire.available()) { 

    uint8_t c = Wire.read(); // reading the answer

    Serial.println(c);         // printing the answer

  }

  delay(1000);
}

The CS42L52-Datasheet was very helpfull THX again

4

Cool - well done!

5

Now that i can read all the setting registers and manipulate them is the question:
How to make ths audio DAC to put out something (first just a DC signal at some certain values)
i didnt see a register in the manual to do so
where/what is the data register, where i can transfer a value from the portenta via I2C or some think else that makes the DAC putting out the representiv voltage?

7

Excellent answers