Why write 0x20 to I2CADC's CONFIG?

Products & Technology Grove
#1

In the examples I see (seeedstudio.com/wiki/Grove_-_I2C_ADC) when using the I2CADC:

void init_adc() { Wire.beginTransmission(ADDR_ADC121); // transmit to device Wire.write(REG_ADDR_CONFIG); // Configuration Register Wire.write(0x20); Wire.endTransmission(); }

And:

class I2cAdc: def __init__(self): i2c.write8(REG_ADDR_CONFIG, 0x20)

…why is 0x20 always written to the config register? What does that do?

#2

The relevant docs start on page 18 of this url: seeedstudio.com/wiki/images/ … asheet.pdf

So the config register is indeed #2, and the value 0x20 sets the D5 bit to enable “automatic conversion mode” (page 27).