I am studying a bio-medical instrument where glucose in blood is measured using light reflection principle as shown:
LED is blinked at fast rate and both LED's ADC reading is taken using single photo diode which is used as sensor. Since single sensor is used, I have to switch LED and corresponding ADC is stored in single channel ADC.
SPI based ADC is preferred in this case since it will be fast compared to I2C. But due to unavailability of SPI port pins, if I implement it with I2C, does it makes a difference considering switching of LED's takes place at high rate?