analogReadInit() sets the sampling rate of the analog input module.

void analogReadInit(uint16_t sps)

void setup() {
  Serial.begin(115200);
 
  // Use autocomplete constants
  analogReadInit(IANALOG_SPS_250);
}
 
void loop() {
  for (uint8_t ch = 0; ch < 4; ch++) {
    Serial.print("CH");
    Serial.print(ch);
    Serial.print(" = ");
    Serial.println(analogRead(ch));
  }
}

• Settings other than SPS, such as PGA, input MUX and Single-shot mode, are not changed.
• Higher SPS reduces conversion wait time, but check for value fluctuations due to field wiring and signal noise.
• The internal ADS1118 maximum RATE is 860 SPS. Since the same channel is converted twice, the maximum requested return target is 475 SPS.
• analogReadInit(128) uses the nearest higher RATE of 250 SPS, rather than 256 SPS, which the ADS1118 does not provide.
• SPI communication and function processing add time, so the actual measurement SPS may be lower than the target.
• analogRead() converts the same channel twice to prevent channel-value displacement. Include both conversion times when calculating the total channel update time.

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