IanalogRead2()

IanalogRead2() converts the 4~20mA input value to the specified integer range.

int32_t IanalogRead2(uint8_t ch, int32_t min, int32_t max)

This example scales the MPINO-8A4R(T)-S 4–20mA input A2 to 0–100%.

void setup() {
  Serial.begin(115200);
}
 
void loop() {
  const int32_t percent = IanalogRead2(A2, 0, 100);  // Scale the A2 4–20mA input to an integer percentage.
  if (percent == ANALOG_READ2_ERROR) {
    Serial.println(F("4-20mA input error"));
  } else {
    Serial.print(F("A2: "));
    Serial.println(percent);
  }
  delay(500);
}

• In this example, A2 is a current input on MPINO-8A4R(T)-S. For another product, check its pin map for supported 4–20mA channels and wiring.
• An input of approximately 3.6~4.0mA returns the normal value 0; inputs below 3.6mA return an error value.
• Error values help detect open circuits. The user must implement final alarms and safety actions in the program.
• IanalogRead2() and IanalogRead2f() also return 65535 on error, rather than a user-range value. Check for errors before using the result.
• The full int32_t range is available for min~max in IanalogRead2(), but if the normal range includes 65535, it cannot be distinguished from an error value.
• analogRead2Avgf() uses state and a buffer separate from analogRead2Avg(). Using both increases SRAM usage.
• If samples is 0 or memory allocation fails in analogRead2Avgf(), it returns the current valid corrected value as a float.
• On MPINO, do not use analogRead2() on voltage/NTC channels that are not 4~20mA inputs.
• For MPINO products requiring analogReference(EXTERNAL), set it first in setup().
• IanalogWrite2() and IanalogWrite2f() are convenience outputs dedicated to 4~20mA. Avoid alternating them with IanalogWrite() on the same channel.
• The analog output circuit requires an external 12~24V supply. USB power alone may not provide normal output.
• Verify actual current input/output with measuring instruments after preparing a test product.

• IanalogRead2f() View detailed description

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