IanalogWrite2f() converts a user floating-point value to the 4~20mA output range.

void IanalogWrite2f(uint8_t ch, float min, float max, float value)

void setup() {
  Serial.begin(115200);
}
 
void loop() {
  uint16_t raw2 = analogRead2(0);
  int32_t filtered2 = analogRead2Avg(0, 5);
  float filtered2f = analogRead2Avgf(0, 5);
  float currentmA = IanalogRead2f(0, 4.0F, 20.0F);
 
  if (raw2 == ANALOG_READ2_ERROR || filtered2 == ANALOG_READ2_AVG_ERROR ||
      filtered2f == (float)ANALOG_READ2_AVG_ERROR ||
      currentmA == (float)ANALOG_READ2_ERROR) {
    Serial.println("4-20mA input error");
    delay(500);
    return;
  }
 
  int32_t percent = Iscale((int32_t)raw2, 0, 32767, 0, 100);
 
  IanalogWrite2(0, 0, 100, 50);       // 50% → approx. 12mA
  IanalogWrite2f(1, 0.0F, 10.0F, 2.5F); // 25% → approx. 8mA
 
  Serial.print("4-20mA raw: ");
  Serial.println(raw2);
  Serial.print("4-20mA filtered: ");
  Serial.println(filtered2);
  Serial.print("4-20mA filtered float: ");
  Serial.println(filtered2f, 2);
  Serial.print("percent: ");
  Serial.println(percent);
  Serial.print("current: ");
  Serial.println(currentmA, 2);
 
  delay(500);
}

• Set the module DIP switches and wiring for 0~20mA current I/O.
• 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.

← Built-in Command List