Pulse sensors are two pin and operate at 24v (common arduino examples use three pin, and 5-12v)
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This is what I heard last from DAE support on potential Arduino compatibility:
“The pulse meter on our water meter is a dry contact reed switch (The switch may be damaged if input electricity is more than 0.01A, 24V). You might need to talk to tech support from Arduino to confirm the compatibility.”*
I was told by an electrical friend that an optocoupler would be appropriate for signal voltage lowering.
My understanding is that with my particular DAE flow sensor. The sensor generates its own electricity via the flow and outputs 24v signals that could damage the 5v pins on the Arduino. Can I just hook the positive line to an interrupt GPIO on Arduino and assume it's going to work? Do you think I need anything converting the signal.
Pulse Output: 1 liter (0.001 cu meter)/pulse, a dry contact (i.e. no voltage) reed switch with 2 wires, 1.5m. The third party system should not generate electricity more than 0.01A (typically 0.005A like DAE AMR), 24VAC/DC.
This is for sinks, bathroom, toilet in a highly specific research lab. Expect typical use in a household setting. Not a crazy amount.
*Pulse Output: 1 liter (0.001 cu meter)/pulse, a dry contact (i.e. no voltage) reed switch with 2 wires, 1.5m. The third party system should not generate electricity more than 0.01A (typically 0.005A like DAE AMR), 24VAC/DC.
The connecting element does like a hard rubber ball dropen on the floor. Bang, bang, bang before it settles. The same applies to all push button switches and all mechanical contacts.
Wet or wetted contacts are silver with a bit of mercury added to make an amalgam. Otherwise the silver will quickly tarnish and be worn away. Dry contacts are usually some other metal such as tungsten which have less wear because of the hardness of the metal.
Voltage free will operate like an everyday switch.
One end connects to ground, the other to the Arduino input with that input set as inputpullup.
This adds an Arduino internal pullup resistor to the 5v supply.
You will need to add some debounce code for the reed, just as one needs for a switch.
I'd suggest you do some basic Arduino programming study.
Integrating a high voltage reed switch with an Arduino is indeed possible, but it requires some additional components to ensure compatibility and safety. Given that the DAE Flow Sensor operates at 24V and the Arduino typically handles 5-12V, using an optocoupler is a suitable approach to lower the signal voltage and provide electrical isolation between the high voltage reed switch and the Arduino.
Steps to Integrate the Reed Switch with Arduino Using an Optocoupler:
Choose an Appropriate Optocoupler: Select an optocoupler that can handle the input voltage from the reed switch (24V) and provide a suitable output for the Arduino (5V). Common choices include the PC817 or 4N25 optocouplers.
Circuit Setup:
Input Side: Connect the reed switch to the input side of the optocoupler. The input side typically consists of an LED that will be activated by the reed switch.
Output Side: Connect the output side of the optocoupler to the Arduino. The output side usually consists of a phototransistor that will switch on and off based on the input signal.
Wiring:
Connect one pin of the reed switch to the 24V power supply and the other pin to the anode of the optocoupler's LED.
Connect the cathode of the optocoupler's LED to ground through a current-limiting resistor.
Connect the collector of the optocoupler's phototransistor to the Arduino's digital input pin.
Connect the emitter of the optocoupler's phototransistor to ground.
Code:
In your Arduino code, configure the digital input pin connected to the optocoupler's output as an input.
Use the digitalRead function to read the state of the reed switch.
Example Code:
const int reedSwitchPin = 2; // Pin connected to the optocoupler's output
int reedSwitchState = 0;
void setup() {
pinMode(reedSwitchPin, INPUT);
Serial.begin(9600);
}
void loop() {
reedSwitchState = digitalRead(reedSwitchPin);
Serial.println(reedSwitchState);
delay(500);
}
Using an optocoupler will ensure that the high voltage from the reed switch does not damage the Arduino, and it will provide the necessary isolation for safe operation.
BTW this was an original answer of mine, spoofed into an essay by ChatGPT.
"dry contacts" means there is no voltage on either switch contact, neither contact is connected to anything, you could switch 3.3 volts to your Arduino input pin with the reed switch.