Arduinio and Photon Serial Communication

[Judd]

So I am becoming interested in IoT projects and one thing I need to do is to send information from one Arduino to another. I have searched many guides, followed them, and yet it is not working. I now believe that I am doing something wrong that I cannot pinpoint.

 

The project looks like this,

 

Arduino has a 5v relay connected to the Arduino and a 20v power supply, with a 24v DC motor as a load. In the Arduino's code, I have it set up to look for a 1 or 0 in the serial monitor, 1 turns the motor on, and 0 turns it off. This code works great, no errors.

 

Code:

int motorport = 9;
int motorspeed = 0;

void setup() {
pinMode(motorport, OUTPUT);

Serial.begin(9600);

Serial.println("Type 1 to start motor, type 0 to stop motor.");
}

void loop() {
if(Serial.available() > 0){
 motorspeed = Serial.read();
 motorspeed = motorspeed - 48;
 
 Serial.println("Type 1 to start motor, type 0 to stop motor.");

      if(motorspeed == 1){
      Serial.println("Motor ON");
      }

      if(motorspeed == 0){
      Serial.println("Motor OFF");
      }
}

if(motorspeed == 1){
   digitalWrite(motorport, HIGH);
}

if (motorspeed == 0){
   digitalWrite(motorport, LOW);
}
}

 

I now have a Particle Photon(Basically another Arduino but connected to Wi-Fi) with a wire bridging the Photon's TX and the Arduino's RX pins. I have also connected the grounds of both chips. All the code has to do is send a 1, wait for a second, send a 0, wait then repeat. Using Arduino's serial monitor I can confirm it sends a 1 and then a 0 alternating every second. However, it seems to only send data for maybe 5 seconds, then it quits. But during these seconds, the Arduino is not receiving anything as the motor does not start or stop.

 

Code:

 

void setup() {
Serial.begin(9600);
}

void loop() {
Serial.println(1);
delay(1000);
Serial.println(0);
delay(1000);
}

 

Using Tinkercad's circuits section, I created a quick model of my setup,  imagine the transistor is a 5V relay and the battery is a 20v power supply, and the right Arduino is a Photon.

https://www.tinkercad.com/things/5Oc625SgnYq-arduino-to-arduino-comm/editel

 

Now, when I run the simulation, it works fine, so this leads me to believe the Photon is the problem. Any ideas? Thanks for the help.

[kevdagoat]

The photon is 3.3v (I think) and the Arduino is 5v TTL.

 

You will have to use a logic level converter

[Judd]

48 minutes ago, kevdagoat said:

The photon is 3.3v (I think) and the Arduino is 5v TTL.

 

You will have to use a logic level converter 

I thought about this, however, the website said that the Arduino will accept a 3.3v input as a HIGH input. I really do not know though. I'll order some because they are not expensive. I'll order them and update if it works or not. Thanks for the suggestion.

[kevdagoat]

1 hour ago, Judd said:

I thought about this, however, the website said that the Arduino will accept a 3.3v input as a HIGH input.

The Arduino will not accept 3.3v using HardwareSerial nor SoftwareSerial.

 

I have tested this in the past with a 3.3v TTL GPS module to no avail.

[Judd]

23 hours ago, kevdagoat said:

The Arduino will not accept 3.3v using HardwareSerial nor SoftwareSerial.

 

I have tested this in the past with a 3.3v TTL GPS module to no avail.

Thank you for the confirmation, I am getting the converters Sunday and will try them when they get here. Thanks.