Warren (Customer) asked a question.

Edited September 12, 2025 at 3:38 AM
Terminal Block Connectivity Issues

Hi there,

 

I'm having some issues with wiring an A02YYUW ultrasonic sensor to the P1AM. Without any terminal block on the GPIO shield header pins with a direct connection, I'm reading the sensor perfectly fine. However, once I add one of the recommended AutomationDirect terminal blocks to the header of the GPIO shield, I simply get no values. The sensor is a UART-based sensor, so I'm looking for HEX into the P1AM. I've tried the screw and spring-loaded terminal blocks with no luck. I don't have a scope to visualize that the serial is being generated, but with a multimeter, I can confirm proper output voltage of 3.3V on the sensors' TX pin.

 

Any suggestions?

 

Thanks,

 

Warren

 

EDIT: The sensor wiring is coming in via an M12 panel mount connector. It makes a run of about 9 inches and is crimped with a ferrule before it reaches the P1AM.

  • 8 answers
  • 171 views

  • FACTS_AdamC (AutomationDirect)

    Could you provide a picture of the wiring with and without the terminal block?

    • Warren (Customer)

      Thanks for the reply.

      Picture one is with ferrules and the spring-loaded terminal block. Picture two is with dupont jumpers right into the GPIO. Both ways, I have terminated/connected into the rear end of the M12 to bypass any issues with wiring inside the panel to knock out that possibility.

      Photo 1Photo 2 

       

      Picture 3 is just a photo of the incoming hex when wired with the dupont jumpers.

      Photo 3

      Expand Post

      • FACTS_AdamC (AutomationDirect)

        It doesn't look like your pictures came through

      • Warren (Customer)

        Apologies, I had responded via email, and I guess the images didn't transfer over. I just edited my post and added them.

      • FACTS_AdamC (AutomationDirect)

        On your ferruled connected, I would try and check continuity on the plugging end of the terminal block (opposite of were you insert the ferrule and where it plugs into the P1AM-GPIO). I do this with a small piece of solid core wire for quick sanity checks

      • Warren (Customer)

        I just ran the continuity test, I do have continuity between sensor and the rear of the terminal block. Additionally, I threw together some loopback code (below) and jumped TX and RX together and can receive serial perfectly fine through the loopback. Quite strange in my opinion.

        1. #include <Arduino.h>
        2.  
        3. void setup() {
        4. Serial.begin(115200);
        5. while (!Serial);
        6.  
        7. Serial1.begin(9600);
        8.  
        9. Serial.println("Loopback Monitoring Initialized");
        10. }
        11.  
        12. void loop() {
        13.  
        14. if (Serial.available()) {
        15. char c = Serial.read();
        16. Serial1.write(c);
        17. }
        18.  
        19. if (Serial1.available()) {
        20. char c = Serial1.read();
        21. Serial.write(c);
        22. }
        23. }

         

        Expand Post

 

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