SparkFun PRO MICRO not running program

Other Hardware 3rd Party Boards
1

Hello
I am using a couple of PRO MICROs that I got from EBAY.
After I load the program successfully, I notice that the program starts running only when I open the serial monitor. Also, it stops running when I close the monitor window.
I would appreciate any idea to try solving this issue.
Mike

2

(deleted)

3

This is my code:
When this code is running, I should see the TX-RX LEDS blinking. It happens only if I open the serial monitor.

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

void loop() {
Serial.println("OK");
delay(2000);
}

4

MDNARD10:
When this code is running, I should see the TX-RX LEDS blinking.

You're making a big assumption about how the Micro handles those LEDs. Have you closely examined the low level CDC code from the Arduino core library? The fact that the LEDs are not blinking is in no way proof that the code is not running.

Blink an LED using digitalWrite() if you want to prove to yourself that the code is running.

5

The PRO MICRO has no available LED. So I just used a digital output and monitored with a multimeter
Indeed it runs. The fact that serial activity monitoring is different with this board than the other Arduino boards such as UNO, MEGA, NANO.. has mistaken me.
Thanks for your assistance.
Mike

6

You're welcome. I'm glad if I was able to be of assistance. Enjoy!
Per

FYI, you can use the RX and TX LEDs on the board as built-in LEDs if you like. Their pins are named LED_BUILTIN_RX and LED_BUILTIN_TX.

7

Yes, I tried it. It works.
Very useful in cases we need some monitoring with this board, while running without a PC.
Thanks
Mike

8

Hey
We are using a pair of PRO MICROs got form EBAY
After that we have load the random program successfully. I watch it;s the program start only when i open the serial monitor. Also, it stops running when i closed the monitor window
I recommend any idea to try solving this issue MIKE

9

Hey
We are using a pair of PRO MICROs got form EBAY
After that we have load the random program successfully. I watch it;s the program start only when i open the serial monitor. Also, it stops running when i closed the monitor window
I recommend any idea to try solving this issue MIKE

10

aksh012:
Hey
We are using a pair of PRO MICROs got form EBAY
After that we have load the random program successfully. I watch it;s the program start only when i open the serial monitor. Also, it stops running when i closed the monitor window
I recommend any idea to try solving this issue MIKE

You had better post your code so that people can have a look at it then.