Read RX pin

Projects General Guidance
1

Hi,

I send serial data through the USB connexion, and I'd like to read these datas on my oscilloscope.
I put my probe on the Rx pin, but it's always at LOW level.

The Rx pin isn't the copy of the Rx data coming from USB?
How to do then? I tried by sending with Serial.print the incoming datas but it does'nt seem to work...

Thanks a lot,
A.

2

The serial lines normally idle HIGH so I am surprised you are getting a LOW.

You have not said what Arduino you have. Pins 0 and 1 should show the data coming into and going out of an Uno's Atmega 328. Similarly on a Mega. But on a Leonardo they are separate as Serial1 and are not part of the USB system.

...R

3

I have a Micro...

So I can't get my data this way?

Thanks

4

Try the tx pin.

5

Anduriel:
I have a Micro...

So I can't get my data this way?

I believe you can't. The Micro is similar to a Leonardo and I don't think the USB serial data is available on any pins.

...R

6

Anduriel:
How to do then? I tried by sending with Serial.print the incoming datas but it does'nt seem to work...

On the Micro/Leonardo:

 void setup() {Serial.begin(19200); Serial1.begin(19200);}
void loop() {
   if (Serial.available()) Serial1.write((byte)Serial.read());
   if (Serial1.available()) Serial.write((byte)Serial1.read());
}

Of course set the baud rates to your desired rate. The data arriving on USB should come out the TX pin (Pin 1).