Hardware Serial on Leonardo talking jiberish

Development Tools IDE 1.x
1

I got a Arduino Leonardo board to be able to use a hardware serial while debugging with the pc. Uploading the program works fine and the led gets switched on/off.
The USB "Serial" works.. but the HW "Serial1" talks jiberish (see attached image). Switching baud doesn't help. Also tried all baud rates on the arduino for Serial1
Tried several serial->usb converters to connect to the pc (prolific and ftdi).

Anybody an idea what's going wrong?

BTW.. This site does the same, but doesn't work for me: http://cal-eng.com/?page_id=579

#define DEBUGLED 13
#define BOOTLED 7
 
void setup()  {
  pinMode(DEBUGLED, OUTPUT);          
  pinMode(BOOTLED, OUTPUT);             
  digitalWrite(BOOTLED,HIGH);
 
  Serial.begin(9600);
  Serial1.begin(9600);
}
 
void loop() {
                Serial.println("Hardware serial");
                Serial1.println("Hardware serial 2");
                digitalWrite(DEBUGLED,HIGH);
                delay(500);
                digitalWrite(DEBUGLED,LOW);
                delay(100);
}

image001.png
image001.png808×482 30.6 KB

2

How are the serial lines connected to your PC's COM port?

3

through a header on a generic cable to a serial->usb converter. I attached a photo

IMG_20120417_212001.jpg
IMG_20120417_212001.jpg436×623 120 KB

4

The garbage could be due to a baud rate mismatch. Have you tried other baud rates?

Have you used the generic USB to Serial cable successfully with other projects?

5

I tried all baud rates, as mentioned in my initial post. Also two different serial->usb converters. I used them successfully in other projects.

6

The signals won't jump across that gap - doesn't look to me that you are connected.

7

haha, I see it in the photo.. but the debugging was done before I changed the header to the other part :slight_smile:
The jiberish does come at the expected rate used by the delay.

8

Grounds are connected? The screen shot looks like missing ground data.

9

Yes, ground is also properly connected. Measured everything again, but can't find a wiring fault.
The board is being powered by a USBtinyISPv2.0, so both sides are connected to USB of the same pc.

10

Connected to different ports tho, yes? Not to the same port in parallel?

11

Also with that the photo I took is a bit misleading, because the cable on the right just provides power. It does not show the cable connected on the left.. The board is connected with the mini USB connector for debugging and with the wires on the bottom for the second serial.