how can simulate serial input at PIN 0 easily??

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi,

What's the easiest way to simulate some serial input for PIN 0 on my Arduino board? Any ideas?

I've basically still stuck trying to get my RF transmitter & RF receiver working (from thread http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1277035059) & I'd like to prove my receiving Arduino can receiver incoming serial from PIN 0 ok.

Note - I'm running a MacBook myself, but there are a couple of older PCs in the house. Not sure if there another household device I could use? Would only real approach be to find a PC with serial point and open up the wiring on one end and apply this to PIN - would one of the two wires go to PIN 0 and the other to GND on the arduino board in this case?

thanks

2

The simplest thing to do would be to put gibberish into the rx buffer. To do this put a wire in the rx pin and another wire in the +5v pin. then very lightly rub the ends of the wires together. The scratchy electrical action of the of the two wires rubbing on each other will put the gibberish in the rx buffer which you should be able to see.

3

Actually I've seems this when connecting the RF receiver DATA output to PIN 0. I get a random character appearing.

What would be the next step after this to simulate some real commas through?

4

I'd jumper the tx/rx on the gizmos and see if what is sent gets sent back.

5

Thanks, I didn't think of this :-X

6

You can send serial data... of your choosing, i.e. you type something and that goes to your Arduino... to your Arduino from the same software as that which you use for programming it!

Having said that... if you are connecting some serial thing to the Arduino, then, unless you have a severe pin shortage, due to other requirements, you should connect the other something via the NewSoftSerial library and a different pin, so that your other serial thing and your programming cable don't have to be endlessly swapped.

If you are into connecting serial things, be sure you know that "RS-232" and "serial" do not mean the same thing. You cannot plug an RS-232 device directly to an Arduino's serial port.

Using programming software to send serial data explained at...

7

If not sure of your wireless connection why not connecting by wires between your arduino and the other equipment

8

Thanks. Good call re 1. Re 2 I had tried this and it didn't seem to work however I wasn't sure how valid this was a test. I'll good back and retest as this could be a problem (ie when doing the constant on, constant off test the receiver end didn't seem to be replicating what was at the transmitter)

So just to double check, the voltage (High/Low) should simple reflect that of the transmitter correct? So this means and of the talk of synch of data signals is taken out if the equation.

9

update:

  • Ardurino's alone - So when I connect the PIN1 TX output from board one to the PIN0 RX input of board two directly the serial communications works like a charm, no problems.

  • RF Units Alone - When I apply to the RF transmitter DATA pin:
    (a) 5V - the RF receiver data pin goes to 0V
    (b) 0V - receive output jumps around a bit in the range of around 0.5V ?? (doesn't seem good)

Any ideas why this would be? A faulty receiver?

thanks

10

Some RF transmitters & receivers don't like very much steady states.
You'd better test with a pattern.
Look at the data sheet of your RF units. They some time need a continuous flow of data to keep in synch each other.