[resolved] Using of Tx-1 of an Arduino Board

Development Boards Arduino
1

Hello,

I’m Théo and I’ve an Arduino Pro ATmega 328. I’d like to make something special with my board but I don’t find information that I want.

Actually, I sent a program into the µ-processor of my board. It works, each seconds, my program sends values between 0 and 3000. When I open the Serial Monitor, I’m capable of seeing all the values that are sent via the USB connection between my board and my laptop.

On my laptop, I made a software that is able to read the value sent via the USB connection (serial communication) and this software just update a progress bar in function of the value that it receives.

This is working.

But now, I’d like to forget the USB connection and I’d like to use a Bluetooth module to send the values.

On my Bluetooth module, there are pins. One of them is a Rx pin, to receive data from my Arduino board.

And on my Arduino board, there is 2 Tx pins to transmit data. But, I don’t know which pin I have to choose and plug into my BT module.

My Arduino Board is this one http://www.arduino.cc/en/Main/ArduinoBoardPro, and if you have a look there is Tx-0 and Tx-1.

May someone help me in using one of these pins ?

I saw a sample http://arduino.cc/en/Reference/SoftwareSerialExample but I think it’s close to my problem but here it’s probably to use the receive pin of the Arduino board.

2

toofil:
And on my Arduino board, there is 2 Tx pins to transmit data.

Um, with the picture you posted, I only see a Tx on pin 1 and an Rx on pin 0. If your board is mislabled, just know that pin 0 is Rx.

To do serial, just attach the Tx of one board to the Rx of the other and vice versa (each transmits to the receiver of the other).

SoftSerial is what you want if you want to be able to talk to two serial devices (eg PC and blutooth module) at the same time.

3

WizenedEE:

toofil:
And on my Arduino board, there is 2 Tx pins to transmit data.

Um, with the picture you posted, I only see a Tx on pin 1 and an Rx on pin 0. If your board is mislabled, just know that pin 0 is Rx.

…

His confusion is warranted I think. Pin 0 on the side of the pcb is labeled RX, which could also be read as RX0. Pin 2 is TX, which could be read as TX1. Atleast!, IF you do not notice that the TX,RX characters are 90 degrees rotated wrt. the numbers of the pins.

However, on the black connector near the battery connector are a TX-0 (a dash through a circle means “zero”) and a RX-I (is a capital “i”, easily mistaken as RX-1). Which to the uncritical eye suggests these are a second UART, however strangely mixing the TX and RX pairs up.

The confussion is solved with a look in the schematic of the pcb:

http://arduino.cc/en/uploads/Main/Ardui … ematic.pdf

There you will find that there is only one UART channel (1 TX/RX pair), and both TX pins are connected to PD1 of the atmega chip, and both RX pins are connected to PD0 of the chip. Bad printing mask design.

4

Hello,

Finally I succeeded in plugging my pins as well.

Actually, when someone wants to use a Bluetooth device with an Arduino board, we are obliged to connect Rx pin of BT to Tx of Arduino Board and also Tx pin of BT to Rx of Arduino Board.

And be careful if your board is a 5V, make a conversion with a bridge divider to go on the BT module.

Thank you all,

Bye

5

It’s a typo. On the 6-pin header, that should be “TX-O”, with the letter O, not number zero. The O and I are for out and in, respectively, to help clear up the DTE/DCE confusion of who transmits on a pin labelled “TX”.

/mike