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Topic: Arduino <> Lobotomized Arduino <> Serial monitor (Read 1 time) previous topic - next topic

Jose Francisco

Hello friends.

I'm trying to talk with an Arduino through another unchipped arduino.

The code is:


void setup() {
  pinMode(2, INPUT);

void loop() {

  if (Serial.available()) {

When I connect with de chipped arduino directly with usb I get "send" every 1/2 seconds and "OK" every time I send something. PERFECT
If I connect using the unchipped arduino (gnd->gnd, vin->vin, tx->tx, rx->rx) I get "send" every 1/2 seconds and "OK" only some times. 1 every 20 times or less. It's... aleatory.

Any idea?


Jose Francisco

Feb 20, 2011, 11:45 am Last Edit: Feb 20, 2011, 11:46 am by Jose Francisco Reason: 1
Hello friends.

Now I'm getting correct answer if I get Rx signal directly from pin 1 of FTDI.

PC <-> USB <->Arduino w/o atmega <-> ftdi pin 1 <-> Chipped board rx pin
                                    tx pin     <-> Chipped board tx pin
                                    5v         <-> 5v
                                    gnd        <->  gnd

Why is this happening?


Why is this happening?

Because you now have the hardware connected correctly.

Jose Francisco

Feb 20, 2011, 01:13 pm Last Edit: Feb 20, 2011, 01:17 pm by Jose Francisco Reason: 1
mnnn... but if I use arduino pin 0 instead of use ftdi pin 1, I can't get correct transmission.

Why can't I use tx and rx pins directly?

PD: Now I'm using a transmission based on Messenger library.


The connection from the "Arduino pin 1" to the FTDI pin is through the chip that you removed.

Jose Francisco


FTDI txd goes to R8 first, atmega pin 2 and j1 pin 0 later.

Am I wrong?

In my test, I can get signal from one side of R8 (ftdi side) but not from the other side.

I have used different arduinos with same result.

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