# Arduino Leonardo and FT232RL

**URL:** <https://forum.arduino.cc/t/arduino-leonardo-and-ft232rl/1314854>\
**Category:** General Guidance\
**Created:** [October 24, 2024, 2:59pm UTC](https://forum.arduino.cc/t/arduino-leonardo-and-ft232rl/1314854 "2024-10-24T14:59:13Z")\
**Posts on this page:** 13\
**Page:** 1

<div class="post-metadata">

**Author:** ![brainsold](https://avatars.discourse-cdn.com/v4/letter/b/919ad9/32.png) [@brainsold](https://forum.arduino.cc/u/brainsold)\
**Post date:** [October 24, 2024, 2:59pm UTC](https://forum.arduino.cc/t/arduino-leonardo-and-ft232rl/1314854/1 "2024-10-24T14:59:13Z")

</div>

Hello Guys,

First, thanks for looking! 🙂  
I want to make a project, already invented. But unfurtunatly i´ts not working.  
I want to copy data from one computer and send to another one but simulating that I typing on the keyboard.  
Im using a leonardo and a FT232RL. I leave a link to video that I uploaded-\> [https://youtu.be/VIgG78R5vmk](https://youtu.be/VIgG78R5vmk)

And this is the code for debugging (created my chatGPT):

```arduino
void setup() {
  Serial.begin(9600); // Start USB Serial communication
  Serial1.begin(9600); // Start Serial1 communication via TX/RX pins

  // Send an initial debug message
  Serial.println("Arduino Leonardo ready! Waiting for data...");
}

void loop() {
  // Check if data is available from the USB Serial (Serial)
  if (Serial.available()) {
    char character = Serial.read(); // Read the received character from USB
    Serial1.write(character); // Send the character via Serial1 (TX/RX pins)

    // Debug: Print the character to the Serial Monitor (USB)
    Serial.print("Character received via USB: ");
    Serial.println(character);

    // Debug: Confirm the character was sent via Serial1 (TX/RX)
    Serial.println("Character sent via Serial1 (TX/RX)");
  }
}

```

---

<div class="post-metadata">

**Author:** ![horace](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/horace/32/1014299_2.png) [@horace](https://forum.arduino.cc/u/horace)\
**Post date:** [October 24, 2024, 3:23pm UTC](https://forum.arduino.cc/t/arduino-leonardo-and-ft232rl/1314854/2 "2024-10-24T15:23:47Z")

</div>

> [@brainsold](#):
>
> But unfurtunatly i´ts not working

what does it do? not compile, link and upload? not give correct results?

for Serial1 test try

```cpp
// Arduino Leonardo Serial1 test

// Serial leonardo has native USB (uart0)
// Serial1 is hardware serial port pin 1 is Tx and pin 0 is Rx

// for loopback test connect pin 0 to pin 1

// for RS232 shield connect pin 1 to Tx and pin 0 to Rx
// for loopback test connect 9 pin D connector pins 2 and 3

unsigned long time;

void setup() {
  Serial.begin(115200); // initialise serial monitor port
    while(!Serial); // wait for serial stream to open
  Serial1.begin(115200); // initialise Serial1
  Serial.write("Arduino Leonardo Serial1 test - for loopback test connect pin 1 Tx to pin 0 Rx\n");
}

void loop() {
  if (Serial1.available()) { // read from Serial1 output to Serial
    Serial.write(Serial1.read());
  }
  if (Serial.available()) { // read from Serial outut to Serial1
    char inByte = Serial.read();
    //Serial.write(inByte); // local echo if required
    Serial1.write(inByte);
  }
}

```

to test connect pin 0 to pin 1 - characters entered on serial monitor keyboard should echo back to display

how have you connected the FT232RL? give a link to it?

---

<div class="post-metadata">

**Author:** ![brainsold](https://avatars.discourse-cdn.com/v4/letter/b/919ad9/32.png) [@brainsold](https://forum.arduino.cc/u/brainsold)\
**Post date:** [October 24, 2024, 3:39pm UTC](https://forum.arduino.cc/t/arduino-leonardo-and-ft232rl/1314854/3 "2024-10-24T15:39:37Z")

</div>

Hello Horace,

Thanks for your reply. I connect the PC "A" the one I want to send the data, to leanerdo by USB cable, than the on PIN 0 (RX) of Leonardo I conect it to the PIN TX on the FT232RL.  
Leonardo PIN1 (TX) to FT232RL (RX). that the FT232RL to PC "B" with a USB cable. I left a video on the post, I dont know if you saw irt or not, if not please take a look.

Best regards,  
Pedro

---

<div class="post-metadata">

**Author:** ![horace](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/horace/32/1014299_2.png) [@horace](https://forum.arduino.cc/u/horace)\
**Post date:** [October 24, 2024, 3:44pm UTC](https://forum.arduino.cc/t/arduino-leonardo-and-ft232rl/1314854/4 "2024-10-24T15:44:04Z")

</div>

try

```arduino
// for RS232 shield connect Leonardo pin 1 to Tx and pin 0 to Rx

```

for loopback test connect 9 pin D connector pins 2 and 3

---

<div class="post-metadata">

**Author:** ![brainsold](https://avatars.discourse-cdn.com/v4/letter/b/919ad9/32.png) [@brainsold](https://forum.arduino.cc/u/brainsold)\
**Post date:** [October 24, 2024, 6:38pm UTC](https://forum.arduino.cc/t/arduino-leonardo-and-ft232rl/1314854/5 "2024-10-24T18:38:24Z")

</div>

Hello horace,

The loopback of leonardo gave me the next message:

 ![imagem](https://europe1.discourse-cdn.com/arduino/original/4X/e/0/e/e0ec728b43eaca8b0ba160caeb48e33b9b56fea7.png)

this test Im not understanding! But Im not using RS232 connector.

Regards,  
Pedro

---

<div class="post-metadata">

**Author:** ![brainsold](https://avatars.discourse-cdn.com/v4/letter/b/919ad9/32.png) [@brainsold](https://forum.arduino.cc/u/brainsold)\
**Post date:** [October 25, 2024, 9:04am UTC](https://forum.arduino.cc/t/arduino-leonardo-and-ft232rl/1314854/6 "2024-10-25T09:04:30Z")

</div>

Anyone!? 😇

---

<div class="post-metadata">

**Author:** ![horace](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/horace/32/1014299_2.png) [@horace](https://forum.arduino.cc/u/horace)\
**Post date:** [October 25, 2024, 9:26am UTC](https://forum.arduino.cc/t/arduino-leonardo-and-ft232rl/1314854/8 "2024-10-25T09:26:01Z")

</div>

> [@brainsold](#):
>
> But Im not using RS232 connector.

can you give a link to the device you are using? or a photo?

---

<div class="post-metadata">

**Author:** ![brainsold](https://avatars.discourse-cdn.com/v4/letter/b/919ad9/32.png) [@brainsold](https://forum.arduino.cc/u/brainsold)\
**Post date:** [October 25, 2024, 9:37am UTC](https://forum.arduino.cc/t/arduino-leonardo-and-ft232rl/1314854/9 "2024-10-25T09:37:11Z")

</div>

Hello @horace,

Heres is the photos and I also leave the link to the video that I recorded with all connected:

[![](https://europe1.discourse-cdn.com/arduino/original/4X/0/6/a/06a2673e5b7e264aa3a7bbdb7ba3337176ad3801.jpeg "Arduino Leonardo and FT232RL") ](https://www.youtube.com/watch?v=VIgG78R5vmk)

 ![arduino-leonardo-r3](https://europe1.discourse-cdn.com/arduino/original/4X/e/6/b/e6b6055dd16f0e180ca3b0f5fbcf9c2c5b4befd2.jpeg)

 ![FT232RL](https://europe1.discourse-cdn.com/arduino/original/4X/e/e/d/eedd7c124a761c3caee6633e73d421fb4f89a3d2.jpeg)

Thanks

---

<div class="post-metadata">

**Author:** ![horace](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/horace/32/1014299_2.png) [@horace](https://forum.arduino.cc/u/horace)\
**Post date:** [October 25, 2024, 10:18am UTC](https://forum.arduino.cc/t/arduino-leonardo-and-ft232rl/1314854/10 "2024-10-25T10:18:31Z")

</div>

looks like you are connecting to a PC using a FTDI type USB to TTL serial breakout board not a RS232 module

using the program from post 2 with connections  
Leonardo pin 1 to FTDI RXD  
Leonardo pin 0 to FTDI TXD

photo (note I am using a Things UNO board which is based on a Leonardo not a UNO)

 ![image](https://europe1.discourse-cdn.com/arduino/original/4X/a/f/9/af9f3bf3e71fa55d838a37753060aa4a88758ecc.jpeg)

Leonardo serial monitor output

```arduino
Arduino Leonardo Serial1 test - for loopback test connect pin 1 Tx to pin 0 Rx
hello from PC
test2 from PC 1234567890
test3 from pc 1111111111111111111111111111111

```

teraterm terminal emulator on PC

 ![image](https://europe1.discourse-cdn.com/arduino/original/4X/a/7/8/a78d94180c46b150062b83031a5dd07d915a6eb9.png)

---

<div class="post-metadata">

**Author:** ![brainsold](https://avatars.discourse-cdn.com/v4/letter/b/919ad9/32.png) [@brainsold](https://forum.arduino.cc/u/brainsold)\
**Post date:** [October 25, 2024, 4:18pm UTC](https://forum.arduino.cc/t/arduino-leonardo-and-ft232rl/1314854/11 "2024-10-25T16:18:23Z")

</div>

I already done that. Take a look on my configuration:

 ![IMG_20241025_171321](https://europe1.discourse-cdn.com/arduino/original/4X/2/8/b/28bca2abaf60ee6bb4a2f20ea00d9ac9bbf8d35a.jpeg)  
I also realise that your FTD swith is in 3V3. I also change mine.

But no data in the other computer. 😔

---

<div class="post-metadata">

**Author:** ![horace](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/horace/32/1014299_2.png) [@horace](https://forum.arduino.cc/u/horace)\
**Post date:** [October 25, 2024, 5:06pm UTC](https://forum.arduino.cc/t/arduino-leonardo-and-ft232rl/1314854/12 "2024-10-25T17:06:56Z")

</div>

> [@brainsold](#):
>
> I also realise that your FTD swith is in 3V3. I also change mine.

_good idea - the Leonardo uses 3.3V logic 5V can damage it_  
EDIT: ignore the above - the Leonardo use 5V logic

> [@brainsold](#):
>
> But no data in the other computer

what software are you using on the other computer?  
I used [teraterm](https://teratermproject.github.io/index-en.html) with the following parameters

 ![image](https://europe1.discourse-cdn.com/arduino/original/4X/1/f/1/1f188154bcf27ba26b350f216667454f4a80272a.png)

note that flow control is NONE - you may need to set/clear RTS etc depending on your serial software

---

<div class="post-metadata">

**Author:** ![brainsold](https://avatars.discourse-cdn.com/v4/letter/b/919ad9/32.png) [@brainsold](https://forum.arduino.cc/u/brainsold)\
**Post date:** [October 30, 2024, 4:06pm UTC](https://forum.arduino.cc/t/arduino-leonardo-and-ft232rl/1314854/13 "2024-10-30T16:06:43Z")

</div>

Hello Horace,

Many thanks and sorry for the late reply.  
I already can send data to other computer, thanks to you.

Regards,  
Pedro

---

<div class="post-metadata">

**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\
**Post date:** [April 28, 2025, 4:06pm UTC](https://forum.arduino.cc/t/arduino-leonardo-and-ft232rl/1314854/14 "2025-04-28T16:06:46Z")

</div>

Closed on April 28, 2025, 4:06pm UTC

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.