Using a pair of Arduinos to mimic a keyboard

September 28, 2013 / 3 Comments

Here’s a video:

So in my last post I showed you a way that I used a single arduino to talk to a Raspberry Pi (or any other computer) over HID. I’ve updated the project a bit and now I can input any number of things into the pi. Basically this is how it works.

Serial Console on computer -> Arduino Mega -> software serial port -> Arduino micro -> HID on other second computer (in this case the Pi)

There are two buttons that handle pressing the enter key and the delete key as those are hard to send over serial.

There are a few bits of relevant code, both for the arduino. Here’s the mega’s code:

int sent_led = 44;
int test_button = 30;

byte inread;

#include &lt;SoftwareSerial.h&gt;
SoftwareSerial SoftSerial(34, 36); // RX, TX

void setup(){
  pinMode(sent_led, OUTPUT);
  pinMode(test_button, INPUT);

  Serial.begin(9600);
  SoftSerial.begin(4800);

  SoftSerial.println("Hello, world?");

}

void loop(){
  if (Serial.available()&gt;0){
    digitalWrite(sent_led, HIGH);
    Serial.print("Sending: ");
    inread = Serial.read();
    Serial.write(inread);
    SoftSerial.write(inread);
    Serial.print(" , ");
    Serial.print(inread);
    Serial.println("");
    digitalWrite(sent_led, LOW);
  }

}

int sent_led = 44;

int test_button = 30;

byte inread;

#include <SoftwareSerial.h>

SoftwareSerial SoftSerial(34, 36); // RX, TX

void setup(){

pinMode(sent_led, OUTPUT);

pinMode(test_button, INPUT);

Serial.begin(9600);

SoftSerial.begin(4800);

SoftSerial.println("Hello, world?");

}

void loop(){

if (Serial.available()>0){

digitalWrite(sent_led, HIGH);

Serial.print("Sending: ");

inread = Serial.read();

Serial.write(inread);

SoftSerial.write(inread);

Serial.print(" , ");

Serial.print(inread);

Serial.println("");

digitalWrite(sent_led, LOW);

}

And here’s the side for the arduino micro, that writes as an HID.

int stat_led = 3;
int enter_led = 4;
int delete_led = 5;

int enter_button = 6;
int delete_button = 7;
int engage_switch = 8;

#include <SoftwareSerial.h>
SoftwareSerial SoftSerial(11, 10); // RX, TX

void setup(){
pinMode(enter_led, OUTPUT);
pinMode(delete_led, OUTPUT);
pinMode(stat_led, OUTPUT);

pinMode(enter_button, INPUT);
pinMode(delete_button, INPUT);
pinMode(engage_switch, INPUT);

Serial.begin(9600);
SoftSerial.begin(4800);

Keyboard.begin(); //

}

void loop(){
if (SoftSerial.available()){
digitalWrite(stat_led, HIGH);
Keyboard.write(SoftSerial.read());
digitalWrite(stat_led, LOW);
}

if (digitalRead(enter_button) == HIGH){
Keyboard.press(KEY_RETURN);
delay(100);
Keyboard.release(KEY_RETURN);
digitalWrite(enter_led, HIGH);
}
else if (digitalRead(enter_button) == LOW){
digitalWrite(enter_led, LOW);
}

if (digitalRead(delete_button) == HIGH){
digitalWrite(delete_led, HIGH);
Keyboard.press(KEY_BACKSPACE);
delay(100);
Keyboard.release(KEY_BACKSPACE);
}
else if (digitalRead(delete_button) == LOW){
digitalWrite(delete_led, LOW);
}

}

int stat_led = 3;

int enter_led = 4;

int delete_led = 5;

int enter_button = 6;

int delete_button = 7;

int engage_switch = 8;

#include <SoftwareSerial.h>

SoftwareSerial SoftSerial(11, 10); // RX, TX

void setup(){

pinMode(enter_led, OUTPUT);

pinMode(delete_led, OUTPUT);

pinMode(stat_led, OUTPUT);

pinMode(enter_button, INPUT);

pinMode(delete_button, INPUT);

pinMode(engage_switch, INPUT);

Serial.begin(9600);

SoftSerial.begin(4800);

Keyboard.begin(); //

}

void loop(){

if (SoftSerial.available()){

digitalWrite(stat_led, HIGH);

Keyboard.write(SoftSerial.read());

digitalWrite(stat_led, LOW);

}

if (digitalRead(enter_button) == HIGH){

Keyboard.press(KEY_RETURN);

delay(100);

Keyboard.release(KEY_RETURN);

digitalWrite(enter_led, HIGH);

}

else if (digitalRead(enter_button) == LOW){

digitalWrite(enter_led, LOW);

}

if (digitalRead(delete_button) == HIGH){

digitalWrite(delete_led, HIGH);

Keyboard.press(KEY_BACKSPACE);

delay(100);

Keyboard.release(KEY_BACKSPACE);

}

else if (digitalRead(delete_button) == LOW){

digitalWrite(delete_led, LOW);

}

Hey! This post was written a long time ago, but I'm leaving it up on the off-chance it may help someone. Proceed with caution. It may not be a good idea to blindly integrate this code or work into your project, but instead use it as a starting point.

Using Arduino Micro as a USB keyboard for Raspberry Pi

September 16, 2013 / 5 Comments

Greetings from WPI! Here’s a video:

Desperate times call for desperate measures. I recently found out that a club at my school is essentially a hackerspace equipped with 3D printers so I could finally print enclosures for the PiPlanter and the DSFU. But that means I would need to finial the designs for both of them. I needed to find a way to interface with this thing here. So being the idiot that I am, I forgot a USB keyboard, I forgot an analog video cable, I forgot a monitor for the pi and forgot to update the Pi to the latest Raspian build.

What I did bring was an Easy Cap Capture Card in addition to my standard idea-kit which among other things consists of an Arduino Micro, some buttons, some resistors, and wire.

Essentially all I needed to do was connect the Pi to the EasyCap, and be able to send 4 different phrases to it over the keyboard. I needed to be able to send ‘pi’,’password’ (not my actual password), ‘ifconfig’ and enter. I realized that I could easily send this data to the Pi via the Micro as it has the Keyboard. functions built in.

As you can see in the video it worked! And I’m kind of stunned that it did. I can now SSH into the Pi.

Here’s the code for the Arduino:

int uname = 3;
int pass = 4;
int command = 5;
int enter = 6;

int green = 7;
int red = 8;

void setup(){
  pinMode(3, INPUT);
  pinMode(4, INPUT);
  pinMode(5, INPUT);
  pinMode(6, INPUT);

  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);

  Serial.begin(9600);

  Keyboard.begin();
}

void loop(){
  if (digitalRead(uname) == HIGH){
    Serial.print("1");
    Keyboard.print("pi");
    digitalWrite(green, HIGH);
    digitalWrite(red, LOW);
    delay(1000);
  }
  else {
    Serial.print("0");
    digitalWrite(green, LOW);
    digitalWrite(red, HIGH);
  }

  Serial.print(",");

  if (digitalRead(pass) == HIGH){
    Serial.print("1");
    Keyboard.print("password");
    digitalWrite(green, HIGH);
    digitalWrite(red, LOW);
    delay(1000);
  }
  else {
    Serial.print("0");
    digitalWrite(green, LOW);
    digitalWrite(red, HIGH);
  }

  Serial.print(",");

  if (digitalRead(command) == HIGH){
    Serial.print("1");
    Keyboard.print("ifconfig");
    digitalWrite(green, HIGH);
    digitalWrite(red, LOW);
    delay(1000);
  }
  else {
    Serial.print("0");
    digitalWrite(green, LOW);
    digitalWrite(red, HIGH);
  }

  Serial.print(",");

  if (digitalRead(enter) == HIGH){
    Serial.print("1");
    Keyboard.press(KEY_RETURN);
    delay(10);
    Keyboard.releaseAll();
    digitalWrite(green, HIGH);
    digitalWrite(red, LOW);
    delay(1000);
  }
  else {
    Serial.print("0");
    digitalWrite(green, LOW);
    digitalWrite(red, HIGH);
  }

  Serial.println("");
  delay(10);
}

int uname = 3;

int pass = 4;

int command = 5;

int enter = 6;

int green = 7;

int red = 8;

void setup(){

pinMode(3, INPUT);

pinMode(4, INPUT);

pinMode(5, INPUT);

pinMode(6, INPUT);

pinMode(7, OUTPUT);

pinMode(8, OUTPUT);

Serial.begin(9600);

Keyboard.begin();

}

void loop(){

if (digitalRead(uname) == HIGH){

Serial.print("1");

Keyboard.print("pi");

digitalWrite(green, HIGH);

digitalWrite(red, LOW);

delay(1000);

}

else {

Serial.print("0");

digitalWrite(green, LOW);

digitalWrite(red, HIGH);

}

Serial.print(",");

if (digitalRead(pass) == HIGH){

Serial.print("1");

Keyboard.print("password");

digitalWrite(green, HIGH);

digitalWrite(red, LOW);

delay(1000);

}

else {

Serial.print("0");

digitalWrite(green, LOW);

digitalWrite(red, HIGH);

}

Serial.print(",");

if (digitalRead(command) == HIGH){

Serial.print("1");

Keyboard.print("ifconfig");

digitalWrite(green, HIGH);

digitalWrite(red, LOW);

delay(1000);

}

else {

Serial.print("0");

digitalWrite(green, LOW);

digitalWrite(red, HIGH);

}

Serial.print(",");

if (digitalRead(enter) == HIGH){

Serial.print("1");

Keyboard.press(KEY_RETURN);

delay(10);

Keyboard.releaseAll();

digitalWrite(green, HIGH);

digitalWrite(red, LOW);

delay(1000);

}

else {

Serial.print("0");

digitalWrite(green, LOW);

digitalWrite(red, HIGH);

}

Serial.println("");

delay(10);

}

Thanks for Reading!

PiPlanter | Goals and changes

September 3, 2013 / 1 Comment

So I am 151 miles away from the PiPlanter. But thanks to the internet, modern day routers, and wifi dongles I can pretty much control everything about it from here.

That being said, there are a few things I would like to change about the project. First of all, the program itself needs to be more modular. Reason being is that the core program should never stop running, even if changes need to be made. I should be able to screen the main program once, and then never have to stop it ever. This would be advantageous in a few ways but the main example is that the plants will require more water as they get larger, and then less once they start yielding fruit. I could script this, but I think that it would be best to be able to edit the ‘ontime’ value from the program without having to stop the whole process.

I’ll keep y’all posted as I try to implement this.

esologic

Month: September 2013

Using a pair of Arduinos to mimic a keyboard

Using Arduino Micro as a USB keyboard for Raspberry Pi

PiPlanter | Goals and changes