Control esp32 via keyboard keys

Question

I'm making a project in which I have to control a mini car and get sensor information via bluetooth. I'd like to be able to control the mini car with the computers keyboard (w,a,s,d), but I was not able to find a library that could help with that, like the "keyboard" library does in python for example

Ex.

import keyboard
# when w is pressed, the car goes forward
If (keyboard.is_pressed("w"):
 Forward()

The "keyboard" library in arduino does not seem to work the same way. And I didn't find any other libraries nor tutorials about it online.

How to make it work?

Answer 1

In case someone is trying to do the same, I came up with a way to make it work. In ArduinoIDE, after the setup, the loop checks if the bluetooth serial is available and has received anything, if it receives the right variables for movement, it passes the instruction to the motors connected to the Arduino through an l298n module.

The code is as follows:

// variáveis para conexão bluetooth // variables for bluetooth connection
#include <SoftwareSerial.h>
SoftwareSerial SerialBT(8, 9);
char valorDoBluetooth;
//variáveis para o uso dos motores // variables for the use of motors
// motor 1
const byte in1 = 2;
const byte in2 = 4;
const byte enA = 3;
//motor 2
const byte in3 = 5;
const byte in4 = 7;
const byte enB = 6;
int velocidade = 100; // motor speed (up to 255)
int componentesOut[6] = { in1, in2, enA, in3, in4, enB }; // list created to setup the variables more easily
void setup() {
 SerialBT.begin(9600);
 Serial.begin(9600);
 // loop to set pins to Output
 for (int n = 0; n < 6; n++) {
 pinMode(componentesOut[n], OUTPUT);
 }
}
void loop() {
 // Read data from the Bluetooth module
 if (SerialBT.available()) {
 valorDoBluetooth = SerialBT.read(); // bluetooth Value
 if (valorDoBluetooth == 'F' || valorDoBluetooth == 'T' || valorDoBluetooth == 'D' || valorDoBluetooth == 'E' || valorDoBluetooth == 'P') // if SerialBt recieved movement value
 {
 movimento(); // movement
 }
 }
}
void movimento() {
 if (valorDoBluetooth == 'F') {
 Serial.println("Frente"); // Forward
 frente();
 } else if (valorDoBluetooth == 'T') {
 Serial.println("Trás"); // Backwards
 tras();
 } else if (valorDoBluetooth == 'D') {
 Serial.println("Direita"); // Right
 direita();
 } else if (valorDoBluetooth == 'E') {
 Serial.println("Esquerda"); // Left
 esquerda();
 } else if (valorDoBluetooth == 'P') {
 Serial.println("Parar"); // Stop
 parar();
 }
 delay(1);
}
void frente() {
 digitalWrite(in1, HIGH);
 digitalWrite(in2, LOW);
 digitalWrite(enA, velocidade);
 digitalWrite(in3, LOW);
 digitalWrite(in4, HIGH);
 digitalWrite(enB, velocidade);
}
void tras() {
 digitalWrite(in1, LOW);
 digitalWrite(in2, HIGH);
 digitalWrite(enA, velocidade);
 digitalWrite(in3, HIGH);
 digitalWrite(in4, LOW);
 digitalWrite(enB, velocidade);
}
void direita() {
 digitalWrite(in1, LOW);
 digitalWrite(in2, HIGH);
 digitalWrite(enA, velocidade);
 digitalWrite(in3, LOW);
 digitalWrite(in4, HIGH);
 digitalWrite(enB, velocidade);
}
void esquerda() {
 digitalWrite(in1, HIGH);
 digitalWrite(in2, LOW);
 digitalWrite(enA, velocidade);
 digitalWrite(in3, HIGH);
 digitalWrite(in4, LOW);
 digitalWrite(enB, velocidade);
}
void parar() {
 digitalWrite(in1, LOW);
 digitalWrite(in2, LOW);
 digitalWrite(enA, velocidade);
 digitalWrite(in3, LOW);
 digitalWrite(in4, LOW);
 digitalWrite(enB, velocidade);
}

To be able to control it via the PC keyboards, I connected the PC to the device through bluetooth, then see which COM it is connected to in bluetooth configurations of control panel, and use this the COM number on a Python code that's able to communicate with the device.

The Python code is as follows:

import serial
import time
import keyboard
# Replace 'COMX' with the actual COM port assigned to the HC-05 module / Esp device on your PC. More info at https://pyserial.readthedocs.io/en/latest/shortintro.html
ser = serial.Serial('COM8', 9600, timeout=1)
flagMovido = True # flag that checks if the motors are finished moving before changing directions
def controle(event):
 global flagMovido
 if event.event_type == keyboard.KEY_DOWN: # if a key is pressed:
 if (event.name == "w" or event.name == "a" or event.name == "s" or event.name == "d") and flagMovido: # if movement keys are pressed and motors are finished moving to any other direction:
 flagMovido = False # motors started moving
 if event.name == "w" and not flagMovido:
 ser.write(b'F')
 print('frente') # Forward
 elif event.name == "a" and not flagMovido:
 ser.write(b'E')
 print('esquerda') # Left
 elif event.name == "s" and not flagMovido:
 ser.write(b'T')
 print('trás') # Backwards
 elif event.name == "d" and not flagMovido:
 ser.write(b'D')
 print('direita') # Right
 elif event.event_type == keyboard.KEY_UP: # if a key is released:
 if (event.name == "w" or event.name == "a" or event.name == "s" or event.name == "d") and not flagMovido: # if movement keys are released and motors are moving to some direction
 flagMovido = True # motors are finished moving
 ser.write(b'P')
 print('parado') # Stop
print('START')
def main():
 while True:
 data = ser.readline().decode().strip()
 keyboard.hook(controle)
 time.sleep(.001)
 if data:
 print(f"Recebido: {data}") # prints data if any received. Used to print the sensor values received.
if __name__ == "__main__":
 main()

obs:

• The code runs fine, but may present some problems if you press to many keys at a time, since it was made to handle one direction at a time. But the movement bools will help with that and prevents it from happening to certain extent. Though in specific cases is should be improved.
• I ended up using a HC05 module with Arduino, but the code also woks for Esp. But if connecting to an Esp, the ser = serial.Serial('COM8', 9600, timeout=1) line should be changed to the way it connects to the Esp. More info at the link provided.

• jsotola: it is good to see that you were able to figure this out yourself ... the test of all values in loop() is somewhat redundant, just call movimento() without an if statement
• Matrodsilver: Thanks, and good point. I narrowed down the code to explain the logic here, but in the project I'm making this 'if' statement is actually necessary. That's true nonetheless, as it is, that's just a unnecessary 'if' statement.