C++ / Arduino serial.read to

Question

I 'm trying to send the buffer of the USB HID input (which is always numeric) to the analogwrite function. So i need to convert it to a byte or an integer. Any idea how?

#include <HIDSerial.h>

HIDSerial serial;

unsigned char buffer[32];
ledPin = 10;

void setup() {
  serial.begin();
}

void loop() {
  if(serial.available()) {
    int size = serial.read(buffer);
    if (size!=0) {
      serial.write((const uint8_t*)buffer, size);
      // It will fail cause it needs a conversion from unsigned char to something else..
      analogWrite (ledPin,buffer)
    }
  }
  serial.poll();
}

Answer 1

You can convert a char to a uint8_t like this:

//assume these variables
char thisChar = '9';
uint8_t thisByte;

thisByte |= thisChar;

Serial.println(thisByte, BIN);

The output of this is: 00111001

This works because they are both a single byte variable. You are moving the bits over using a bitwise operation.

Answer 2

Not sure what you are trying to do here.

serial.read() and serial.write() deal with a buffer of data up to 32 bytes long. You can't convert that to an integer in a meaningful way. Also note that buffer is a pointer to the memory where the data is located. It will be the same number every time, so it doesn't make sense to send that.

analogWrite() writes a PWM value from 0 to 255 to a pin. Is this really what you want to do?

Answer 3

Found the solution:

This is the full program:

#include <HIDSerial.h>

HIDSerial serial;

unsigned char buffer[2];

void setup() {
  serial.begin();
}

void loop() {
  if(serial.available()) {
    int size = serial.read(buffer);
    if (size!=0) {
      int bright = atoi((char *) buffer) ;
      analogWrite(0,bright);
      serial.println(bright);

    }
  }
  serial.poll();
}