feb08 シリアル通信検証

sketch_feb07a.ino

float f = 100;
float amp = 255;

void setup() {
//  pinMode(A0, OUTPUT);
  Serial.begin(115200);
}

void loop() {
  float t = (float) millis() / 1000;
  float value = (1.0 + sin(t * f * (2.0*PI))) / 2.0;

  analogWrite(A0, (int) (value*amp));
  
  float output = analogRead(A1);
  Serial.println(output);
}

sketch_feb08a.ino

#include <TimerOne.h>

unsigned char buffer[1500];
int buffer_size = sizeof buffer;
int buffer_write_ptr = 0;
int buffer_read_ptr = 0;
bool first_data = true;

void setup() {
  for (int i=0; i<buffer_size; i++) buffer[i] = 0;

  Serial.begin(115200);

  Timer1.initialize(1.0/500 * 1000*1000);
  Timer1.attachInterrupt(readNextAmp);
}
void readNextAmp() {
  int value = buffer[buffer_read_ptr];
  analogWrite(A0, value);
  buffer_read_ptr += 1;
  if (buffer_read_ptr > buffer_size) {
    buffer_read_ptr = 0;
  }
}

void loop() {
  int value = Serial.read();
  first_data = value >= 0;
  if (! first_data) {
    value = 0;
  }

  if (value < 0) value = 0;
  buffer[buffer_write_ptr] = value;
  
  buffer_write_ptr += 1;
  if (buffer_write_ptr > buffer_size) {
    buffer_write_ptr = 0;
  }

  Serial.print(micros());
  Serial.print(",");
  Serial.print(buffer_read_ptr);
  Serial.print(",");
  Serial.print(buffer_write_ptr);
  Serial.println();
}