Hello, Im trying to write some code to control multiple servos (6) using 2 arduinos communicating via 2 Xbees.
I have started by trying to code for a single servo but I'm getting limited movement. The servo only moves from 0-126 deg. I have based my code off the Xbee LED control code on page 202 of the "Making things talk" book.
I would like help determining why the servo is not moving to the full 180deg.
As far as I can tell, the values of 126-180 do not get passed along correctly after the "return message;" command at the bottom of the code.
When I print the "sensorReading" value it goes all the way to 180 but not the "sensorvalue" values.
sorry for the messy coding.
I have the code the same for the send and receive with the exception of changing the xbee addressing.
//======================================
#include <Servo.h>
Servo myservo; // create servo object to control a servo
//=====================================
#define sensorPin 0 // input sensor // analog pin used
#define txLed 2 // LED to indicate outgoing data
#define rxLed 3 // LED to indicate incoming data
#define analogLed 9 // LED that changes brightness with
// incoming value
#define threshold 2 // how much change you need to see on
// the sensor before sending
int lastSensorReading = 0; // previous state of the switch
int inByte= -1; // incoming byte from serial RX
char inString[6]; // string for incoming serial data
//char inString[100]; // string for incoming serial data
int stringPos = 0; // string index counter
void setup() {
// configure serial communications:
Serial.begin(9600);
// configure output pins:
pinMode(txLed, OUTPUT);
pinMode(rxLed, OUTPUT);
pinMode (analogLed, OUTPUT);
// set XBee's destination address:
setDestination();
// blink the TX LED to indicate the main program's about to start:
blink(3);
//==========================================
myservo.attach(8); // attaches the servo on pin 9 to the servo object
//==========================================
}
void setDestination() {
// put the radio in command mode:
Serial.print("+++");
// wait for the radio to respond with "OK\r"
char thisByte = 0;
while (thisByte != '\r') {
if (Serial.available() > 0) {
thisByte = Serial.read();
}
}
//1000 reciver
//1001 sender
// set the destination address, using 16-bit addressing.
// if you're using two radios, one radio's destination
// should be the other radio's MY address, and vice versa:
Serial.print("ATDH0, DL1000\r");
// set my address using 16-bit addressing:
Serial.print("ATMY1001\r");
// set the PAN ID. If you're working in a place where many people
// are using XBees, you should set your own PAN ID distinct
// from other projects.
Serial.print("ATID1111\r");
// put the radio in data mode:
Serial.print("ATCN\r");
}
// Blink the tx LED:
void blink(int howManyTimes) {
for (int i=0; i< howManyTimes; i++) {
digitalWrite(txLed, HIGH);
delay(200);
digitalWrite(txLed, LOW);
delay(200);
}
}
void loop() {
// listen for incoming serial data:
if (Serial.available() > 0) {
// turn on the RX LED whenever you're reading data:
digitalWrite(rxLed, HIGH);
handleSerial();
}
else {
// turn off the receive LED when there's no incoming data:
digitalWrite(rxLed, LOW);
}
// listen to the potentiometer:
char sensorValue = readSensor();
// if there's something to send, send it:
if (sensorValue > 0) {
//light the tx LED to say you're sending:
digitalWrite(txLed, HIGH);
Serial.print(sensorValue, DEC );
//===================================================================
//Serial.print("sensorValue =");
//Serial.print(sensorValue, DEC );
//Serial.println();
//====================================================================
Serial.print("\r");
// turn off the tx LED:
digitalWrite(txLed, LOW);
}
}
void handleSerial() {
inByte = Serial.read();
// save only ASCII numeric characters (ASCII 0 - 9):
if ((inByte >= '0') && (inByte <= '9')){
inString[stringPos] = inByte;
stringPos++;
}
// if you get an ASCII carriage return:
if (inByte == '\r') {
// convert the string to a number:
int brightness = atoi(inString);
// set the analog output LED:
//analogWrite(analogLed, brightness);
//=============================
myservo.write(brightness);
//Serial.print("brightness =");
//Serial.print(brightness);
//Serial.println();
//==============================
// put zeroes in the array
for (int c = 0; c < stringPos; c++) {
inString[c] = 0;
}
// reset the string pointer:
stringPos = 0;
}
}
char readSensor() {
char message = 0;
// read the sensor:
int sensorReading = analogRead(sensorPin);
// look for a change from the last reading
//==================================
// scale it to use it with the servo (value between 0 and 180)
sensorReading = map(sensorReading, 0, 1023, 0, 179);
//=================================
// that's greater than the threshold:
if (abs(sensorReading - lastSensorReading) > threshold) {
//message = sensorReading/4;
//=================================
message = sensorReading;
//Serial.print("sensorReading =");
//Serial.print(sensorReading);
//Serial.println();
//=================================
lastSensorReading = sensorReading;
}
return message;
}
