I have a pair of 434MHZ from Sparkfun. I am using the virtualwire library and am using them to send temperature data and the number of bubbles going through a photo interrupter attached to my homebrew beer fermenting away.
When I was sending just temperature data fairly often, I got great range. Now that I am sending information once every minute or so, my range seems to have decreased. I think I am having problems with the auto gain I have read about on these receiver ICs. Any ideas how to correct? I could add an additional loop to my while statement and transmit more often than once a minute, but how often should I transmit? Thanks!
#include <VirtualWire.h>
int ledPin = 13; // LED connected to digital pin 13
int photoPin = 2; //
int bubblePin = 12;
int val = 0;
int tempPin = 5; // lm34 analog pin
int tempF=0; // temperature
int transPin = 9; // transmit pin
unsigned long start;
unsigned long totalCount = 0;
unsigned long currentCount = 0;
void setup()
{
pinMode(ledPin, OUTPUT); // sets the digital pin as output
pinMode(photoPin, INPUT);
pinMode(bubblePin, OUTPUT);
Serial.begin(9600); // Debugging only
Serial.println("setup");
// Initialize virtual wire stuff
vw_set_tx_pin(transPin);
vw_set_ptt_inverted(true); // Required for DR3100
vw_setup(2000); // Bits per sec
}
void loop()
{
start = millis(); // take the start time
//Serial.print("Millis: ");
//Serial.println(start);
currentCount = 0; // reset couter
// do the following loop for 60000ms = 1min
while (millis()-start < 60000)
{
val = digitalRead(photoPin);
if (val==LOW)
{
digitalWrite(bubblePin, LOW);
currentCount ++;
}
else
{
digitalWrite(bubblePin, HIGH);
}
}
// 1 minute over. print conts
currentCount = currentCount/10000; //scale down to bubbles
totalCount = totalCount + currentCount;
//Serial.print("Current count: ");
//Serial.println(currentCount,DEC);
//Serial.print("Total count: ");
//Serial.println(totalCount,DEC);
tempF= ( 5.0 * analogRead(tempPin) * 100.0)/ 1024.0;
//Serial.print("Temperature in Farenheit: ");
//Serial.println(tempF,DEC);
char char_temp_f[4];
char char_bpm[10]; //expect at most 7 characters plus 'bpm' so 10 should be big enough
char char_total[15]; //expect at most 10 char plus 'total' so 15 should be big enough
itoa(tempF,char_temp_f,10);
itoa(currentCount,char_bpm,10);
itoa(totalCount,char_total,10);
strcat(char_temp_f, "F");
strcat(char_bpm, " bpm");
strcat(char_total, " total");
digitalWrite(ledPin, true); // Flash a light to show transmitting
vw_send((uint8_t *)char_temp_f, strlen(char_temp_f));
vw_wait_tx(); // Wait until the whole message is gone
digitalWrite(ledPin, false);
delay(200);
digitalWrite(ledPin, true); // Flash a light to show transmitting
vw_send((uint8_t *)char_bpm, strlen(char_bpm));
vw_wait_tx(); // Wait until the whole message is gone
digitalWrite(ledPin, false);
delay(200);
digitalWrite(ledPin, true); // Flash a light to show transmitting
vw_send((uint8_t *)char_total, strlen(char_total));
vw_wait_tx(); // Wait until the whole message is gone
digitalWrite(ledPin, false);
delay(200);
}