VirtualWire library fights with LiquidCrystal library

Using Arduino Project Guidance
1

So, I FINALY learned how to send a float value over VirtualWire. I have an ATtiny85 with a thermistor and 433 Mhz TX. That reads the thermistor, converts it, averages 5 readings over 1 second, and transmits the data. I am using an ATtiny84 for the RX end of this. Using an LCD and 433 Mhz RX. While using VirtualWire.h and LiquidCrystal.h the LCD does not work. If i comment out the VW setup stuff in "void setup()" the LCD works. I read this, [SOLVED] I can have VirtualWire OR LCD running, not both. - Networking, Protocols, and Devices - Arduino Forum but this didn't help me. I declared my pins and have no overlapping pins. I am not sure what the issue is? Thank you in advance for help.

TX Code:

//THE THERMISTOR IS A 10K THERMISTOR
//                                          DIAGRAM
//  GROUND-----------10K RESISTOR-----------INPUT A7-----------10K THERMISTOR-----------5V

#include <VirtualWire.h>

int Thermostat = A1;
float ThermostatReading = 0;
float Res = 0;

float TempK = 0;    //Tempature in K
float TempC = 0;    //Tempature in C
float TempF = 0;    //Tempature in F
float L1 = 0;
float L2 = 0;
float L3 = 0;
float L4 = 0;
float L5 = 0;
float AvgK = 0;
int Avg = 1;        //Average the temp

char Temp[7];

void setup()
{
  //Serial.begin(9600);
  // Initialise the IO and ISR
  vw_set_tx_pin(0);          //Setting up the transmitter pin
  //vw_set_ptt_inverted(true); // Required for DR3100
  vw_setup(2000);            // Bits per sec
}

void loop()
{
  //Get the Thermistor resistance
  Res = analogRead(Thermostat);
  Res = 1023 / Res - 1;
  Res = 10000 / Res;

  //Calculate the Temp
  ThermostatReading = analogRead(Thermostat);
  TempK = log(10000.0 * (1024.0 / ThermostatReading - 1));
  TempK = 1 / (0.001129148 + (0.000234125 + (0.0000000876741 * TempK * TempK)) * TempK);

  //Average the Readings
  if (Avg == 1)
  {
    L1 = TempK;
  }
  if (Avg == 2)
  {
    L2 = TempK;
  }
  if (Avg == 3)
  {
    L3 = TempK;
  }
  if (Avg == 4)
  {
    L4 = TempK;
  }
  if (Avg == 5)
  {
    L5 = TempK;
    AvgK = (L1 + L2 + L3 + L4 + L5);
    AvgK = (AvgK / 5);
    TempC = AvgK - 273.15;
    TempF = TempC * 1.8 + 32;
    dtostrf(TempF, 6, 2, Temp);
    //Serial.println(Temp);
    vw_send((uint8_t *)Temp, strlen(Temp));
    vw_wait_tx();
    Avg = 1;
  }
  if (Avg <= 0 || Avg >= 6)
  {
    Avg = 1;
  }
  Avg = Avg + 1;
  delay(200);
}

RX Code:

#include <VirtualWire.h>
#include <LiquidCrystal.h>
LiquidCrystal lcd(0, 1, 2, 3, 4, 5);
const int ValBL = 85;     //Value for BackLight Brightness
const int BackLight = 6;  //BackLight PWM Output
int TempF;
char Temp[10];
int i;

void setup()
{
  //Serial.begin(9600);
  pinMode(BackLight, OUTPUT);
  lcd.begin(16, 2);
  analogWrite(BackLight, ValBL);
  // Initialise the IO and ISR
  vw_set_rx_pin(8);
  vw_setup(2000);   // Bits per sec
  vw_rx_start();       // Start the receiver PLL running
}

void loop()
{
  uint8_t buf[VW_MAX_MESSAGE_LEN];
  uint8_t buflen = VW_MAX_MESSAGE_LEN;

  if (vw_get_message(buf, &buflen))
  {
    for (i = 0; i < buflen; i++)
    {
      Temp[i] = buf[i];
    }
    lcd.clear();
    lcd.setCursor(1,0);
    lcd.print("TEMPERATURE");
    lcd.setCursor(2, 1);
    lcd.print(Temp);
    lcd.print((char)223);
    lcd.print("F");
    //Serial.print("char: ");
    //Serial.println(Temp);
  }
}
2

It is just possible that Vitual Wire is entirely innocent, and isn't fighting anybody. The real problem may be because you have LCD on the serial port. I'm surprised you can even upload the RX code. I assume you did so with the LCD disconnected.

As things are, you are calling for the serial port but not using it. You may be able to fix the problem by deleting the redundant Serial.begin, and thereby prove the point. If that works, you might note that using pins 0,1 for LCD would be a particularly dumb habit to get into.

3

Nick_Pyner:
It is just possible that Vitual Wire is entirely innocent, and isn't fighting anybody. The real problem may be because you have LCD on the serial port. I'm surprised you can even upload the RX code. I assume you did so with the LCD disconnected.

As things are, you are calling for the serial port but not using it. You may be able to fix the problem by deleting the redundant Serial.begin, and thereby prove the point. If that works, you might note that using pins 0,1 for LCD would be a particularly dumb habit to get into.

"Serial.begin" is commented out. So I don't believe that is the problem. I am using a sparkfun tiny usb programmer with a shield I made to go from 8 pin dip to 14 pin dip. If I removed the virtual wire code from void setup the lcd works.

4

I swaped pins on the ATtiny84 RX. I made the 433Mhz RX module on pin 0, and changed the lcd from (0, 1, 2, 3, 4, 5) to (2,3, 4, 5, 9, 10). The LCD still will not work?

RX Code:

#include <VirtualWire.h>
#include <LiquidCrystal.h>
LiquidCrystal lcd(2, 3, 4, 5, 9, 10);
const int ValBL = 85;     //Value for BackLight Brightness
const int BackLight = 6;  //BackLight PWM Output
int TempF;
char Temp[10];
int i;

void setup()
{
  //Serial.begin(9600);
  pinMode(BackLight, OUTPUT);
  lcd.begin(16, 2);
  analogWrite(BackLight, ValBL);
  // Initialise the IO and ISR
  vw_set_rx_pin(0);
  vw_setup(2000);   // Bits per sec
  vw_rx_start();       // Start the receiver PLL running
}

void loop()
{
  uint8_t buf[VW_MAX_MESSAGE_LEN];
  uint8_t buflen = VW_MAX_MESSAGE_LEN;

  if (vw_get_message(buf, &buflen))
  {
    for (i = 0; i < buflen; i++)
    {
      Temp[i] = buf[i];
    }
    lcd.clear();
    lcd.setCursor(1,0);
    lcd.print("TEMPERATURE");
    lcd.setCursor(2, 1);
    lcd.print(Temp);
    lcd.print((char)223);
    lcd.print("F");
    //Serial.print("char: ");
    //Serial.println(Temp);
  }
}