Having trouble sending a string via I2C - c++

Question

I have an arduino with 3 sensors connected and need to send the information I'm getting from the said sensors to another arduino and have it displayed on a connected lcd. I tried to go about this by changing the float values I'm getting into a string, sending the string to the other arduino and displaying that on the lcd. But when I try to execute this, I get an error saying :
" In function 'void receiveEvent(int)':
16:24: error: incompatible types in assignment of int to char [7] "
#include <Wire.h>
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);
int sensePin = A0;
int sensorInput;
int lightPin = A1;
int lightInput;
int gasPin = A2;
int gasInput;
int buzzer = 13;
int b_state = 3;
float temp;
float light;
char t_buffer[7];
int state = 0;
void setup()
{
Wire.begin();
pinMode(A0, INPUT);
pinMode(A1,INPUT);
pinMode(buzzer, OUTPUT);
pinMode(A2, INPUT);
pinMode(buzzer, OUTPUT);
pinMode(b_state, INPUT_PULLUP);
Serial.begin(9600);
lcd.begin(16, 2);
attachInterrupt(digitalPinToInterrupt(3), buttons, FALLING);
}
void loop()
{
gasInput = analogRead(gasPin);
sensorInput = analogRead(sensePin);
lightInput = analogRead(lightPin);
temp = (float)sensorInput / 1024;
temp = temp * 5;
temp = temp - 0.498;
temp = temp * 100;
light = ((float)lightInput - 26) / 8.97;
dtostrf(temp, 6, 2, t_buffer);
Serial.print("Current Temperature: ");
Serial.println(temp);
Serial.print("Current Light: ");
Serial.println(light);
Serial.print("Gas (conc.?): ");
Serial.println(gasInput);
Wire.beginTransmission(9);
Wire.write(t_buffer, 7);
Wire.endTransmission();
delay(100);
if (state == 0){
lcd.setCursor(0, 0);
lcd.print("Temp (C): ");
lcd.setCursor(0,1);
lcd.print(t_buffer);
}
else {
lcd.setCursor(0,0);
lcd.print("Light Intensity: ");
lcd.setCursor (0,1);
lcd.print(light);
}
if (gasInput > 800)
digitalWrite(buzzer, HIGH);
else
digitalWrite(buzzer, LOW);
}
void buttons()
{
lcd.clear();
state = !state;
}
#include <Wire.h>
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);
float temp;
char t_buffer[7];
void setup() {
Serial.begin(9600);
lcd.begin(16, 2);
Wire.begin(9);
Wire.onReceive(receiveEvent);
}
void receiveEvent(int bytes) {
t_buffer = Wire.read();
//temp = t_buffer.toFloat();
}
void loop() {
lcd.setCursor(0, 0);
lcd.print("Temp (C): ");
lcd.setCursor(0,1);
lcd.print(t_buffer);
}
Also I have 2 separate float values that I need to send and I'm thinking I could time the transmissions properly and send them both one after the other. Is this a good way of doing this or is there an alternative way?
The circuit

Answer 1

This may not be a direct answer to your question but it may help you figure it out.
t_buffer is a pointer, while t_buffer[0] is the first character in your buffer. The Wire.read returns a char and not a pointer.
If the explanation above does not make sense you may want to read on arrays.
Having said that, since you main loop is almost empty you can use the suggestion by Juraj and use Wire.readBytes(t_buffer , bytes) this way you do not have to worry about indexing through the buffer.
I would strongly suggest that you put text data in t_buffer and test your application before trying to send a float.