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11 years, 2 months ago.
i get 0degree out of my temp sensor
Hi, I cannot read anything from the TMP102, i tried with the example code and this gave nothing. I made my own code:
#include "mbed.h"
Serial pc (USBTX, USBRX);
I2C i2c (p9, p10);
const int addr = 0x90;
int main() {
char send[1];
send[0]=0; //sending the pointer adres to temperature register
char ontvangentemp[2]; //want 2 bytes of information in
while(1){
i2c.write(addr, send, 1, 0);
i2c.read(addr, ontvangentemp, 2, 0);
pc.printf("test voor TMP102_nieuw1\n\r");
pc.printf("\n\r the temperatuur is %d , %d", ontvangentemp[0], ontvangentemp[1]);
}
}
The first time i got "test .... the temperatuur is 0, 128), the next times i always get 0,0. how come? i know this will not be the right temperature because i still have to do some conversion Next problem is, most of the time when i push on the button nothing happens in hyperterminal, and then suddenly they come with 10 at the time and i dont see a relation when it happens. anybody has an idea, thanks in advance
2 Answers
11 years, 2 months ago.
Do you have pull - up resistors on SDA & SCK ??
and are the wires the correct way around.
somewhear between 2K2 & 7K5, to 3V3.
I dont have TMP102, so no more advice.
Ceri
11 years, 2 months ago.
Hi,
I have the solution for hyperterminal. You need to flush the stdout everytime you write a printf, otherwise it is printing when the buffer is full of data. Flush is not a member function of pc. But you also don't need the pc infront of a printf. Only for changing the baud rate of pc, there is an explicit call of the member function needed!
Serial pc (USBTX, USBRX); // USB Virtual Serial Port
...
int main()
{
pc.baud(9600); // changing baud
...
printf("Hello World"); // write some characters
fflush(stdout); // flush the stdout
...
error(""); // Blue Lights of Death
...
}
There is also a second solution. End a printf with a \n character. In my opinion this is not a safe solution, but used in the hole mbed world.
fixed
posted by Adriaan Van Steendam 07 Mar 2013