Member #150158

Member Since: September 8, 2010

Country: United States

  • If you want to use this with Raspberry Pi, Gordon over at has added maxdetect support to his wiringpi arsenal. I got this working today fairly easily with that.

    Here is the quick program. Make sure to compile with something like "gcc rht.c -o rht -lwiringPi -lwiringPiDev"

    Also note that I had to take out the chevrons in the #include lines for some reason to get those headers to show up

    #include wiringPi.h
    #include maxdetect.h
    #include stdio.h
    #include stdlib.h
    #include stdint.h
    #include time.h
    int main() {
      int myTemp        = 0;
      int myRelHumidity = 0;
      int attempts      = 5;
      int goodReading   = 0;
      if (wiringPiSetup () == -1) {
        printf("\n\nERR: setup for wiringPi failed\n\n");
        exit (1);
      while (!goodReading && (attempts-- > 0)) {
        if (readRHT03 (15, &myTemp, &myRelHumidity) 
          //keep looping and try again
        } else {
          goodReading = 1; // stop now that it worked
      printf("Temp: %2.1fF  ",(((((float)myTemp/10)*9)/5)+32));
      printf("RH: %2.1f%%\n",((float)myRelHumidity/10));
      return 0;
  • Hi,
    So I have been using this cable with my Fio, and I just noticed with this plugged in the 3v3 pin on shows 5 volts. Is that a problem? I see above that it mentions this cable won't damage Arduino Pro, which is also 3v3 for vcc, right? Is the 3v3 mainly just important for the level on the rx/tx lines?

No public wish lists :(