Using arduino uno with honeywell humidity sensor

I'm using an uno with a Honeywell HIH-8120 humidity sensor. They communicate via I2C. I need to put the sensor into "command" mode to modify some settings.

Unfortunately the only way to enter command mode is to send a specific instruction to the sensor within 3ms of it being powered on. I'm not sure if the arduino is able to complete it's boot cycle before the 3ms is up. Checking with my DMM it appears that the rails get powered before the arduino is finished booting.

Anyone know how long the boot time is for the uno? Anyone run into this issue before and find a way around it?

you can use a digitalpin to power the sensor (either directly or through a power transistor and switch the sensor on when you want to.

Thanks! That worked!

Good to hear it worked,
can you post your code (snippet) for future reference?

void setup(void)
{
    Serial.begin(9600);
    Wire.begin();
    pinMode(11, OUTPUT); //Sensor is powered off of pin 11
    analogWrite(11, 255);
    write_word(0xa0, 0x0000);  // Enter command mode within 3ms
}

Hi,

I'm working HIH 8120..
I'm a beginner, so could anyone give me the full final code ?