__interrupt void irq_handler（ void ）
{
...
// if the hardware interrupt came from the MAX44000 sensor
// pulling its INT pin low
if （ irq_source == MAX44000 ）
{
// if the device is in sleep mode
if （device_status == SLEEP_MODE）
{
device_status = WAKE_MODE; // wake up the device
...
// reconfigure whatever else you need here as the system wakes up
}
// otherwise， handle it however it is you wish
else
{
...
}
}
...
}
/**
* configure_max44000_for_sleep_mode（）
*
* Sets up the MAX44000 to trigger a hardware interrupt when the proximity
* counts go above some set threshold.
*
* Arguments：
* uint8 upper_threshold - the set threshold （8-bit mode）
*
* Returns：
* n/a
*/
void configure_max44000_for_sleep_mode（uint8 upper_threshold）
{
uint8 max44000_thresh_registers［］ = {0x0B，0x0C};
uint8 max44000_upper_thresh［］ = {0x40，0};
max44000_upper_thresh［1］ = upper_threshold;
// do a consecutive write of 0 followed by upper_threshold to
// registers 0xB and 0xC， respectively
// MAX44000_ADDR is usually 0x94
// interrupt will trigger only if proximity value is above the threshold
write_i2c_register（MAX44000_ADDR，max44000_thresh_registers，
max44000_upper_thresh，2）;
// write to bits 2 and 3 of register 0x0A here if you wish to set the
// persist time to anything other than one sample
// writes to register 0x01 to enable interrupts on the MAX44000
max44000_enable_interrupt（）;
return;
}