Autonomous low-power glare sensing chip

A custom-designed CMOS glare sensing chip is presented that can operate without external control. The chip is a 64×32 pixel focal-plane array that checks periodically for the presence of glare - a light intensity greater than a predefined threshold. If glare is present, the chip wakes up an external microcontroller, which takes control of the chip and reads out the precise glare location. When the microcontroller is done, it returns the chip to autonomous mode and goes back to sleep to save power. Autonomous operation is accomplished using an onboard ring oscillator to generate the control signals. Its small size and very low power consumption in idle and readout modes make it ideally suited to wearable devices.