Michael Li sent me the note below about his cool ultrasonic distance sensor that he will be showing at Thursday meetup. Feel free to ask him questions about this project on Thursday.
For Thursday night, I will bring a couple of small demos to entertain our audience. This is an ultrasonic distance sensor. The distance can be determined by measuring the width of the return time pulse from the sensor. This demo shows that the S5D9 board is capable to source 5V supply to the sensor and the MUC IO pin is able to tolerate 5V input signal from the sensor. So, I can connect the 5V sensor to PMOD without using any level shifter chip.