2

I want to measure speed with one infra gate. The width of the bypassing object is known therefore I could calculate the speed. However the infrared gate would be interrupted only for 3-10ms. I understand raspi is not real time but it doesn't matter for me as far as I can get the exact time between low-high and high-low.

Improve this question
3

My pigpio library will let you reliably time gpio transitions to within a few microseconds.

The library itself is written in C but you can use any language you want to capture the data (the events are time-stamped at source).

Improve this answer
2
  • Looks promising. I'll give a try. – Andras Csehi Nov 7 '14 at 21:46
  • 3
    @goldilocks That does NOT affect pigpio's time-stamping of gpio events. The gpios are sampled by the hardware DMA engines which are pretty much insulated from system activity. – joan Nov 8 '14 at 17:16

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.