Real-time 'stopwatch' 2012-09-10

This is a simple electronic "stopwatch" you can use to time an event. I used it when developing a device that needed to accurately measure a time interval (a camera shutter-speed tester). I used this to check the accuracy of the project, using a microcontroller (the SX-28).

Pretty simple, really. The first 74HCT4040 counter generates the clock (I used a 1 MHz oscillator and "tapped" the counter at Q7: you can choose these settings to suit your particular needs). The AND gates are used to...

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