Quote:
Originally Posted by ScottishColin
So - I reckon there's c. 2.6 'major' divisions, so 2.6 * 50ms = 130ms. Am I closer?
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Yep. Actually a smidge more than 130mS, call it 131mS.
Now you've got the hang of measuring voltage and time, you can try your hand at another measurement which is traditionally possible with scopes - frequency measurement. I know your scope actually indicates the frequency of the signal which is a nice feature, but you can have a stab at it anyway.
The chip select signal is repetitive, it does the same thing over and over again so it can be said to have a steady frequency. 'Frequency' is the number of repetitions, or 'cycles', in one second.
You are working / measuring in milliseconds so let's stick with those units. There are a thousand milliseconds in one second.
You've already established how long one waveform cycle is - 131mS - by measuring from the start of one waveform cycle to the same point on the next waveform cycle (falling edge to falling edge).
Armed with this information, and given that there are 1000 milliseconds in a second, can you say how many cycles there are in one second? Whatever answer you get, you can check by using the frequency measurement feature of your scope to see how close you were.