Weird results with the PWM triggered example.

[jalinei]

@cfoucher-laas This example was no longer working after v1.0.0 update so I fixed it in #51

However I don't get the expected results when flashing the board and testing.
Whatever the voltage applied to pin 30 (actually I only tested shorting it to 3.3V) I get a terminal output like :

7.000000
7.000000
No new value
No new value
9.000000
No new value
9.000000
6.000000
8.000000
8.000000
4.000000
8.000000
7.000000
5.000000
No new value
No new value
5.000000
8.000000

I would like to have you view on that one, so we can figure out if it is actually a bug.

[cfoucher-laas]

There seems to be multiple issues at stake here.

• No new value seems to be related to the coordination between critical task and background task, because calling spin.data.getLatestValue() empties the buffer. It can thus occur that a new call too early provides no new data. The PWM runs at 200 kHz and the critical task every 100 ns (= 10 kHz). Does the PWM trigger an acquisition at every cycle, or less? Because moving the getLatestValue() to the background task (1 Hz) fixes this issue.
• Regarding the value itself, using pin 35 I have the same issue, however it works on pin 34. Are we sure pin 35 is available and not used for something else? Are we sure the example worked prior to 1.0?