Since this change concerns new ticker driver for NRF51_DK it goas on ticker feature branch.
On this branch us ticker is based on 1 MHz higher precision counter (on master is based on 32kHz RTC). As a result of using higher precision counter measurement error increased:
:485::FAIL: Expected 1.060000 Was 1.070478
For delay 1060 ms we measured ~1070 ms so we have about ~1% measurement error which is not bed for this board.
To make it work with 1MHz us ticker increase test tolerance. Define tolerance as follows:
tolerance = 500us + 0.02 * delay.
These boards will be re-enabled when sleep driver for them is ready.
Note:
This operation is done by removing "SLEEP" feature from target's "device_has" list (in targets.json config file).
For NRF52_DK removing of "SLEEP" feature causes some timing issues which have influence on tests. In order to successfully disable this board we need to disable also related features like "USTICKER", "LOWPOERTIMER" and slightly modify ticker tests, so they will not be executed if usticker support is not available (by default all targets support us ticker).