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en:c1_gpio_pps [2015/08/11 08:10] (current) mdrjr created |
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+ | ====== GPIO PPS Client ====== | ||
+ | In this example I've choose pin #7 to be my PPS input. You can use any other GPIO [[en:c1_hardware#expansion_connectors|Here]]. | ||
+ | |||
+ | |||
+ | == Enabling GPIO PPS Client == | ||
+ | <code> | ||
+ | sudo -s | ||
+ | apt-get install device-tree-compiler pps-tools | ||
+ | fdtput -c /media/boot/meson8b_odroidc.dtb /pps | ||
+ | fdtput -t s /media/boot/meson8b_odroidc.dtb /pps compatible "pps-gpio" | ||
+ | fdtput -t s /media/boot/meson8b_odroidc.dtb /pps gpios "GPIOY_3" | ||
+ | </code> | ||
+ | |||
+ | Reboot the board to test. | ||
+ | |||
+ | |||
+ | == Testing GPIO PPS Client == | ||
+ | Start feeding the signal to the selected pin (#7 in this example). Remember that the logic voltage is 3.3V. | ||
+ | |||
+ | <code> | ||
+ | sudo -s | ||
+ | ppstest /dev/pps0 | ||
+ | </code> | ||
+ | |||
+ | Will output something like: | ||
+ | |||
+ | <code> | ||
+ | source 0 - assert 1439248167.494093618, sequence: 552 - clear 0.000000000, sequence: 0 | ||
+ | source 0 - assert 1439248167.494140618, sequence: 553 - clear 0.000000000, sequence: 0 | ||
+ | </code> | ||
+ | |||
+ | Note this example will only run on kernel 3.10.80-122 or greater. |