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vanderbiltrobotics / loadcell

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Beaglebone blue gpio is not fast enough for load cell communication #10

Open AWatk opened 6 years ago

AWatk commented 6 years ago

Unfortunately since the hx711 is trying to be as efficient as possible and only use two lines, the low power mode functionality is interfering with communication using the blue. If the clock is brought high for more than 60 uS, the board goes into low power mode.

http://codeandlife.com/2016/04/18/beaglebone-black-gpio-benchmark/

Per this benchmark, the best switching frequency the blue can get is about 5.5 kHz, which corresponds to a high pulse width of 180 uS

AWatk commented 6 years ago

A somewhat tedious but seemingly straightforward solution is to rebuild the blue with the hx711 driver enabled

http://www.bootembedded.com/beagle-bone-black/hx711-with-beaglebone-black/