Optimize UART read for lighthouse #1308
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This PR reduces the CPU load when using the lighthouse system by optimizing the process of reading from the UART.
The current implementation works by using a queue that is filled from an interrupt, triggered when one more byte is available on the UART. The lighthouse task is removing bytes from the queue when reading the next frame and is locking on the queue to get the next byte as soon as possible. This locking (and task switching?) seems to take a long time. This PR uses a
vTaskDelay()in a loop to make sure there are enough data in the buffer before reading to avoid the queue lock.With 4 base stations received CPU load for the LH taks goes down from 21% to 6%.
By increasing the time in the
vTaskDelay()to 2, the CPU load goes down one or two % more, but it also adds a delay.