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9 years, 7 months ago.
_repClock.read_ms() check
DMU.cpp
while (_repClock.read_ms() < 100); //check to ensure device isn't read more than once every 100 ms
I can't quite understand this line. If we already have _spi->frequency(1150000); why we need to have another check here?
Question relating to:
1 Answer
9 years, 7 months ago.
They are two very different things.
The SPI frequency sets the bit rate when talking to the device.
That while loop is a thousand times slower and is enforcing a minimum time between each read.
Why enforce a minimum time between reads?
Because at the bottom of page 7 of the data sheet it says:
Quote:
Note 2: A quiet time (tq) between messages is required, and 3x( t1 + Tm + Th)+ tq = Ttot. Optimum performance is achieved with a repetition rate of 1ms. Select an appropriate Tclk to meet the requirements of Tm, and then adjust tq to give a Ttot of 1ms.