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| Top-bottom: frequency update, data, clock |
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| First data byte magnified - 8 clock pulses send 00000011 |
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| Arduino 'Uno' board and logic analyser connected |
I have a new toy to play with; the Saleae 24MHz 8 channel logic analyser. Looking for some signals to analyse with it, I programmed my Arduino board's SPI ( serial peripheral interface ) pins, incorporating the appropriate library code, to send frequency update pulses, 4MHz clock and 6 bytes of data to an AD9850 DDS chip. I was unsure how the SPI modes had been implemented in the library code. With the logic analyser connected I was quickly able to determine where my own code required modification so that the desired signals were obtained.
I needed 3 of the 8 available channels of the logic analyser. Previously I would have had to use my dual channel oscilloscope, viewing only 2 signals at once.
