We are having trouble daisy chaining 2 ADS1278 on SPI. We are prototyping our design with two ADS1278 EVM boards. We connect these (in daisy chain) to an STM32 eval board. We are running the ADS in low speed mode, both ADS and SPI clocks are 5.12 MHz. We want to pull 3 channels from the near ADS and 6 from the far ADS. We power down the unused channels and use dynamic format.
We connect same SYNC*, and SCLK to both ADS.
The data gathered in the STM32 from the near ADS is good. The data from the far is not. Our guess is that we may bedropping a bit in the exchange between the far and near ADS. We have checked SCLK shape at each ADS and skew between the two ADS. Skew is less than 1 ns. Shape is good.
Everything we see points to a problem in the Dout \ Din between the ADS's.
Looking for assistance in isolating the problem and getting things to work. Hope to hear from Keith Nicholas!
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