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Unable to get data out on ADAS1000 SPI pin

Question asked by praveen_ardent on Dec 3, 2013
Latest reply on Jan 13, 2014 by Padraic

I am currently using a dsPIC33FJ128MC802 on a DM300027 (starter) board to read data from the ADAS1000SDZ evaluation board via the J4 SPI pins. I have the SPI pins (SCLK, MOSI, MISO and CS) of both boards connected correctly according to the ADAS1k documentation.

 

I am having trouble getting the two (ADAS1k and dsPIC) to talk to each other. I set up the uProc's SPI and then try to configure the ADAS1k by sending 0x8500000B, 0x88F8000D, 0x8B000008, 0x8A079610, 0x81D800AE, 0x40000000 to it, based on Example 4 in the ADAS1k documentation.

These commands should configure the ADAS1k to send out a 150Hz Test Tone Sine Wave on each channel.

The MOSI is enveloped by a CS, and it is sent as 4 bytes, for example 0x8500000B is sent as 0x85 followed by 0x00, 0x00, 0x0B.

 

To read data on the MISO, the SPI sends out four 0x00 bytes to generate clock signals for the MISO.

 

Writing 0x55555555 followed by 0xAAAAAAAA shows a signal on the MISO, which looks like a 0x0050. I haven't been able to get signals on MISO in other cases. I tried writing to a register and reading it back after a few ms delay, but nothing showed up on the MISO. 

 

Any suggestions? Thank you.

 

20131202-0005 (Write555555+WriteAAAAAA)_09.jpg20131202-0005 (Write555555+WriteAAAAAA)_10.jpg

SCLK, CS, MOSI, MISO

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