Using the AD7091r-2 and I want to have it sequence between chan 0 and 1 all the time.
How do I configurate that to happen?
You can select channels for inclusion in the sequence by setting it's corresponding bit to 1 in the Channel Register described in Table 13 and 14 of the AD7091R-2 datasheet.
Thanks, I understand that, but I want to know for each conversion in the sequence do I send ‘0’ on the sdi to read, or do I just send the convst strobe
and the sdo reports the channel and data as it sequences…??
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Yes, the include the channel ID and 12-bit conv. Conversion results register map is described in Tables 11 and 12 of the datasheet. You just need to provide the /CONVST signal. Please see Figure 55, in your case write 0x03 to the channel register and the sequence cycles through both enabled channels.
Thanks I will try it…
It seems I must write into the channel reg a 0x0C03?? Is this right?
I have tried to send only 0x03, no reg address, but nothing happens.
Am I missing something????
Then I have to give it a CONVST and a CS.
BUTTT it seems only after the first reset it kind of works, from then on resets just give bad results.
IS the MSB bit coming out first on the SDO line??
Do it send the MSB first on the SDI line??
I have matched the timing values on Figure 4.
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We had a network failure and I may not have received your response...
Yes, you must write 0x0C03 as per the write command configuration on page 31 of the datasheet. That table should also answer your question about the order of the bits on the SDI line (yes, MSB first). As well, the SDO line is MSB first, more info on conversion results map I mentioned in my previous post.
I am not sure I understand the problem on reset. Are you doing a device reset via the digital pin or is it software reset? Please send some scope shots of what you are seeing so I can understand this better.
I found out that one has to keep SDI=0 when not writing to the unit, seems work better.
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