Hello all,
first of all I opened another thread in the ADC forum here, but since there is almost no activity in comparison to this beautiful lively place I would like to ask for some help in here too.
The original post is placed here: http://e2e.ti.com/support/data_converters/precision_data_converters/f/73/p/233145/821740.aspx#821740
Now to explain the basic things:
I want to use an external ADC with 16 bit, since we got some troubles with the internal 12 bit ADC in the MSP430F5437, which I am using.
I am having a lot of issues not beeing able to correctly get data or recieve data from the ADS8327. Although some functions seem to work, so for example if i am sending 0xD000 to the ADC it will send back some data, which is also related to the voltage I connect at the IN+ pin of the ADS8327.
To make it more clear what is so strange:
My REF+ = 2,5 V
REF- = GND
So I would assume when I measure 0 V I get back 0000 0000 0000 0000, and when measuring 2,5 V or above I will get 1111 1111 1111 1111
What I do see is this:
0 ... 1,25 V -> 0x0000 ... 0xFFFF
1,251 V ... 2,5 V -> 0x0000 ... 0xFFFF
How ever in this world can this be? Am I having troubles with my external reference? I did measure it, although till now only with a handheld multimeter, but it didnt show anything else but 2,5 V so I assume its right, and anyway the behaviour is superstrange I think.
Next thing:
If I send the command for reading the config register 0xC0 I should get back something like 0xFFFD and I always get back 0xFFFE and this simply cannot be true in any world, since one of those bits is coupled to what hardware device it is and since I am using the ADS8327 there is always a 1 in one certain place... so I am really kind of confused.
So since I do not get any further with the trial and error I really would appreciate the help of someone already working with exactly this device and telling me if I am completly off the road, or if I am really close with what I am trying to do.
Thanks for reading and trying to understand my mind :)
Seb