I have an 'Eval-AD7793' board and trying to interact through SPI interface.
After configuring the channel, callibrated zero and full scale, and set mode to continuous conversion, single reads sequences are executed perfectly (as in figure18, AD7793 DataSheet):
Send 8 CLKs: 0x58 [Read operation for Data Register]
Send 24 CLKs: 0xFFFFFF [Generate 24 CLKs to let AD7793 set current Data Register value]
This process of reading values is the one implemented in AD7793 Evaluation Software
What I need is the process described in figure 19, AD7793 DataSheet: Continuous Read
When sending 8 CLKs: 0x5C [Continuous Read operation for Data Register]
I see DOUT/RDYn signal going high and low (high for 800us, as stated in )
--- Attatched capture trigger point (see below) ---
When sending 24CLKs: 0xFFFFFF [Generate 24 CLKs to let AD7793 set current Data Register value]
The first conversion is correct
But next conversions (started on falling edge of DOUT/RDYn) don't show similar values to first one.
The second conversion has 8 CLKs with '1's and '0's and the rest 16 CLKs all '1's.
The rest of conversions have a first part of all '0's and a second part of all '1's...
Attatched is a capture of signals:
before sending the first 24CLK block (as noted before)
Each vertical black line separates a consecutive capture
Trigger fires on Rise edge of SCLK
SCLK is about 520kHz, 50% duty
Please, can you help me find a clue to make continuous read work?
Thanks in advance,