AD7768-1
Recommended for New Designs
The AD7768-1 is a low power, high performance, Σ-Δ analog-to-digital converter (ADC), with a Σ-Δ modulator and digital
filter for precision conversion...
Datasheet
AD7768-1 on Analog.com
LTC2606
Production
The LTC2606/LTC2616/LTC2626 are single 16-, 14- and 12-bit, 2.7V-to-5.5V rail-to-rail voltage output DACs in a 10-lead DFN package. They have built-in...
Datasheet
LTC2606 on Analog.com
Hello!
I recently acquired a CN0540 board and want to use it in my project to measure sensor data from PCB's 393A03 and 393B12 accelerometers. However, I'm using ESP32-S3 microcontrollers, which are not compatible with the board.
The thing is, I don't require much configuration of the board itself, I only wish to measure acceleration with a 200Hz maximum sampling frequency, convert using a 24 bit ADC and store the measurement values in an SD card, so I believe the default settings should do it, but I could be wrong.
Currently, I'm only connecting the ESP32 to the following pins on top of the board:
-3.3V and GROUND
-SPI interface (CS_ADC, DOUT, SDI and SCLK);
-PIN_N/SPI
-RESET_ADC
All the remaining pins, including the ones at the bottom of the board, are disconnected.
I am capable of reading and writing register values from the AD7768-1, but attempting to read the 24 bit data register only results in the value 128.00, even after connecting the sensor via SMA to the CN0540 board, which indicates that it isn't working. Moreover, in the board itself, only two LEDs light up, the FAULT LED (red) and the CC LED (blue). I know that the POWER LED (green) should also be on, but it isn't.
With this in mind, my question is: can I use this method to interface with the CN0540 board and obtain sensor data with 24 bits resolution? If yes, what connections am I missing? If not, is my only alternative buying one of the supported boards?
I hope someone can help me out!
Hi BananzSplit
To answer your main question:
With this in mind, my question is: can I use this method to interface with the CN0540 board and obtain sensor data with 24 bits resolution? If yes, what connections am I missing? If not, is my only alternative buying one of the supported boards?
The connections you have for SPI* are correct, so you will be able to communicate and collect data from the ADC. However, this reference design makes use of a level shifting DAC which subtracts the DC bias voltage of your sensor. Without this sort compensation algorithm which is loadable to the DE10Nano, the sensor signal would saturate the ADC, giving erroneous data. The algorithm itself is not very complicated (successive approximation model, like balancing a seesaw), so if you can have that and communicate with the DAC and ADC, then you get the intended performance. Still, note that the drivers working with the DE10nano controls other parts of the board, so it is still more convenient to have this platform.
*This notes that the 3V3 label you see on the board is actually the "IOREF" node on the schematic. This powers the ADC's SPI communication block, which allows you to communicate with it. But this also means that the actual "3V3" node powering the supply rails is not powered in your setup, which is the reason why the POWER LED is off.
Sorry about the confusion. To power all the supply rails, you can provide 3.3V to the AVDD2 test point or through the Arduino header (P2 pin 4) underneath.
Regards,
Malcolm
