I am using the PSoC 1 CY29466 MCU. I discovered the internal ADC do not have enough resolution or linearity  for my project. I decided to use ADS1211 ADC. It takes a three wire SPI interface. Can you point me in a direction for examples to write and read from the external ADC?

Thank You,

Philip

 Hello Philip,

I agree that the ADC provided does not have good resolution and it introduces some offset but there are a few app notes available which employees a technique called Correlated Double Sampling (CDS) to measure the signal. App not available here: http://www.cypress.com/?rID=2894 explains that method in detail with an example of how to measure signal of a thermocouple, where resolution required is as low as 40uV.

If you want some code examples for SPI then let me know your email address, I shall be able to send you the projects.

Best regards,

Pushek

I would love help on SPI code. I spent the weekend looking for SPI code to a ADS1211 ADC. I received some nice responses and some responses that should be put in the nasty list. If I can make the 13 bit linear that would be great. I will eventualy need to solve the SPI code problem.

Thank You,

Philip

Would it be very difficult to creat a SPI code and .h file to communicate with the TI ADS1211?

Thank You,

Philip

I did look at the app note. It would not open. It complained about a cmx problem. I opened the main.C file. Even if I could get my 13 bit AD working with 0% error. The best I could acheive would be +/- .0006. This is marginal. My custumer wants x.xxx. So I am forced into using a high accuracy ADC IC. Do you have any sampls of SPI code talking to ADCS? I am stumped on the SPI code.

Thanks

Philip