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[on:]

I'm ultimately trying to read the ADS1232 with the Arduino for a scale project.  The ADS1232 is a great chip to use for this application as it is basically designed for scales and other sensitive bridge applications that require a lot of increments for a good resolution in output.

I am a beginner in using SPI, so I am trying to follow an example to start.  This one here seems to be the closest out there: http://dangerousprototypes.com/forum/viewtopic.php?f=2&t=4247&p=42053#p42051 however, the output doesn't seem to make sense.  I can tell there is some conditioning for the specific application, but when I apply low amounts of weight, the output will slightly decrease, then jump to increasing values and increase respectively to the amount of weight applied.  I have iterated with adjusting various lines in the code to see if I can get a more linear result, but have yet to be successful.

The data sheet for the ADS1232 http://www.ti.com/lit/ds/sbas350f/sbas350f.pdf definitely divulges the requirements for proper operation such as clocking and so on, even a specific scale application example, but modeling my circuit after this and using the example code, I just can't seem to output a linear decimal result.  I have a feeling the ADS isn't being clocked right, but I really don't understand or know how to ensure this.  Page 19 in the datasheet discusses Data Retrieval.

Anyone have experience here that can help?  I'm literally only trying to output a decimal answer from the ADS1232 to convert into a weight...

Thanks in advance!

[Reply #1 on:]

To add, important wire connections between the Arduino and ADS1232 are as follows:

ADS DRDY/DOUT <----> Arduino Pin 12 (MISO)
ADS SCLK <-------------> Arduino Pin 13 (SCK)
ADS PDWN <------------> Arduino Pin 10 (SS)

These are the only 3 connections for SPI I can see on the ADS1232.

[Reply #2 on:]

These are the only 3 connections for SPI I can see on the ADS1232.

Plus a ground, presumably.

[Reply #3 on:]

Anyone have experience here that can help?

It looks to be fairly conventional, per the datasheet.

Unless you show your code, it is hard to help you.

[Reply #4 on:]

See this topic for a similar chip:

http://arduino.cc/forum/index.php/topic,128823.0.html

[Reply #5 on:]

See this topic for a similar chip:

http://arduino.cc/forum/index.php/topic,128823.0.html

Spot on my friend!  Perfect example.  I modified the details to fit my setup and it works great.  Thanks a lot!  Interesting part is the SPI library isn't even used, but it outputs great numbers!