AD7730BNZ python Library

by Atticus on Thu May 16, 2013 8:51 pm

Hi guys,
While this chip isn't sold by Adafruit, almost every other part of my project has been, and I'm getting desperate looking for a library for this chip.

I don't have the required skill set to write up a library myself, I've tried reading through the datasheet, and using analog devices website for help, but I've got myself no where. I've never done anything with an spi interface before. Has anyone here used this chip or a similar 24bit ADC before? If so could you share you code? If not I would be willing to offer incentives for anyone who could look up the datasheet and write me a basic functional library for it.

Some background on the project.

I have a breakout bench with a pair of load cells previously fitted to it. When I acquired the machine, the computer attached to the load cells was gone. The company that fitted the load cells wants around $15,000.00 for a replacement computer (I really don't have that sort of spare change for a PC :-O ) so I've got myself a raspberry pi, LCD shield, pi cobbler wifi dongle etc etc and and thought I'd have a go at it myself. Unfortunately the only ADC I had handy was the ADS1015 breakout, 12bits just aren't enough. I basically see it as on or off, if I'm lucky to see anything at all. After looking around I've found the AD7730BNZ from analog devices, looks perfect for my needs. 24bit ADC bundled up in a dip package specifically for reading from load cells. Only catch is it's SPI and I've only ever worked with adafruits i2c devices in python.

I dont' need it to read fast, bit banging would probably be fast enough, but I've been trying to use the SPI-py package with hardware spi, I get numbers out of the chip but I dont' know what to do with them. And it's confusing the hell out of me.

Any help here would be appreciated.
Posts: 14
Joined: Sat Dec 15, 2012 10:05 pm

Re: AD7730BNZ python Library

by adafruit_support_mike on Fri May 17, 2013 4:52 pm

This is probably something you'll want to post on the Jobs board.
When you void a product warranty, you give up your right to sue the manufacturer if something goes wrong and accept full responsibility for whatever happens next. And then you truly own the product.
User avatar
Posts: 7029
Joined: Thu Feb 11, 2010 1:51 pm

Re: AD7730BNZ python Library

by Atticus on Sat May 18, 2013 10:55 am

Sorry Mike, I can't find a board called jobs?
Posts: 14
Joined: Sat Dec 15, 2012 10:05 pm

Re: AD7730BNZ python Library

by tastewar on Sun May 19, 2013 8:46 am

Look along the top menu bar for the Jobs link, or go to
Posts: 300
Joined: Thu Mar 17, 2011 9:16 am