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Precision Sensing using 24-bit isolated ADC (ADE7912)

A project log for evive: a prototyping platform for makers

An open-source Arduino based toolkit to learn, build & debug electronics and robotics projects

Dhrupal R ShahDhrupal R Shah 08/13/2016 at 16:590 Comments

One drawback of ADCs in almost all development boards ranging from Arduino to Pi to Udoo is that its limited to 0 to 5 (or3.3V) and the accuracy is also not very good (~20mV). So we tried to have larger range and selected the Analog devices 24-bit dual channel isolated ADC (Analog to Digital Converter) ADE7912. Its a recently announced precision sensing and measuring IC, which is very fast and works with SPI communication. Its calibrated for range of -30V to +30V on one channel, while the other can be used for current sensing in range of -3A to +3A or voltage sensing in range of -5V to +5V. By isolated ADC, it means that even if the actual potential is like say 48V at some point and 20V at other, still it can work (something like differential ADC). Also the speed is also very fast and one data sample takes ~15us while in Arduino MEGA it takes ~112us. The accuracy is upto 3mV and 3A respectively and working to improve this.

Hence, we can use it like a voltmeter or ammeter or a mini oscilloscope (since we have a TFT screen also)
All the codes are available (opensource) at our Github repository: https://github.com/evivetoolkit/evive/tree/master/testCodes/testGraphingNavKeyADE7912

This video shows the working of evive as a mini oscilloscope (with limited frequency range):

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