Delta-Sigma Pi

£14.99 each (including VAT: £17.99)

The Delta-Sigma Pi is an 8 channel analogue to digital converter designed for use on the Raspberry Pi computer platform. The board is based around the MCP3424 low noise and high accuracy 18 bit delta-sigma analogue to digital converter from Microchip Technology Inc.  A pair of MCP3424 converters are included on the board along with an I2C buffer interface allowing you to connect additional 5V I2C devices to the same bus.

The Delta-Sigma Pi is pin compatible with the the Raspberry Pi model B+.


The I2C address bits are selectable using the on-board jumpers.  The MCP3424 supports up to 8 different I2C addresses so with two A/D converters on each Delta-Sigma Pi you can stack up to 4 Delta-Sigma Pi boards on a single Raspberry Pi giving you 32 ADC inputs.

The MCP3424 contains an on-board 2.048V reference voltage with an input range of ±2.048V differentially (full scale range of 4.096V/PGA).  A programmable Gain Amplifier gives the user a selectable gain of x1, x2, x4 or x8 before the analogue to digital conversion takes place.

The data rate for analogue to digital conversions is 3.75 (18 bit), 15 (16 bit), 60 (14 bit) or 240 (12 bit) samples per second. Data rate and resolution can be configured within software using the I2C interface.


Delta Sigma Pi V2.0 Address Configuration and Specification






Input Ratings & Specifications

Maximum voltage on ADC inputs: ± 2.048V

Maximum current on i2c port: 100mA.


Click to download
Click to download schematic PDF.

Mechanical Drawings

Mechanical Drawing

Click image to enlarge

Sample Code

We have python libraries available for this expansion board.  You can download all of the libraries from github at:

To download the libraries to your Raspberry Pi type in terminal:

git clone


The datasheet for the Deta Sigma Pi version 1 can be downloaded here

Product Code: DELTAV1

Copyright © AB Electronics UK 2014 | AB Electronics UK is a trading name of Apexweb Ltd