Knowledge Base
The AB Electronics UK Knowledge Base provides support solutions, tutorials and troubleshooting guides.
Delta-Sigma Pi (Discontinued)
Delta-Sigma Pi ADC Board
This item has been replaced with the ADC Differential Pi
Go to the ADC Differential Pi.
The Delta-Sigma Pi is an 8-channel analogue to digital converter designed for 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, and an I2C buffer interface allows you to connect additional 5V I2C devices to the same bus.
The I2C address bits are selectable using the onboard 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 onboard 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 occurs.
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 the software using the I2C interface.
Datasheets
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.
Mechanical Drawings
Click the image to enlarge
Sample Code
Arduino, C, Windows 10 IOT, Python 2 and Python 3 libraries are available for this expansion board. You can download all of the libraries from GitHub at:
https://github.com/abelectronicsuk/
Download the Arduino libraries from: https://github.com/abelectronicsuk/ABElectronics_Arduino_Libraries
To download the C libraries to your Raspberry Pi, type in the terminal:
git clone https://github.com/abelectronicsuk/ABElectronics_C_Libraries.git
To download the Python 2 libraries to your Raspberry Pi, type in the terminal:
git clone https://github.com/abelectronicsuk/ABElectronics_Python_Libraries.git
To download the Python 3 libraries to your Raspberry Pi type in the terminal:
git clone https://github.com/abelectronicsuk/ABElectronics_Python3_Libraries.git
Download the Windows 10 IOT libraries from:https://github.com/abelectronicsuk/ABElectronics_Win10IOT_Libraries/
The datasheet for the Deta Sigma Pi version 1 can be downloaded here.
