Delta-Sigma Pi
Created 11/05/2016 | 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 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 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.
Datasheets
Delta Sigma Pi V2.0 Address Configuration and Specification
BSN20
MCP3424
Input Ratings & Specifications
Maximum voltage on ADC inputs: ± 2.048V
Maximum current on i2c port: 100mA.
Schematic
Click to download schematic PDF.
Mechanical Drawings
Click image to enlarge
Sample Code
We have Arduino, C, Windows 10 IOT, Python 2 and Python 3 libraries 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 terminal:
git clone https://github.com/abelectronicsuk/ABElectronics_C_Libraries.git
To download the Python 2 libraries to your Raspberry Pi type in terminal:
git clone https://github.com/abelectronicsuk/ABElectronics_Python_Libraries.git
To download the Python 3 libraries to your Raspberry Pi type in 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
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