The ADC Pi Plus is an 8 channel 17 bit analogue to digital converter designed to work with the Raspberry Pi. The ADC Pi Plus is based on two Microchip MCP3424 A/D converters each containing 4 analogue inputs.  The MCP3424 is a delta-sigma A/D converter with low noise differential inputs.

Note:
Disconnect the ADC Pi Plus from the Raspberry Pi before changing the address pins.  You may need to short the 5V and ground with a resistor to discharge the capacitors in order for the new addresses to be recognised.

I²C Address Table

Adr 0	Adr 1	I2C Address
Low or Float	Low or Float	0x68
Low	Float	0x69
Low	High	0x6A
Float	Low	0x6B
High	Low	0x6C
High	Float	0x6D
High	High	0x6E
Float	High	0x6F

Recommended Address Configurations

Configuration 1:

Analogue Channels 1-4 = I2C Address: 0x68
Analogue Channels 5-8 = I2C Address: 0x69

Configuration 2:

Analogue Channels 1-4 = I2C Address: 0x6A
Analogue Channels 5-8 = I2C Address: 0x6B

Configuration 3:

Analogue Channels 1-4 = I2C Address: 0x6C
Analogue Channels 5-8 = I2C Address: 0x6D

Configuration 4:

Analogue Channels 1-4 = I2C Address: 0x6E
Analogue Channels 5-8 = I2C Address: 0x6F

Datasheets

MCP3424

Features

• 8 x 17-bit 0 to 5V Single Ended Inputs
• Control via the Raspberry Pi I2C port
• Stack up to 4 ADC Pi V2 boards on a single Raspberry Pi
• Jumper selectable I2C addresses
• Buffered 5V I2C port
• Based on the MCP3424 from Microchip Technologies Inc
• Single Ended full-scale range of 5.0V
• On-board 2.048V reference voltage (Accuracy  ± 0.05%, Drift: 15 ppm/°C)
• On-Board Programmable Gain Amplifier (PGA): Gains of 1, 2, 4 or 8
• Programmable Data Rate Options:
     - 3.75 SPS (17 bits)
     - 15 SPS (15 bits)
     - 60 SPS (13 bits)
     - 240 SPS (11 bits)
• One-Shot or Continuous Conversion Options

Input Ratings & Specifications

Spec	Rating
Vdd (5V pin on I2C bus)	5.0V
All AD inputs and outputs	VSS–0.4V to VDD+0.4 V
Current at Input Pins	±2 mA
I2C SDA/SCL voltage	5.0 V
I2C port current	100 mA

Click to download schematic PDF.

Assembly Instructions

The ADC Pi Plus is supplied with the 40 pin GPIO connector and the 12 pin address connector unsoldered. 

Before using the ADC Pi Plus you will need to solder both connectors onto the PCB.  We suggest soldering the 40 pin GPIO connector first and then the address select connector.  Soldering the address select connector first will make it difficult to access the three corner pins on the GPIO connector.

Watch the assembly video, best viewed in 1080p high quality mode:

PCB Header Assembly Jig

Download and print our PCB Header Assembly Jig to hold your circuit board when soldering the header pins.

Mechanical Drawings

Click image to enlarge

Code Libraries and Demos

We have Python, Arduino, C, C++, Node.js and Windows 10 IOT libraries available for this expansion board.  You can download all of the libraries from github at:

https://github.com/abelectronicsuk/ or click on the logos below for your selected programming language,

Tutorials

We have a range of tutorials for the ADC Pi and ADC Pi Plus in our Knowledge Base

ADC Pi Plus Tutorials

Legacy ADC Pi Versions

See our KB article for previous versions of this board