Raspberry Pi High-Precision AD/DA Expansion Board - Waveshare

Raspberry Pi AD/DA Expansion

Overview

There's no AD/DA function on the Raspberry Pi GPIO interface, this may trouble you in the Pi development. However, it won't be a problem anymore. The High-Precision AD/DA Board allows you to add high-precision AD/DA functions to the Raspberry Pi.

Features

• Standard Raspberry Pi 40PIN GPIO extension header, supports Raspberry Pi series boards, Jetson Nano
• Onboard ADS1256, 8ch 24bit high-precision ADC (4ch differential input), 30ksps sampling rate
• Onboard DAC8552, 2ch 16bit high-precision DAC
• Onboard input interface via pinheaders, for connecting analog signal
  • the pinout is compatible with Waveshare sensor interface standard, easy to connect various analog sensor modules
• Onboard input/output interface via screw terminals, for connecting analog/digital signal
• Features AD/DA detect circuit, easy for signal demonstration

What's on Board

1. Raspberry Pi GPIO interface : for connecting with the Pi
2. AD/DA input/output : screw terminals
3. AD input : pinheaders, the pinout is compatible with Waveshare sensor interface standard, easy to connect various analog sensor modules
4. 7.68M crystal
5. LM285-2.5 : provides reference voltage for the ADC chip
6. Photo resistor
7. LED output indicator
8. 10K potentiometer
9. DAC8552 : 16bit high-precision DAC, 2ch
10. Power indicator
11. ADS1256 : 24bit high-precision ADC, 8ch (4ch differential input)
12. ADC testing jumper
13. DAC testing jumper
14. Power selection jumper
15. ADC reference ground configuration : when AD single inputted, the AINCOM is reference terminal, can be connected to GND or external reference voltage

Interface Definition

Pin	Symbol	Description
1, 17	3.3V	Power supply (3.3V)
2, 4	5V	Power supply (5V)
3, 5, 7, 8, 10, 18, 22, 24, 26, 27, 28, 29, 32, 36, 38, 40	NC	NC
6, 9, 14, 20, 25, 30, 34, 39	GND	Ground
11	DRDY	ADS1256 data ready output, low active
12	RESET	ADS1256 reset input
13	PDWN	ADS1256 sync/power off input, low active
15	CS0	ADS1256 chip select, low active
16	CS1	DAC8552 chip select, low active
19	DIN	SPI data input
21	DOUT	SPI data output
23	SCK	SPI clock
31, 33, 35, 37	GPIO	extend to sensor interface

Photos

High-Precision AD/DA Board back view Connecting with RPi A+ Connecting with RPi2 B Connecting with sensors

Note : the Raspberry Pi and sensors in the photo are NOT included.

Dimension

Development Resources

Wiki : www.waveshare.com/wiki/High-Precision_AD/DA_Board