Getting Started; Digital To Analog Conversion - Waveshare High-Precision AD/DA Board User Manual

High-Precision AD-DA User Manual
2.

Getting started

The following API source codes should be run under the bcm2835 library, which can be downloaded
from http://www.airspayce.com/mikem/bcm2835/
2.1. Analog to digital conversion
1) Connect the High-Precision AD-DA Board to the Raspberry Pi.
2) Jumper settings:
Set the Power Supply to 5V: connect the pin 5V and VCC.
Set the Reference Input Voltage to 5V: connect the pin 5V and VREF.
Set the Potentiometer output as an Analog Input: connect the pin ADJ and AD0. Make sure the
left side Sensor Interface AD0 is disconnected.
Set the LDR output as an Analog Input: connect the pin LDR and AD1. Make sure the left side
Sensor Interface AD1 is disconnected.
Connect AINCOM to AGND. When using AD for differential measurements, the common input
AINCOM does not need to be tied to ground.
3) When using SSH for terminal control, please connect the network cable. The software PuTTY
should be installed. See the section 1.2.
4) Power up.
5) Copy (using a USB drive as a carrier) the software directory, ADS1256, to the Raspbian OS. Note:
the system will detect the USB drive directly under GUI, else if using SSH Connection, the USB
drive cannot be operated until it is mounted to the Linux. Search the key words "Linux mount"
for more details.
6) Make the files:
Enter the directory ADS1256, and execute make to compile it.
Execute sudo ./ads1256_test
7)
Note: if it prompts command not found, please use chmod +x ads1256_test to add
execute permission.
8) Block the LDR from light and then the voltage of channel AD1 will be changed.
9) Turn the potentiometer and the voltage of channel AD0 will be changed.
10) In the end, press Ctrl+C to suspend the current process.

2.2. Digital to analog conversion

1) Connect the High-Precision AD-DA Board to the Raspberry Pi.
Revision: 1.2. Date: October 30 2015. Author: Zhou Jie. Editor: Felix
5