= high precission ad-da board from waveshare

== intro

image:./pic/high_precission_ad_da_board.png[]

== prereqs

download and flash centos7 on the microSD card

 wget http://mirror.nl.datapacket.com/centos-altarch/7.9.2009/isos/armhfp/CentOS-Userland-7-armv7hl-RaspberryPI-Minimal-4-2009-sda.raw.xz
 zcat CentOS-Userland-7-armv7hl-RaspberryPI-Minimal-4-2009-sda.raw.xz | dd of=/dev/sdb bs="4M" status="progress" iflag="fullblock" oflag="direct"

boot the raspberry with the microSD

 rootfs-expand
 yum -y update
 reboot
 
 yum -y install gcc-c++ make wget
 yum -y install https://armv7.dev.centos.org/repodir/epel-pass-1/p7zip/16.02-10.el7/armv7hl/p7zip-16.02-10.el7.armv7hl.rpm
 
== compile bcm2835 libraries

 wget http://www.airspayce.com/mikem/bcm2835/bcm2835-1.68.tar.gz
 tar xzf bcm2835-1.68.tar.gz
 rm -f bcm2835-1.68.tar.gz
 cd bcm2835-1.68/
 ./configure
 make
 make install
 cd
 
== compile ads1256 sample

 wget https://www.waveshare.com/w/upload/5/5e/High-Precision-AD-DA-Board-Code.7z
 7za x High-Precision-AD-DA-Board-Code.7z
 rm -f High-Precision-AD-DA-Board-Code.7z
 cd ./RaspberryPI/ADS1256/bcm2835/
 make clean
 make
 cd 
 ./RaspberryPI/ADS1256/bcm2835/ads1256_test
 
----
 demo
bcm2835 init success !!! 
ID Read success 
0 2.103088
1 1.121597
2 1.215120
3 1.215360
4 1.215203
5 1.215342
6 1.215304
7 1.215112
----
 
== references

https://www.waveshare.com/

https://www.waveshare.com/high-precision-ad-da-board.htm

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