rasdaq is a client and server code for Raspberry Pi 2 to acquire ADC Data from MCP8208 12-bit ADC converter chip. The SPI interface is emulated using Raspberry PI's GPIO pin, the way that is described in this tutorial. An alternative would be to use raspberry pi's processor's own SPI interface, which is not applied here in this code. The underlying messaging is accomplished using Zero MQ library in PUB/SUB mode.
The code consists of a separate parts:
rdcliis the command line interface (CLI) for client and serverrdguiis just a GUI client (viewer) for visual inspection written in QT5 (PyQt5).
Follow the description on the tutorial mentioned above. Additionally what has been changed here is the following pin numbering:
| Name | Pin No. |
|---|---|
| SCLK | 18 |
| MISO | 23 |
| MOSI | 24 |
| CS | 25 |
As you can see, an additional LED is connected to the raspberry with a 330 ohm resistor in between.
It is recommended to download the full raspbian version, since the full python is included, from here. You can check the shasum before installation to make sure it is the original file.
Later you can use dd to copy the image. The procedure on OSX would be e.g.: Identify the name of the SD Card:
diskutil list
in my case it was /dev/disk2. The unmount it:
diskutil unmountDisk /dev/disk2
then use the dd to copy:
sudo dd bs=1m if=2015-11-21-raspbian-jessie.img of=/dev/rdiskN
you can use ctrl-T to check the progress. After booting if you have a HDMI television and keyboard attached then you can see your IP address of course, but if you like me are only connected to internet without any display then you need to find out the IP address just by connecting to a router. Open router's own web page and find out the IP or MAC address. There are also other methods available under linux.
After the first boot, you need to install a couple of things for the server part. Please note, that you do not need to install PyQt5 or any other GUI elements on the Raspberry PI, as these are only needed for the GUI on the client machine (OSX, Win, Lin, etc...).
sudo apt-get install python3-pip
sudo update-alternatives --install /usr/bin/python python /usr/bin/python3.4 2
sudo update-alternatives --install /usr/bin/pip pip /usr/bin/pip-3.2 2
sudo pip install RPi.GPIO
sudo pip install pyzmq
From then on you can connect using SSH and screen:
ssh -t pi@IP_ADDRESS screen -D -R
The defulat username and password should be pi and raspberry.
You can run the server on the raspberry by:
./rd_server
and accordingly the client by:
./rdgui_gasjet
Many thanks goes to carlkl for pointing out the wonderful ZeroMQ library and Erik Bartmann for the good Tutorial.