Building bbPool

The needs

As for poolDuino, I want to measure :

  • water pH, ORP and temperature
  • air temperature

and report that on my emoncms web site.

The hardware

Connecting temperature sensors to the BBB…

and reading the values…

Information for those two temp sensors can be found here for DS18B20 and here for AtlasScientific ones.

Connecting pH and ORP sensor

AtlasScientific pH and ORP stamps are using simple asynchronous serial communication protocol. For communicating with them, we will use 2 of the 4 UARTS available on the Beaglebone, UART1 & 4.

P1040843

Enabling UARTS

First, you need to enable UARTs 1 & 4. That’s easy :

Yeah… I know, but that’s easier like that : don’t need to type sudo before each command. But keep in mind you are root and you can destroy your Ubuntu. So think before you type !

Here, we can see UARTs are not enabled. So let’s enable them.

Reading from UART

I am a perl fan… so I’ll show a perl example, no python as I don’t know python and there is a handfull of examples using python…

I used Device::SerialPort library which is quite handy.

Code is here on GitHub. This code sets pH stamp in continuous reading and reads output every second.

Conclusion

I now have a Beaglebone connected to 2 temperature sensors, an ORP and a pH stamp, and I can read all those sensors value 🙂

I am working on a web GUI to display the information, send the info to my emoncms website and be able to configure the gizmo. So stay tune !

 

Running Ubuntu on Beaglebone Black

Replacing Angstrom with Ubuntu

I quite struggled with Angstrom :

  • could not install most of needed perl modules
  • could not get sftp to work
  • lot of stuff I am not using running by default (and not sure how to remove it)

Not saying Angström is not a good distro. It is good for discovery and just runs out of the box. It is jus a bit raw for me and I am not used to it.

I finally decided to move to Ubuntu, a linux distribution I know a bit more and which has a wider supporting community.

I found all required information to install Ubuntu here : http://elinux.org/BeagleBoardUbuntu. If I do a short summary :

  • Download the eMMC Ubuntu image here : BBB-eMMC-flasher-ubuntu-13.04-2013-10-08.img.xz
  • Unzip it and dump it to an uSD card (2Gb is ok) using WinDiskImage on windows (or dd on linux)
  • Insert SD card into the BBB
  • Power it on
  • Wait for the 4 leds to be solid (can be long, more that 30 minutes…)
  • Remove power
  • Remove SD card
  • Power again : you’re running on Ubuntu !