The Graphing Altimeter

If you experience problems compiling the altimeter code, it is because there are conflicts in the libraries used. When you include a library, the code in this library becomes part of your program. If one library names a variable “read8”, for instance, and another library also names a variable with the same name then there is a conflict. I have edited the libraries where there are conflicts to solve this problem.

Here is what to do:

1.       Backup your current libraries. Go to the folder Documents\Arduino\libraries, select all of the folders, right click and select “Send To … compressed (zipped) folder” and name it something like “library backup”. Now delete all of the library folders, but not the zip file that you just created.

2.       You need to remove all of the involved libraries, as the Arduino Editor will look other places for libraries as well. You may need to do the same with the “C:\Program Files (x86)\Arduino\libraries” folder as well.

3.       Download “AltimeterArticleLibraries.zip” to the Documents\Arduino\libraries folder and extract (unzip) it there.

4.       If your Arduino editor pops up a message that says “Some of your libraries are out of date, would you like to update them?”, chose “no” or you will replace the needed edited libraries with ones that will conflict.

The latest version of the code is Altimeter183.

The people who program these libraries cannot anticipate what combinations of libraries will be used in a project, so it is easy to see why this might happen. This makes for a little trouble for you and me, but I applaud their efforts, and am thankful that companies like Adafruit have made these libraries and made them available to use free of charge.

The printed circuit board can be ordered from ExpressPCB with the special mini-board pricing. The mini-board is bigger than needed, so there are lines in the board traces to cut the board to proper size.

My method of extending the tactile switch buttons worked well, and gave nice, tiny little buttons on the front. Another alternative is to use switches that have long buttons on them. Of course, the holes in the front panel need to be bigger. An example of this is DigiKey’s switch EG5455-ND. The footprint on the board is slightly different, and the holes will need to be repositioned.