Pyxis2 and OneWire


I have just included a small working part of code to read a DS18B20 probe (the code example that can be found page 84 of the beginners Guide) in a Pyxis2 project (a .pxe).

The code is included in a Timer called every 2 seconds but looks to crash on the ow.Reset() call (I don’t know exactly as nothing happens - the Pyxis2 gui is still responding).

If I comment the code related to ow, everything works fine (it displays a counter).

Is there something to init at top of the project to activate the OneWire lib? (something that could have been disabled by the Pyxis2 controller?)

I will try to update the EMX firmware to the last release as I spent my four last hours on this problem…

You are having problem when you are adding a GHI library, which means you have a mismatch between your firmware and libraries being used.

If you updated your firmware like you said in other post, then you now have old assemblies being used in your project. Remove all assemblies and add them back to fix the problem

Or start new project and add your old files to it

See this

@ Cugel,

There are a couple of possibilities with this one. It could be a lib that Pyxis doesn’t use and isn’t getting loaded w/ your project; or an AppDomain issue or a bug in Pyxis itself.

The new version is very close to being release (I’m pushing really hard to get it out this week) which cycles through all the .pe files in the application’s folder and loads them into the AppDomain if they’re not already present.

I’ll see if I have anything useful laying around to test out OneWire with to make sure it works for the release.


thank you for your hope about AppDomain. I’m stuck after hours trying to make it work. I even tried with the firmware with all libs updated in my project and Pyxis2 project (see my other post). But no luck… Can’t wait for the next beta!

@ Gus and @ Skewworks. : thanks!

@ cugel,

Since you’re using Pyxis so actively I thought I’d give you a rundown of some of the key additions and changes so you can start planning for them.

New Controls
Filebox (Used for displaying and selecting files from a provided path)
Scrollbar (single control supports both Horizontal & Vertical)

New Features
Launch additional apps from your app.
List all available drives
Auto-select primary drive (Drive w/ Pyxis installed)
Run without a drive (Less certain functionality, obviously)
Prompt (modal: display an alert to the user and get a response OK/Cancel/Yes/No)
Inputbox (modal: gather simple text response from user)
SelectDirectory (modal: returns a selected directory)
Apps run in their own domain
Improved loading of App dependencies
Apps are launched in new threads
Semi-Transparent modal screens

Additional Planned Features
Web Apps
System Settings Window
In-Field Updates

EDIT: Almost forgot we’ve also created an app called “File Finder” which is included in Pyxis and allows you to browse all available drives; manage files; and launch applications.

that’s incredible!

I have programmed some kind of dock (like OSX) (horizontal or vertical) with icons (pictureboxes) to move toward pages (using a different form on each page) in my app. It’s like a tab bar but smarter. I think this is a important GUI element as many apps have a lot of information to display/handle, so they must decomposed in different pages. May be you can add this kind of GUI element in the future?

As I’m a true beginner, I wonder if the documentation could be a little more descriptive about creating an debuggable app. My app is .pxe and I cannot debug it, I just copy it each time on the SD Card to launch it directly from the Pyxis desktop in the FEZ Cobra. I own a second project, a standard NetMF project without any GUI part, to debug the more difficult things (thread, timers, OneWire, etc.).

Again, thanks for your prodigious work!

If you send along the component in question I’ll have a look at it and see about implementing a version in Pyxis. Tabs are something I completely forgot to program in (though with panels & buttons you have everything you need to make your own); perhaps I will put it into the Release Candidate (Beta 2 doesn’t have time for that addition I don’t think).

Debugging an app is a bit difficult. You do have access to the Debug object so you can always do prints from there. Perhaps I’ll see about creating a special project for use with debugging apps…


Pyxis 2 Beta 2 is planned to be released tomorrow night (11/17/2010).

I’ve finished the last of the major work; including In Field Updates and now just need to update the site and documentation.

At the moment WebApps and the Settings Window are [italic]not[/italic] included in the release but that doesn’t mean they won’t make it in. And even if they don’t; that’s what the System Update button is all about.