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Styx shield

What is Styx ?



Styx is a shield allowing to use original Arduino shields with Jaluino. This is an intermediate shield to make two different worlds talk together.

There's no magic behind this shield: pins from Jaluino PIC are arbitrarily mapped against pins from Arduino Atmega. Not all pins can be mapped. For instance, Atmel has often more PWM pins than PIC and, on the contrary, PIC often has more ADC channels than Atmega. So this arbitrarily mapping isn't perfect, but hopefully optimized and usable...

Note: Shield name, "Styx", comes from river Styx (or sometime his guardian) acting as a boundary between Earth and the Underworld. Reader may choose, from Microchip and Atmel, which is Earth and which is Underworld... See http://en.wikipedia.org/wiki/Styx for more information.

Schematic and PCB

Styx schematic is simple, it's just about mapping pins together...

Figure 1. Jaluino Styx schematic

While schematic is simple, PCB is more complex, despite the small number of components... Remember not using this image to build your PCB, as it may not be scaled correctly. This image is just here to give an overview. You can access 1:1 scale Styx PCB and labels, PDF format, on Jaluino SVN repository.

Figure 2. Jaluino Styx PCB

Building Styx

Since PCB looks more complex than one would think, Styx shield isn't so easy to build. You'll have to be careful with thin tracks. Styx is about plugging shield together, so also give attention while soldering pin headers: make sure they are as vertical with the board, and parallel between them, as possible. Else you'll get troubles while plugging Arduino shields.

Styx shield is more a mechanical challenge than an electronic one...

Figure 3. Styx plugged on Jaluino

Figure 4. Side view of Styx plugged on Jaluino. Pin headers on the left aren't perfectly vertical, making Arduino shields not easy to plug.

Using Styx

Using Styx is easy: just plug an Arduino shield on it... The challenge will be to find an Arduino shield compatible with PIC specifications. Theoretically, you could plug any Arduino shields. In practice, prototyping shields are good candidates, due to very simple electronics.

Figure 5. Jaluino, Styx and an original Arduino prototyping shield



Figure 6. Looks like Pise tower...

Figure 7. LED is blinking. Sweet...

Other more complex shields, even if usable with a PIC, will require you to write the program to drive it. If you're in the process of such a challenge, please keep inform us at Jaluino Group1 !

Limitations

Styx shield allows to use Arduino shields. To be accurate, it allows to physically plug Arduino shields. Due to the resulting "Pise design", you may encounter problems when dealing with analog and PWM signals2. Using complex Arduino shields (ie. not prototyping boards as previously shown) may require lots of work to adapt it, writing program on the PIC side.

These limitations obsviously exist. But fun is unlimited :)

1 Jaluino Group can be reached at: http://groups.google.com/group/jaluino