Usb CncPlayer	Usb CncPlayer	Usb CncPlayer
There is an interesting Usb controller board family available on the market called Arduino. I choose the Arduino Duemilanove, aka 2k9 and ordered some equipment and spare parts.	In order to make the handling of the board a bit more convenient I also ordered a piggy-back board which is called a shield in the Arduino terminology. I thought having a board with screw terminal would be nice.	The shield comes as a kit and I had to assemble and solder it which is a pretty easy task.

Usb CncPlayer	Usb CncPlayer	Usb CncPlayer
This is the controller board and attached on top is the shield with the screw terminal. As you can see it is pretty small. The microprocessor board itself comes fully assembled so nothing to do here. The board is equipped with an Atmel AVR ATmega328p microprocessor.	Same image but I rotated the board a little bit. On the left you can see the Usb connector. The board is powered simply by usb cable. No need to deal with an external power supply (but can be used optional).	Now it's getting a bit weird. On the Arduino board is a small reset button but once you put the shield on top you can't operate it any longer because the button is fully covered.

Usb CncPlayer	Usb CncPlayer	Usb CncPlayer
So what to do? There are several solutions but I opted for a pure mechanical one. I drilled a 6 mm hole in the shield, used a 2.5 mm nail and a spare part from a bycicle's front brake. It looks like a M6 bolt but got a 3 mm drilled hole inside. On a bike this bolt is used to adjust the lash or tension of the front brake's Bowden cable.	The difficult part was to drill the 6 mm hole at the very right position. Surprisingly everything fitted perfectly. I just had to cut off the nail and grind it a little bit. The reset button extender doesn't look very well but works like a charm. Design follows function ;)	Here we are almost done. This is my custom tailored test equipment for the moment. The board's controller has a bootloader. This means that programming the firmware is simply done via the usb cable. No external programmer/burner is required. The wires seen in the image still need to be connected to the shield. Instead of plugging the cnc machine into the PC's lpt port the cnc machine is now plugged into this 25 pin connector.

• So what is this all about? Well, I'm going to port the CncPlayer Client Cpc software to this usb microcontroller which I will call Usb CncPlayer.
• Can I buy the Usb CncPlayer? No, because the firmware is still under development. I estimate that only 40% of the programming work is done as of today. So 60% of the work is still ahead of me.
• Do I need the Usb CncPlayer hardware for the CncPlayer software? No. This board is just a future optional accessory.
• I already bought the CncPlayer software. Can I upgrade my version once the Usb CncPlayer is available? Yes. I'll offer an inexpensive upgrade plan.
• When will the Usb CncPlayer board be available? Frankly, I have no idea at the moment because I'm still in an early development stage.
• Do you use the Arduino ide for programming? No. I use the Atmel AVR studio and a C compiler. The Arduino ide is great but I wanted to have the firmware code to be as portable as possible. Maybe later I'll replace the Duemilanove board by a board with more I/O and more RAM or switch over to a PIC. Not yet sure where it will end.
• How many I/O got the Arduino Duemilanove? 14. That means we can have XYZC stepper motors = 4 * 2 = 8 pins. Then 4 homing switches = 4 pins. And finally one pin for spindle and one pin for coolant = 2 pins. So 8 + 4 + 2 makes 14 pins total. That's almost the same what a PC's lpt port offers and that's pretty well for most hobbyist's cnc job needs. You can also redefine unused pins, btw.

Neue CncPlayer Projekte:

Projekt 1: Unterstützung externer USB Cnc Controller

Geplant, und teilweise auch schon ein bisschen eingebaut, ist der Support für folgende Controller. Die Reihenfolge in der Liste ist rein zufällig und stellt keine Wertung dar:

Diese 3 Bilder zeigen den DeskCnc Controller (Nr. 1 in obiger Liste), den ein Anwender auf eine Einschubplatine für sein Zollgehäuse montiert hat. Dank an R. für die freundliche Leihgabe der Bilder:

Projekt 2: Umbau eines alten A3 Flachbett-Plotters zum Schneidplotter

Die eingebaute Elektronik des Plotters versteht nur ein heute nicht mehr gebräuchliches Protokoll. Also raus mit dieser Elektronik und durch eine normale Schrittmotor-Elektronik ersetzen und mit dem CncPlayer ansteuern. So ist es zumindest gedacht. Wir werden sehen, ob es auch so funktioniert.

Das gute an diesen alten Plottern ist, daß sie relativ groß, relativ stabil und sehr billig sind, weil die meisten Leute sie nicht mehr nutzen können (da veraltetes Protokoll und Schnittstelle). Für Low-Budget Cnc Anwender ist das die Gelegenheit, viel Mechanik zum Taschengeldpreis zu erwerben.

Weitere Infos zum Plotter-Umbau je nach Baufortschritt.