Hey guys

You didn’t hear much from me for a while now, but don’t worry, I’m not gone. I just hadn’t a lot of time because of school. But that doesn’t mean I have nothing for you to show - especially for my b100000000th post

About half a year ago I came across the PIC microcontrollers by Microchip and since I was making a bunch of asm routines at that time, I decided to give them a try. I hooked up the PICkit3 demo board to my 83+ and programmed some routines for serial communication. With the accelerometer ADXL-335z at the AD inputs of the PIC it is even possible to control programs by moving the breadboard around. As power supply I’m using a Nokia BL-5C battery which lasts quite long (1020 mAh) and is relatively light in weight.



Code:


 
Interrupts have to be disabled.

In later versions I used polling to keep sender and receiver in sync, but the delays between the bytes are fixed. Thus, there mustn't be too much code between each GET(). It works quite well for now, but the program might get stuck in more complicated applications. To prevent that, I'm planning to make a closed function for the whole communication process.

This project isn't finished, I showing just early prototypes.

Planned features:

• General purpose functions for axe and pic programmers
• Communication in both ways
• Arbitrary packet length and check sum
• Network applications

Let me know what you think

The all examples with the accelerometer use the same program on the PIC, the programs on the calc are independent and made in axe. The Pic pretty much listens for a request by the TI (when data pin is set to HIGH) and makes a analog to digital conversion of the analog X and the Y values of the ADXL. Those raw values are sent as two bytes to the calc. The calculator subtracts a calibration value (stored at program start) off those bytes, so you get 0 when the board is hold horizontally. The new values function as the speed of the cursor.
But it is indeed a nice idea to write a hook and control the OS with the board.


And no, my last name isn't Gaye

Yeah, I actually thought of making a racing game like Megacar (in case you remember that )

Keoni, there is, we're talking in it right now.

Keoni, there is, we're talking in it right now.

I mean something similar to the games an applications archives/download section.

A wiimote requires some kind of bluetooth tranceiver. A nunchuck however uses I2C which is much easier to interface with.

The TI-interface is coming along nicely, so that might be your first product right here. As for the PIC mcu: It's really easy to port the link protocol. Just change some of the hardware specific stuff like interrupts and ports and you're good to go. Just hooking up accelerometers using I2C is also possible with calculators. The link protocol I wrote is very similar to I2C, so with some modifications a low speed I2C protocol can be implemented in AXE (low as opposed to 100Mb/s)

You can simply run wires from the batteries in your calc to the mcu. That is what I did for my soundchip prototype. Now I just hacked my calculator and put an expansion port on the side that will connect to some I/O of the atmega and power.

Have you guys seen the game Cave Droid for android?  You're going through a cave and there are things that you need to avoid.

If we attach the accelerometer to the calculator then we would be able to make a similar game.  The problem is that only a few people would be able to play it since it would require additional hardware.