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Bynase on the Tiny2313

I put a bynase receiver on my Tiny2313 on the WOSP display board. I found an old source code that didn't work. It took me several hours to figure out how to get the LED driver code working. Now I can display the ramp chip in binary. I can also just put a long wire 'antenna' on the input and watch the lights flash. This could be a reasonable electromagnetic field detector!

But no, it's going to be part of the world's dumbest calculator. I still need to build the keyboard section which will read a bank of 8 switches. The current numeric input goes via bynase to the main processor. The plus and minus switches connect directly to the main processor.

The keyboard won't be a real bynase system because it won't have the pull-up resistors disabled. I'll probably put a switch in that line and a socket where you can plug in real bynase networks (or long-wire antennas). So the system is a dumb calculator but a usable bynase display.

Cybords Rule

... Link

Cybord PWM converter

I've built a cybord to PWM converter. It takes the bynase value on PI and converts it to a PWM signal on OC0A (Tiny13 pin 5). I hope to add the bynase-in code to my Tiny2313 display driver.

The current cyboard part runs at 1MHz on the Tiny13 chip. I'm driving it with the ramp generator I mentioned yesterday. I found that putting an LED on the PO line messed the signal up. Have to use a different pin (there are three more on Tiny13) for monitoring. Right now the PWM output is driving an LED, it goes from dim to bright, but when it goes dim again it sometimes goes dim in two steps instead of one. I suspect there may be a timing issue somewhere.

My PWM converter doesn't have PO at the moment. I should probably add it for completeness. I might try the Dice cybord and connect it to my PWM converter to see how that works.

... Link

When Cybords Attack

Cybords by Ward Cunningham.

I think I might use Bynase in my "World's Dumbest Calculator" project. I don't understand cybords, but I want to. I got the file and built a simple cybord on a Tiny13 chip. I figured a ramp would be a good thing to have, so my first try was as follows:

 inc byout
 rcall byop
 rcall bydle
 rjmp main

I put an LED and a current limiting resistor from PO to ground. Worked like a lead balloon (not at all).

Sat and thought awhile. Part of my problem is I don't understand how to debug these things. Perhaps I should download the pre-defined cybords and see if I can get them working.

After some thought I decided to slow my ramp down. I have a 256 count delay (decrement R17 until it underflows, then decrement byout). Not much better. So I changed it to decrement byout every fourth time through the loop. Now it goes from dim to bright slow enough to watch it. I put the voltmeter on PO and it was going from zero to about half a volt.

Took another look at the specification on Bynase puts a high signal than waits hundreds of counts before repeating. I guess in a way I'm doing a very low-level PWM signal. So the LED lights up but not as much as I want. My next step is to add a second cybord chip that listens to signals on PI and translates the value to a real PWM signal. Have to figure out the settings for the timer to do PWM. Or I could just get the TV output ported to Tiny13. The ValueFilterMeter would help me see what is on the bynase circuit.

Eventually I plan to have a Tiny2313 read the 8-bit input switchbank and send the calculator status on two bynase signals. One for the input number and one for the accumulator. The Tiny2313 already on the display board will read the bynase signals and update the LED outputs.

... Link

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7983 days of detection
mod: 12/3/08, 5:42 AM

days of detection

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Randall Bohn lives in Orem, Utah, USA. He works as a Software Quality Engineer. He is a big fan of the AVR line of microcontrollers. He has been in the computer industry since 1989. Randall is married and has three children.

rsbohn can be reached via

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