Keoni29
« on: 12 May, 2012, 13:55:42 »
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I designed this digital to analog converter for use with calculators which lack of sufficient I/O. This is a 4 bit DAC which means that there are 16 possible voltage levels.
What do you think?
Documentation: Operating voltage: 3,3V-5V Data has to be sent in like this: xxxx01 Send data: Least significant first The 01 at the beginning has to be sent in before the 4 bit word. This is due to the architecture of the "timing" circuit. Example: Send 5: 0101 01 For use with calculators: AXE code sample which outputs a sawtooth wave:Spoiler for Hidden :
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.TEST 0->V Repeat Getkey(15) DAC(V If V++ =16 0->V End End 0->port Return Lbl DAC 2->Port //Sends the first two bits indicating the end of a word 3->Port 1->Port 3->Port For (4) //Sends the 4 bit word to the DAC If r1^2 //Part of the dec->bin conversion 2->Port Else 1->Port End 3->Port r1/2->r1 //Part of the dec->bin conversion End
I HAVEN'T BUILT ANYTHING YET, SO I DON'T KNOW WHERETHER IT WORKS OR NOT. THIS IS POTENTIALLY HARMFULL FOR YOUR CALCULATOR, SO STAY AWAY FROM IT UNTILL THE OPPOSITE HAS BEEN PROVEN.Built da thing. Here 's how to make your own:
http://www.omnimaga.org/index.php?action=dlattach;topic=13542.0;attach=13198
« Last Edit: 10 July, 2012, 21:21:45 by Keoni29 »
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aeTIos
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Reply #1 on: 01 June, 2012, 20:45:36 »
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What should the clock speed be?
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If something above sounds rude, feel free to vote it down, it was not meant to be rude<<lolol
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Keoni29
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Reply #2 on: 03 June, 2012, 09:46:38 »
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That will depend on the transfer rate of the calculator. As fast as you can get the software to run
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Keoni29
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Reply #3 on: 08 June, 2012, 13:12:42 »
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I made a new more advanced, but simpeler design which uses less gates
It's made in Logisim, so I think the only one who can open it atm is aeTIos
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aeTIos
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Reply #4 on: 08 June, 2012, 21:57:52 »
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I guess you're wrong, lotsa ppl here know logisim. In fact, I discovered logisim via omni
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If something above sounds rude, feel free to vote it down, it was not meant to be rude<<lolol
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Keoni29
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Reply #5 on: 08 June, 2012, 22:01:36 »
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Oh ok. That's nice!
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ralphdspam
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Reply #6 on: 09 June, 2012, 02:58:07 »
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How about multiplexing it with an ADC as well? I'm not really sure if you want to do that, but it would be nice to have a standardized analog I/O circuit to play with: microphones, light sensors, etc.
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ld a, 0 ld a, a
Keoni29
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Reply #7 on: 09 June, 2012, 09:34:29 »
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How about multiplexing it with an ADC as well? I'm not really sure if you want to do that, but it would be nice to have a standardized analog I/O circuit to play with: microphones, light sensors, etc.
That's possible, but more complex than a separate DAC and ADC. I don't think the TI84+ is capable of recording sound and playing it back. The playback is possible, but the recording and processing is pretty much impossible without proper I/O. You could also just hook your calc up to an arduino since it features pwm and ADC.
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Keoni29
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Reply #8 on: 25 June, 2012, 11:21:34 »
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Now building the DAC
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Keoni29
I'm going to solder this up this weekend. I made it on a solderless breadboard first and it works just fine. If there are other people interested in this device: just let me know. I'll release the source code for the subroutines which drive this thing.
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Keoni29
I just soldered it up and I got it up and running. Also, I made an instructable which can be found down below.
« Last Edit: 10 July, 2012, 21:22:03 by Keoni29 »
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Keoni29
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