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| [Solved] was: Need electrical circuit help (Rotating Monitor w. Parallel Port) |
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| richms:
you program it in a pre made development environment - there is a loader on the chip so its as simple to program as clicking a button on the development environment. So you could program it so it waits in a loop for a character from the computer over the USB, then it will turn on the motor, wait a time limit then turn it off, or go untill it reads a switch has triggered, then send something back to the computer and turn the monitor on. Its really up to you, but since its all running in the microcontroller on the arduino theres not much the PC can do to stuff up the operation of it, whereas doing the motors directly means that if the PC crashes or whatever it could leave something on and burn the motor out etc. The arduino boards have a USB serial port converter on them, so they just show up as COM6 or whatever to the computer. |
| MonMotha:
An Arduino is an Atmel AVR on a board with certain characteristics (including a FT232 or similar USB<->UART adapter), a custom bootloader to allow it to be programmed via the serial port (USB) interface, and a development environment that's basically C++ with a TON of macros that attempt to make things easier for novices. It's kinda like programming a Lego Mindstorms kit in NQC, if you've ever done that. If you're not at all comfortable with programming, it would still be a bit of a step to use something like an Arduino (or any microcontroller that you're tasked with programming). The Arduino libraries/macros make it a little easier than programming the "bare metal" directly, but you still have to be familiar with basic loops and such. You just don't have to bang on registers directly (very often). For "safety critical" (or just applications where hardware destruction could result if things go wrong) or real-time applications, an external micro can be a welcome addition since it brings its own isolated running environment to the table. If you just want to blink a light, it's probably overkill. A lot of things people use these little MCU boards for seem to simply be because PCs lack good GPIO. A parallel port is pretty close, but many PCs don't have them, and modern OSes can place some impossible or difficult to remove assumptions on the port that aren't compatible with using them as GPIO (like you've noticed). I guess just do whatever works. I don't know exactly what you're doing, but I'd probably use the parallel port. However, I run Linux, which can be made to not attempt IEEE1284 negotiation pretty easily. I seem to recall that's difficult or impossible on Windows. |
| Level42:
Good info, I can see the advantages now. Also nice because it will work on Mac's that don't have parallel printer ports. Interesting stuff, thanks. |
| csa3d:
--- Quote from: csa3d on January 25, 2009, 12:31:40 pm ---Back to my circuit, putting the monitor unit back in the cab broke something, or is shorting.. because it's not working properly once again.. :censored: --- End quote --- Ok, figured out why things were shorting. When I mounted the PCB I used left over U-Brackets from my U360 joystick after installing restrictor plates. They can be seen here in black elevating the yellow PCB: Guess what, they are made of metal just like the copper and exposed wires on the back of the PCB. They happened to be shorting out the new logic to the Pin 9 logic gate. I took my utility knife and cut one of those plastic wire screw-downs (also illustrated above ) to create two plastic washers which I sandwhiched between the PCB and the metal brackets. No more short, and a properly rotating monitor! Hoo-RAY! @DaOldMan: Thanks for all your help on this circuit! I'll transfer this info over to my project thread in a bit now that I got it all worked out. Also, the pportreader.exe is working splended! @Others: That card seems like a pretty nice way to implement a "plug-n-play" solution to this rotating business. Though, the printer port circuit above WITH the red highlighted section wired in instead of directly grounding the commons seems pretty fail safe as well if you take the time to check your printer pin bootup patterns ahead of time. Thanks to everyone who helped me through this issue! -csa |
| DaOld Man:
Glad to help out. If you repost that drawing above, in the note at bottom I said to wire pins 18,19,20,21,22,23,24, 15 together. Thats not correct. It should read 18,19,20,21,22,23,24,25 (all the grounds.) I dont want to scew someone up.. |
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