I want to make an electronic lock, I mean a lock that I can control from my desktop..... What I really want to do is to connect an infrared transmitter circuit to my computer and then have a receiver circuit collect the information sent by the transmitter. But i realize that I need a knowledge of control of my PARALLEL PORTS, but I have no idea on how to control this ports.... I would be grateful if anyone with any idea of how to go about this can shed some light for me......
Read overhere: "Your text to link here...(Description)":http://logix4u.net/component/content/article/14-parallel-port/15-a-tutorial-on-parallel-port-interfacing
Ill give you some good advice before you start this one Some years ago Microsoft changed the way that you address parrellel ports This really depends on what operating System you are using, but if you are using xp you need or should I say sopposidly need an extra driver so that you can talk to the parrellel port
Despite downloading this and installing various recomended solutions Ive never got one of them to actually work In fact ive had so many problems with this I gave up with this
So did lots of other people Good engineers as well not second rate engineers by any means of imaginatiion I now use the serial port or a virtual serial port with external hardware and then convert serial data to parrellel data and visa versa
Advantages of doing this You dont have to buy third party software for parrellel port
The serial port always works You can handel interrupts from external hardware plugged into serial port So that means you could also attach Irda for example :
You can still operate your locks from the same hardware Parrallel port is slowly being phased out
Ask here how many printers do you see with parrallel port Answer hardly any at all
The only os that will possibly still work with parrellel port is possibly unix linux or possix or windows 98 or dos
This is typical microsoft for you We dont honestly believe it had anything to do with os Most of us believe they did this deliberatley because odley enough this occurred and changes occurred during the Iraq war So we think they must have got scared and realised what people might do with internet related technology with regards setting up a terrorist ring In other words one button press One tcp/ip message one massive explosion
So I would first develop usb or serial external hardware Interface to pc via front end and approach this way
But i definitatley know fact that all purchased software inclusive the so called parrellel port drivers etc have never worked with Xp and i have both and both are bonified liscenced software
Im none to pleased with them either As I could have had numerous projects working years ago if it wasnt for this
What I will do is attach a zip file for you which includes an exe plus installer plus dll file which supposidly enables port access There are also other files with info inside You will need to visit www.7-zip.org. and download the correct exe to extract the zip file but as I said I never got this to work except through good old fashioned dos, c, Qbasic, and windows 98, 95
But you can try it and see who knows you may even be able to dissassemble the file and found out why if so Id be very inyetested in your answers and how you might be able to correct this
Shame I cant write driver files Id be worth a bomb by now
hn fact here is another upload you might like try as well Again i could never get this to work either but once again you are welcome to try this too
In fact of I cant think of any one that would go to these extremes to stop you from being productive and creating something interesting and worthwhile but there you go such is our great leadership Everyone as usual has to suffer becuase of thier lust for power Not difficult to see why people cant stand each other is there anymore
Nevermind As they say this has a horrible way of backfiring personally I hope they sue them and make an example out if few of them if not worse
You can also refer to this site Very good site Id like too see someone put up a full tutorial and how to write your own driver files with links to what you have learn to get to that point
You might also like to try this This was the java interpretation of the port driver so you could use java to write and read from parrellel ports but they gave up with this as well, same reasons also had problems with xp drivers for the port
To use this your need to be able to write native methods Again id like to see more people turn hands to this as well A great crying shame that Sun / oracle wont apply reasoning here making this extremley interesting for not only bussiness but also science and engineering
Any way its there if you fancy giving this a whirl
I don't respond to private messages, so I will share what you sent me, here, so the forum can respond:
bq). Concerning my question on using parallel ports, I think I would like to follow your suggestion of USB. I read your profile, and couldn't help but notice that you do Java programming, well, I do a little of Java too, and concerning my project, I would like to make it in such a way that I would create a simple GUI with two buttons or a toggle button that does the locking and unlocking for me...... Thanks
It's been a long while since I worked my Java chops Looks like Mark may be more up-to-speed on Java than I. My focus, lately, has been HTML5/PHP and C for PIC microcontrollers.
And, it's really not that hard. Just jump in and as you encounter problems, post here, or find forums specific to your task (such as USB to Serial or FTDI).
OK, time for me to get "old guy" -- back in my day, we had to figure it out for our selves or find a book or magazine article that gave us the help we needed -- we didn't have this new-fangled Internet thingy! Why, you youngsters have it SO easy!! I have dents in my head from all the pounding as I agonized over why my transistors kept going up in smoke or why the flaming OP-AMP summarily ignored anything I shove at it's input!
Tenacity, imagination, daring -- these are the ingredients for success. FAILURE!! Fail over and over! That's how you achieve success. Lots of smoke!!
But seriously, get your feet wet, you may find that the water ain't so bad, the sharks not so hungry. And when they _do_ start nipping at you, you have a grand safety net that we never had -- you can ask, you can search, you can get support like never before!
You can still use the serial port You can have this in java or you can have this in Csharp up to you or via usb
There is a java usb package available but ive not tried this yet Difficult without pc internet access
I only manage conversation on here with mobile phone Thats how I currently upload and comment All done from my hard working android samsung mobile phone
If you look carefully at projects page located on this site You will see a usb serial hardware project using ftdi chip plus pcb layouts plus how too, all written up for you plus a gui for testing the ftdi chip after youve finished making the project Also up on this site for you to download
Link below for you www.eeweb.com/project/mark_harrington
Also I need to know command words you are sending to your hardware in byte or ascii format But the gui no problem It would be nice if you can give me also some type of instructions or project pre requisits of what you want the gui to do also perhaps a drawing by hand or with paint shop pro An artistic drawing showing rough idea of layout buttons Any help files that you might want, password fields Gui components such as may be led indicator 7 segment display, scrolling markees, lets what else might you want really just to let me know or give me some ideas of what you want as a visual interface port settings maybe
If you really fancy making this interesting You could also implement smart card readers or media framework which will give you Webcam viewing of area and you could implement ftp upload or live stream Or you coukd turn this into server application through which you might access via mobile phone or from internal gsm modem in a vehicle using touch screen tft Lots of ideas to make this interesting and marketeable or you could opt for rasberry pi as hardware
Im yet to play with this and youve got comp video out
Im sure they can add rgb output Youve got a memory card on this ethernet port, usb port, hdmi out, port io
Anyway lots of things you can do with this nevermind intergrate wireless, bluetooth live stream music content Blimey
Got to be interesting
Its your call isnt it Depends only on you or you can break down old pcs use motherbourds still good enough to do lots of things
Lets try again James 1 Build a circuit using a simple pic micro with either ftdi chip or use a max232c rs232 level converter
Where from can you buy this www.farnel.co.uk Rs components look it up Where else Maplins my favourite enemies Uhm correction no you cant not from maplins they dont keep them in stock, Not to worry
Where else
Ebay
Where else
FTDI.COM EVEN COMES WITH DATASHEET PLUS DRIVERS THE LOT
FTDI PROJECT ON WEB SITE FOR YOU SO THATS CONVERTOR FOR USB DONE FOR YOU
see link in comments above
What else do you need look at the old bourds they throw away
What have you got D type connectors, relays, transisitors really stuck ask we might even have a few you for a tiny price plus postage
You could even make a few of these are go and sell them yourself or ask a pcb mnfr to make them for you Theres the money for your bits and pieces, programmer what ever
Goto my site www.harrington.force9.co.uk
Halfway down the page low and behold is a pcb mnfr for you who will even make them for you Click on the advert
2 Program the chip to recieve an Rs232 signal from the Pc 3 Write a front end in the langauge of your own choice we have suggested either Java becuase its cross platform, fairly easy to use, and can use javax.comm package, also fairly simple for peer to peer networking as well
Free for download as well No licence required jdk7 is the latest binary
Or use dot net csharp why, same reasons explained
Multi threading not too difficult either, little tricky but can be done
If using linux guess, Yes youve even got mono ide for developing, comma, pause, deep huge breath, ready to commit comakazi
Congrats James.... You can now develop C sharp apps on Linux boxes too
Linux is also free for download as well There is suzi linux, ubantu, Red hat Up to you solves another problem lots of free art packages included etc etc
And what else. .......
Yes James Microchip have given you Mplabs x for linux or windows
And what else James......... Congrats "pulling my hair out " ,
Oracle have a free ide, so do netbeans, so do Codeblocks and so, does Eclipse
A little bit of effort and self tuition in otherwords read some documentation
What can you do with these use them for ava or c or php or ruby or c for micro including atmel or even android for mobile phones or even html or php mysql xml and java beans. And of course c plus plus
Why have we said this because of years of experiance we know there is a problem with parrallel port drivers even explained why
5 If you tell us what you want do some very simple drawings doesent have to be involved we will even help you with this as well
Now whats the problem James. ? ?
There you go no doubt we will have a row over this as well
For the GUI (i.e. the software buttons) there's also:
* Visual Basic (VB) [Very easy, quite powerful, great GUI building tool for beginners but expensive -- check eBay for older version {don't necessarily need the latest}, also consider "Standard Edition" {but check to see if it supports serial port access or has USB tools}] * Delphi [Object Pascal with powerful GUI building tools] * Tcl/Tk (FREE and easy!) [Tcl {pronounced "tickle"} is a powerful, mature (been around for decades), cross platform, easy to use scripting language and Tk is a GUI "toolkit" for Tcl] * http://wiki.tcl.tk/447 [serial port on Tcl -- but may have problems -- the idea is to use the built-in virtual serial port {com: port} driver to access the USB port {someone correct me if I'm wrong, it's been awhile since I did this sort of thing}] * http://wiki.tcl.tk/1838 [another Tcl serial port reference] * http://wiki.tcl.tk/4307 [Tcl and USB]
I said that Tcl/Tk was "Free". It used to be, but I took a cursory look and it appears that the uncompiled version may be free, but you may have to pay for a "distribution" (basically, they compile it for you and charge you for the service -- support might be part of the cost, as well), but I don't have time, right now, to dig any deeper, but it's probably worth looking into
To get true direct access under the WindowsNT-like OS (also for the DOS task under the Windows) to the ports (Include LPT ports) You can use this toolkit.
But, be sure to backup the Registry before doing things like that (i.e. making changes in the registry). If things go awry, boot up in Safe Mode and restore the registry from the backup.
✨ The discussion addresses controlling PC parallel ports for an infrared electronic lock project. Key challenges include limited direct access to parallel ports on modern Windows OS (especially XP and later), requiring special drivers or registry modifications such as disabling LPT polling via the registry key "DisableWarmPoll". Many users report difficulties with parallel port interfacing due to OS restrictions and driver issues, leading to recommendations to use serial ports or USB interfaces instead. USB-to-serial or USB-to-TTL converters (e.g., FTDI chips, PL2303HX modules) are suggested as more reliable alternatives. Several tutorials and toolkits are referenced for parallel port interfacing, including resources at logix4u.net, beyondlogic.org, and eeweb.com. Programming options for GUI control include Visual Basic, Delphi, Tcl/Tk, Java (with native method calls), and C#. Some users recommend microcontroller-based solutions using PIC MCUs with RS232 level converters (MAX232C) or FTDI chips for USB communication. Registry editing advice includes backing up before changes and awareness of 32-bit vs 64-bit Windows differences. Additional ideas include integrating smart card readers, webcams, or Raspberry Pi for advanced control and networking. Overall, the consensus favors using serial or USB interfaces over direct parallel port control due to modern OS limitations and driver support challenges.
TL;DR: For desktop-controlled IR locks, skip legacy LPT and use USB‑to‑serial; Steve shared 5 example adapters and noted, “what you want is a USB to TTL.” [Elektroda, Steve Lawson, post #21665948]
Why it matters: This approach works on modern PCs, simplifies coding, and avoids brittle parallel‑port drivers—perfect for beginners building reliable locks.
How do I control a PC port for an infrared lock in 2025?
Use a USB‑to‑serial (USB‑to‑TTL/RS‑232) adapter and drive a microcontroller (e.g., PIC/AVR) that switches your IR transmitter/relay. This avoids fragile LPT access on modern OSes and gives you a stable virtual COM port for your app. Steve’s post lists multiple adapter options. [Elektroda, Steve Lawson, post #21665948]
Should I avoid the parallel (LPT) port for new builds?
Yes. LPT is phased out on new PCs and driver access is inconsistent on NT/XP and later. Engineers in the thread moved to serial or USB front ends because they "always work" across systems. That reliability matters for locks and safety. [Elektroda, Mark Harrington, post #21665942]
What exactly is a USB‑to‑TTL/USB‑to‑RS232 adapter?
It converts USB from your PC into a UART signal (TTL level or RS‑232 level) that microcontrollers understand. Common chipsets include FTDI; vendors like SparkFun, Adafruit, and Parallax sell ready modules. Your PC sees a COM port you can open from most languages. [Elektroda, Steve Lawson, post #21665948]
Quick 3‑step: how do I build a simple USB/serial front end for the lock?
Hardware: Pair an FTDI module or a MAX232 RS‑232 level shifter with a small MCU to drive your relay/IR LED.
Firmware: Parse simple bytes/ASCII over UART to toggle lock states.
How can I access the LPT port on Windows XP/NT if I insist on using it?
Use a port‑access toolkit/driver designed for NT‑like systems to gain user‑mode I/O to LPT registers. This enables experiments or legacy hardware under controlled conditions, though it’s more brittle than USB‑serial. [Elektroda, Eugene Lisovy, post #21665961]
Is editing the Windows registry safe for LPT tweaks?
Treat it as risky. Back up the registry first. If something breaks, boot Safe Mode and restore. A single typo can derail your system. As Steve cautioned, "better safe than sorry." [Elektroda, Steve Lawson, post #21665965]
How do I disable Windows XP’s LPT polling and why would I?
DisableWarmPoll=1 under the Parport\Parameters key stops periodic LPT polling that can interfere with direct port experiments. This is an advanced change; document and back up before editing. [Elektroda, Eugene Lisovy, post #21665964]
Can a beginner build the GUI to lock/unlock?
Yes. Options include Visual Basic, Delphi, or Tcl/Tk. Each can open the adapter’s COM port and bind buttons to send bytes. Tcl/Tk is cross‑platform and approachable; VB offers a very friendly designer for quick results. [Elektroda, Steve Lawson, post #21665958]
What languages and tools did the thread suggest for the PC side?
Java, C#, VB, Delphi, and Tcl/Tk were suggested. Mark noted JDK7 was then current and highlighted cross‑platform benefits. Choose what you know; serial libraries exist for all. [Elektroda, Mark Harrington, post #21665956]
What’s FTDI, MAX232, LPT, and TTL in simple terms?
FTDI: USB‑UART bridge chips/modules. MAX232: converts TTL UART to RS‑232 levels. LPT: legacy 25‑pin parallel printer port. TTL: 5V/3.3V logic UART signal for MCUs. These terms appear across the suggested hardware paths. [Elektroda, Steve Lawson, post #21665948]
Is there a low‑cost DIY bridge if I must keep LPT hardware?
Yes. An AVR‑based USB2LPT project emulates a printer port over USB, useful for legacy devices when native LPT is unavailable. It includes schematics and firmware. [Elektroda, Eugene Lisovy, post #21665966]
Any beginner‑friendly learning resources or communities?
SparkFun tutorials and support forums are solid starting points. Follow a guided USB‑to‑serial example, then adapt it to send your lock commands. Ask questions as you hit roadblocks. [Elektroda, Steve Lawson, post #21665952]
Can I configure or test ports with HyperTerminal?
You can test serial communications with HyperTerminal by opening the virtual COM port and sending bytes to your MCU. It does not configure LPT, but it’s handy for serial debugging. [Elektroda, Aniruddh Mali, post #21665957]
What pitfalls should I expect on Windows XP and drivers?
Expect driver hurdles, 32‑bit vs 64‑bit confusion, and tools that work only in DOS/Win9x. Many gave up on LPT under XP and pivoted to serial/USB. Plan for that fallback early. [Elektroda, Mark Harrington, post #21665972]
Where can I read a primer on parallel ports?
Start with the tutorial linked in the thread. It explains LPT basics, signals, and interfacing concepts useful for understanding legacy control paths. [Elektroda, Eugene Lisovy, post #21665939]
Is Tcl/Tk still free for hobby use?
Yes. ActiveTcl offers a free Community edition with forum support, suitable for learning and small tools that talk to COM ports. [Elektroda, Steve Lawson, post #21665960]
Looks like Mark may be more up-to-speed on Java than I. My focus, lately, has been HTML5/PHP and C for PIC microcontrollers.
