Hi all,
I know it must be really frustrating for you guys to have to answer the basest of questions but I'd really appreciate some help. I have all the software and plug ins and things i'd need to start hooking up some slick lcds, the only question I have is: What components do I need to hook up an lcd to my laptop's parallel port? I've decided on a very basic (yet compatible) lcd screen from Matrix Orbital (Which is the compatible HD44780 standard)
http://www.matrixorbital.com/product_in ... acter-lcds
Do you know where i would be able to purchase a pre-assembled parallel cable with a power cable as well? I know I won't be able to make the cable myself.
Our new official repo is on github
LCD Smartie version 5.6 is released!
Download it now: https://github.com/LCD-Smartie/LCDSmartie/releases
LCD Smartie version 5.6 is released!
Download it now: https://github.com/LCD-Smartie/LCDSmartie/releases
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ReverseEngineered
- Plugin Author
- Posts: 192
- Joined: January 18th, 2006, 11:09 pm
- Location: Saskatoon, Saskatchewan, Canada
Molex power cables are the larger power connectors inside a computer, normally connected to CDROMs and hard drives. They have four wires, 2 black in the middle with a yellow and red on the outside. The ones found in computer power supplies are female connectors; you will need to connect a male connector to your LCD if you want to use the power from the computer.
The basic components necessary to interface an LCD are a male DB25 connector (solder pot type), a variable resistor, and a power supply. I would say to check Radio Shack, but they are usually quite expensive. If there is a local electronics shop, ask them. You'll also need some wire, and soldering materials (solder, soldering iron, flux, etc). Your power supply could be any old power supply that you plug into the wall from some old toy. Look at the ratings on the front of the supply (most of them have these listed). You want one that says 5VDC and at least 200mA.
I buy my power supplies at a local surplus store, Princess Auto. Presumably there are more of these around Canada and the US, but I'm not sure if there will be one in your area. The DB25 connector and variable resistor would have to be bought from an electronics supply store, or online. Check Digikey.com. Their prices are...okay, and they ship to many countries.
Overall, you definitely need the variable resistor and DB25 connector, but you have an option with the power supply: either buy a male molex connector (you can get the cheap by buying splitters at a computer store) and hook it directly up to the computer, or find a cheap 5V power supply and cut the end off. Note that hooking up the power backwards will (probably) fry your LCD instantly, so be careful. I've already killed one because of this!
With a little patience and the right documents (LCDSmartie's webpage lists which pins on the DB25 go to which pins on the LCD), it's very easy to make the cable. Just make sure the wires aren't longer than 30cm or you might run into problems. I would recommend making the wires to the DB25 very short and buying a parallel port extension cable. These cables are built much better and can be a few feet long without problems.
I suppose I could make cables, but after the cost of the parts, assembly, and shipping, you might not like the price.
It will be half the cost for you to buy the parts locally and make it yourself.
Best of luck!
The basic components necessary to interface an LCD are a male DB25 connector (solder pot type), a variable resistor, and a power supply. I would say to check Radio Shack, but they are usually quite expensive. If there is a local electronics shop, ask them. You'll also need some wire, and soldering materials (solder, soldering iron, flux, etc). Your power supply could be any old power supply that you plug into the wall from some old toy. Look at the ratings on the front of the supply (most of them have these listed). You want one that says 5VDC and at least 200mA.
I buy my power supplies at a local surplus store, Princess Auto. Presumably there are more of these around Canada and the US, but I'm not sure if there will be one in your area. The DB25 connector and variable resistor would have to be bought from an electronics supply store, or online. Check Digikey.com. Their prices are...okay, and they ship to many countries.
Overall, you definitely need the variable resistor and DB25 connector, but you have an option with the power supply: either buy a male molex connector (you can get the cheap by buying splitters at a computer store) and hook it directly up to the computer, or find a cheap 5V power supply and cut the end off. Note that hooking up the power backwards will (probably) fry your LCD instantly, so be careful. I've already killed one because of this!
With a little patience and the right documents (LCDSmartie's webpage lists which pins on the DB25 go to which pins on the LCD), it's very easy to make the cable. Just make sure the wires aren't longer than 30cm or you might run into problems. I would recommend making the wires to the DB25 very short and buying a parallel port extension cable. These cables are built much better and can be a few feet long without problems.
I suppose I could make cables, but after the cost of the parts, assembly, and shipping, you might not like the price.
It will be half the cost for you to buy the parts locally and make it yourself.Best of luck!
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Ngare
- Posts: 11
- Joined: February 23rd, 2006, 11:27 pm
I decided I'd settle for a cheaper e-bay LCD as apposed to screwing up a decent one so I bought this set up: http://cgi.ebay.ca/ws/eBayISAPI.dll?Vie ... %3AIT&rd=1
Also I found a guide that'll show me how to do the soldering but it doesn't mention anything about the need of a resistor... http://www.moddershq.net/guides.asp?guideid=13 Unfortunately I'm installing this set up on my laptop so I don't have access to the convenient pc power supply, would it be advisable for me to connect the ground and +5V input from a usb port with a hacked up usb cable?
Thanks.
Also I found a guide that'll show me how to do the soldering but it doesn't mention anything about the need of a resistor... http://www.moddershq.net/guides.asp?guideid=13 Unfortunately I'm installing this set up on my laptop so I don't have access to the convenient pc power supply, would it be advisable for me to connect the ground and +5V input from a usb port with a hacked up usb cable?
Thanks.
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ReverseEngineered
- Plugin Author
- Posts: 192
- Joined: January 18th, 2006, 11:09 pm
- Location: Saskatoon, Saskatchewan, Canada
The variable resistor is for setting the contrast. This is where the third pin (Vee) is used. Many guides (like yours) suggest connecting this directly to ground, which gives you the maximum contrast. While this usually works, I find my module's background is a little too dark at this level; it's much clearer if I turn it down just a bit. If you want to use the resistor, you'll notice it has three terminals. Connect one end to your +5V supply, the other end to ground, and the middle one goes to the third pin (Vee).
I do not recommend using the USB connector for +5V. The USB controller gets information from all of its peripherals to find out how much power they require; if it notices that there are too many things, it will shutdown some so that the others work. Also, USB is rated for 500mA max. Though your module shouldn't use this, with the backlight on it will use a good portion of this. This could cause any USB devices to malfunction, and could even damage the USB permanently!
If you leave the backlight disconnected you could do this, but I wouldn't really recommend it. Mind you...there aren't really a lot of other good options for a laptop, other than an external power supply. That's what I would go with. But, as long as you keep the backlight off, the 5V off of the USB would work. Just don't expect to use any other USB devices at the same time.
I do not recommend using the USB connector for +5V. The USB controller gets information from all of its peripherals to find out how much power they require; if it notices that there are too many things, it will shutdown some so that the others work. Also, USB is rated for 500mA max. Though your module shouldn't use this, with the backlight on it will use a good portion of this. This could cause any USB devices to malfunction, and could even damage the USB permanently!
If you leave the backlight disconnected you could do this, but I wouldn't really recommend it. Mind you...there aren't really a lot of other good options for a laptop, other than an external power supply. That's what I would go with. But, as long as you keep the backlight off, the 5V off of the USB would work. Just don't expect to use any other USB devices at the same time.
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ReverseEngineered
- Plugin Author
- Posts: 192
- Joined: January 18th, 2006, 11:09 pm
- Location: Saskatoon, Saskatchewan, Canada
I forgot to mention, LCDSmartie uses 8-bit communication (allows us to update the display twice as fast). The guide you have there only shows hooking up 4 of the data (DB) pins. You definitely need the other four, or nothing will work.
LCDSmartie's webpage actually has a simple circuit diagram available. Check out this page. You want the first circuit shown. That is the one I use (minus the backlight resistor, since mine doesn't require it) and it works great. You can use the same ribbon cable they show in your guide to do it, just make sure you hook it up as shown in the above diagram.
LCDSmartie's webpage actually has a simple circuit diagram available. Check out this page. You want the first circuit shown. That is the one I use (minus the backlight resistor, since mine doesn't require it) and it works great. You can use the same ribbon cable they show in your guide to do it, just make sure you hook it up as shown in the above diagram.
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jonny
- Posts: 48
- Joined: December 18th, 2005, 5:50 am
Ngare-- I use USB for my power supply, but i have it running to a USB hub, which has it's own power supply. I have had no problem with it, but I don't think I would plug it into my laptop for normal use. Not only for the reasons Rev. talked about, but also because it would take up one of my two USB ports. But it may be worth getting a cheap USB hub if you cant find a cheap 5v power supply.
Good luck with the wiring!
Good luck with the wiring!
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Ngare
- Posts: 11
- Joined: February 23rd, 2006, 11:27 pm
Sorry for taking so long to reply jonny, I just got back from a trip. I'm planning on connecting this and mounting it behind a wall so it's all slick looking. I'd rather have an external power adapter modified to fit the bill so I could wire it straight to a main outlet and shed the bulk of a USB hub . I dug through decades of crap in my basement and managed to dig up a few external power sources:
1. 12v 200mA
2. 9v 210 mA
3. 5V 2.4 A
Are any of these workable? I'm so incredibly sorry for being such a douche, I know my computer stuff pretty well but when it comes to circuits and the cool hands on stuff I'm not too good. Thanks again for all the help.
1. 12v 200mA
2. 9v 210 mA
3. 5V 2.4 A
Are any of these workable? I'm so incredibly sorry for being such a douche, I know my computer stuff pretty well but when it comes to circuits and the cool hands on stuff I'm not too good. Thanks again for all the help.