LCD Display - Electronic Circuits Projects Diagrams Free

karenhornby · 20th February 2008, 06:20 PM

I need help please.
Has anyone got any circuits for an LCD display that DOESN'T need a pic or similar to program it?
What i want ideally is a 1 line LCD display that will display one of 3 WORDS, that are preset.
It only has to display 3 words, one being DIESEL, the others being VEG OIL and PURGE, 1 at a time which one depending on which is selected by a switch or similar

IF it helps, I've attached a circuit diagram of what it will be connected to, basically when solenoid 1 and 2 are on together, it would read "VEG OIL", when both solenoids are off it would read DIESEL, and when S1 is pressed ( only solenoid 2 is active) it would read "PURGE"
ANY ideas welcome, or any other suggestions

Super_voip · 20th February 2008, 06:57 PM

I suppose it could be done with an EPROM or diode matrix but the programmer for an EPROM will cost far more than any combo of PIC or 8051 including the programmer. A diode matrix will take up a lot of space but could be done.

blueroomelectronics · 20th February 2008, 07:01 PM

Why not just use indicator lights?

karenhornby · 20th February 2008, 07:03 PM

The reason I didn't want to use a pic is I've no idea how to program them, and probably dont have whats needed anyway.

What I'm thinking at the moment is the Velleman K8045 kit, if I can get hold of one

Anyone know anything about this one?

karenhornby · 20th February 2008, 07:04 PM

Quote:

Originally Posted by blueroomelectronics

Why not just use indicator lights?

Already have indicator lights on the circuit, but I was hoping to make it easier to see and less confusing if anyone else was driving the car hence the LCD idea

blueroomelectronics · 20th February 2008, 07:43 PM

Low tech indicator lights are still used as they are generally much easier to read than an LCD display. Color also helps convey information.
The Velleman K8045 would appear to suit your application.

Super_voip · 20th February 2008, 07:44 PM

The velleman kit looks rather large, and it has a high difficulty rating. You already have the most expensive part of a PIC programmer, the PC. PIC programmers can be built very cheaply, the code can be done in Basic and the circuits take little space.

blueroomelectronics · 20th February 2008, 08:22 PM

Well I could mod an old prototype kit I made called Robin. I've got about 100 PCBs left. It's designed for a 2x16 LCD though but a 1x16 should fit, with backlight control. Four inputs could be programmed easy enough.

kchriste · 21st February 2008, 03:58 AM

You could use a laptop to control it. But this would be overkill:
http://www.electronics-lab.com/proje...020/index.html
Now, if you used LED displays, you could easily do this with a simple diode matrix. The V wouldn't look that good on a seven segment display but you could use 14 segment alpha types:
http://www.globalspec.com/FeaturedPr...isplay/49901/0
The most elegant solution is a microcontroller like a PIC connected to your LCD. Then you could dump the 555 timer and most of the other circuitry also....
As mentioned, you could use large indicator lights with the words DIESEL etc engraved on the bezel.

Torben · 21st February 2008, 09:24 AM

Quote:

Originally Posted by karenhornby

Already have indicator lights on the circuit, but I was hoping to make it easier to see and less confusing if anyone else was driving the car hence the LCD idea

Hi Karen,

I can't off the top of my head think of a simple LCD display which would be easier to read while driving than bright indicator lamps.

What lamps are you using at the moment? If they're well-driven auto indicators they should be plenty bright. If you want to make them easier to tell apart, I'd try labeling them (maybe put one behind an opaque material with a cutout of the word 'Diesel' or 'D' and the second behind a cutout of 'Veg oil' or 'V', and the last behind 'Purge' or 'P') and make the lamps different colours. Or just use one of those tape labelers. The big thing is that drivers will quickly associate the colours of the lamps with the status so a quick glance will do the trick.

Just a thought.

Good luck with the project whatever you wind up doing--it sounds really cool.

Torben

Shax · 21st February 2008, 02:32 PM

To do what you need with a PIC will only take 30 or so lines of Proton Picbasic..
I just lashed up some quick and dirty (aka untested!!) code to show how simple it really is!!!

House0Fwax · 21st February 2008, 05:45 PM

Quote:

Originally Posted by karenhornby

Velleman K8045 kit, Anyone know anything about this one?

I have one. It was very easy to build and works very well.
If you are in the U.K. Maplin sell them ready made ( more expensive than the kit though )
However, you need to have a serial port, from things I've read on the net they don't work with USB adaptors.

Then have a look at Nigel's LCD routines ( Tutorial 3 ), adapt the code to suit your needs.
Job done.

karenhornby · 21st February 2008, 06:59 PM

Thanks everyone for the suggestions, maybe I should try and figure out this pic stuff.
What exactly would I need to make it work, ie program the pic and how many external components are needed with it and how would you interface it to a display etc?
Sorry for so many questions but I'm intruiged now, the idea of losing components like the 555 timer circuit and possibly even more seems good to me unless its pretty expensive to but the bits needed to program a pic and learn as i dont want to spend like £100 just on something I could buy already made for less than a 3rd of that ready done such as the velleman kits

Anyone know of a single or two line LCD display module? with blue backlight? or that you can change the backlight to a blue one?

By the way... Nigel's LCD routines? (turorial 3) where would i go looking for that?
And any ideas of a simple dummies guide to writing pic programs as the bit SHAX sent has got me interested, I was thinking it would take maybe thousands of lines of code to write something, but at the moment I know NOTHING whatsoever about programming pic chips.
Last thing... i do have an rs232 port on my computer, I wont have one without that even though its getting old, some things rely on rs232 still

SPDCHK · 21st February 2008, 07:10 PM

Quote:

Originally Posted by karenhornby

Thanks everyone for the suggestions, maybe I should try and figure out this pic stuff.
What exactly would I need to make it work, ie program the pic and how many external components are needed with it and how would you interface it to a display etc?
Sorry for so many questions but I'm intruiged now, the idea of losing components like the 555 timer circuit and possibly even more seems good to me unless its pretty expensive to but the bits needed to program a pic and learn as i dont want to spend like £100 just on something I could buy already made for less than a 3rd of that ready done such as the velleman kits

Anyone know of a single or two line LCD display module? with blue backlight? or that you can change the backlight to a blue one?

By the way... Nigel's LCD routines? (turorial 3) where would i go looking for that? http://www.winpicprog.co.uk/pic_tutorial3.htm
And any ideas of a simple dummies guide to writing pic programs as the bit SHAX sent has got me interested, I was thinking it would take maybe thousands of lines of code to write something, but at the moment I know NOTHING whatsoever about programming pic chips.
Last thing... i do have an rs232 port on my computer, I wont have one without that even though its getting old, some things rely on rs232 still

The full tutorial can be found here http://www.winpicprog.co.uk/

karenhornby · 22nd February 2008, 12:05 AM

Its pretty heavy reading this time of night but it looks interesting, and IF I've got the basic idea right......

Is it possible to program a PIC to measure two temperatures via some sort of probe? and once a preset temp has been reached (possibly by setting an LM35dz circuit?) activate a circuit (or two) that would then operate relays? and display on the LCD display one of a number of messages depending on which output was active, while say the 2nd line of the display would display a 3rd temperature (to be measured also)

sorry for so many questions "again" but i'm finding this quite interesting and yearn for knowledge

but not having a programmer yet, or a development kit im resigned to learning by reading for the moment

20th February 2008, 07:01 PM	(permalink)
blueroomelectronics Experienced Member Blog Entries: 4	Why not just use indicator lights? __________________ Bill Smart Kits build Smart People http://www.blueroomelectronics.com

20th February 2008, 07:03 PM	(permalink)
karenhornby Experienced Member	Velleman K8045 kit? The reason I didn't want to use a pic is I've no idea how to program them, and probably dont have whats needed anyway. What I'm thinking at the moment is the Velleman K8045 kit, if I can get hold of one Anyone know anything about this one?

20th February 2008, 07:43 PM	(permalink)
blueroomelectronics Experienced Member Blog Entries: 4	Low tech indicator lights are still used as they are generally much easier to read than an LCD display. Color also helps convey information. The Velleman K8045 would appear to suit your application. __________________ Bill Smart Kits build Smart People http://www.blueroomelectronics.com

20th February 2008, 08:22 PM	(permalink)
blueroomelectronics Experienced Member Blog Entries: 4	Well I could mod an old prototype kit I made called Robin. I've got about 100 PCBs left. It's designed for a 2x16 LCD though but a 1x16 should fit, with backlight control. Four inputs could be programmed easy enough. __________________ Bill Smart Kits build Smart People http://www.blueroomelectronics.com

21st February 2008, 03:58 AM	(permalink)
kchriste Experienced Member	You could use a laptop to control it. But this would be overkill: http://www.electronics-lab.com/proje...020/index.html Now, if you used LED displays, you could easily do this with a simple diode matrix. The V wouldn't look that good on a seven segment display but you could use 14 segment alpha types: http://www.globalspec.com/FeaturedPr...isplay/49901/0 The most elegant solution is a microcontroller like a PIC connected to your LCD. Then you could dump the 555 timer and most of the other circuitry also.... As mentioned, you could use large indicator lights with the words DIESEL etc engraved on the bezel. __________________ --- The days of the digital watch are numbered. --- Last edited by kchriste; 21st February 2008 at 04:02 AM.

20th February 2008, 06:57 PM	(permalink)
Super_voip Experienced Member	I suppose it could be done with an EPROM or diode matrix but the programmer for an EPROM will cost far more than any combo of PIC or 8051 including the programmer. A diode matrix will take up a lot of space but could be done.

20th February 2008, 07:44 PM	(permalink)
Super_voip Experienced Member	The velleman kit looks rather large, and it has a high difficulty rating. You already have the most expensive part of a PIC programmer, the PC. PIC programmers can be built very cheaply, the code can be done in Basic and the circuits take little space.

21st February 2008, 06:59 PM	(permalink)
karenhornby Experienced Member	Thanks everyone for the suggestions, maybe I should try and figure out this pic stuff. What exactly would I need to make it work, ie program the pic and how many external components are needed with it and how would you interface it to a display etc? Sorry for so many questions but I'm intruiged now, the idea of losing components like the 555 timer circuit and possibly even more seems good to me unless its pretty expensive to but the bits needed to program a pic and learn as i dont want to spend like £100 just on something I could buy already made for less than a 3rd of that ready done such as the velleman kits Anyone know of a single or two line LCD display module? with blue backlight? or that you can change the backlight to a blue one? By the way... Nigel's LCD routines? (turorial 3) where would i go looking for that? And any ideas of a simple dummies guide to writing pic programs as the bit SHAX sent has got me interested, I was thinking it would take maybe thousands of lines of code to write something, but at the moment I know NOTHING whatsoever about programming pic chips. Last thing... i do have an rs232 port on my computer, I wont have one without that even though its getting old, some things rely on rs232 still

22nd February 2008, 12:05 AM	(permalink)
karenhornby Experienced Member	Brain burnout Its pretty heavy reading this time of night but it looks interesting, and IF I've got the basic idea right...... Is it possible to program a PIC to measure two temperatures via some sort of probe? and once a preset temp has been reached (possibly by setting an LM35dz circuit?) activate a circuit (or two) that would then operate relays? and display on the LCD display one of a number of messages depending on which output was active, while say the 2nd line of the display would display a 3rd temperature (to be measured also) sorry for so many questions "again" but i'm finding this quite interesting and yearn for knowledge but not having a programmer yet, or a development kit im resigned to learning by reading for the moment

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