Are 4x20 LCD's compatible with AXE033/FRM010?

[GreenLeader]

I have an AXE033 with the standard 2x16 LCD display, all working fine.
For my project, I need a 4x20 or 4x16 LCD.
Can I use the AXE033 or the FRM010 with a 4x20 LCD?
If so, could anyone recommend a suitable 4x20LCD.

I've read the data sheets but they are not clear on whether 4x20LCDs are supported. The FRM010 data sheets shows a jumper to select 1 or 2 lines, which implies 4 lines are not supported?

Sparkfun have a 4x20LCD's for about $18 (http://www.sparkfun.com/commerce/product_info.php?products_id=256)


thanks

 

[kevrus]

Ive used the frm010 with 4x20 lcd displays without any problems.
The 4x20 display is actually a 2x40 but with the second half of the first line bieng used as line 3 and the second half of the second line bieng line 4 hence,
line 1 of a 4x20 starts at address '128'
line 2 of a 4x20 starts at address '192'
line 3 of a 4x20 starts at address '148'
line 4 of a 4x20 starts at address '212'

I hope that makes sense.

Check out e-bay as ive had some cheap but good displays from china with quick delivery to the UK.

 

[moxhamj]

kevrus - great tip re ebay. I had a quick search just now and found a lot more on www.ebay.com rather than uk or australia ebay and they don't charge much for shipping. Earlier today I got a little picaxe project going with a display measuring some things and it sure makes debugging a lot easier with a display. I'm starting to think of using displays a lot more at these prices.

Displays all seem to use a common format - even the 1 line ones I found in the back of a drawer worked fine (they were 2x8 characters in the software and 1x16 lines on the display). Makes one think about a generic routine that sends out an alphabet to a display to all the possible lines and then see what is displayed.

 

[Michael V]

Another display

Hi Green Leader,
Sounds like you are sorted out with FRM-010 - not that i know what that is.

To answer your original question, if you are looking for variety, you can get a range of different colour and backlight LCD modules from www.modtronix.com.au, they also have outlets in the UK and Germany.

You can get just the LCD, a LCD daughter board module, or just the daughter board. You commmunicate via I2c or SPI. I have had heaps of help on this forum with I2C, and it is easy now. - tip, you need to switch the tiny jumpers on the module as it comes as SPI default. The 2 X 16 and 4 x 20 are controlled the same way, and the 16x 20 supports a large character set which can be very cool, i haven't tried it yet. They also works using the I2C fast command rather than I2C slow, if that makes a difference to the display speed it could be advantageous to you project. You can also attach a keyboard to the LCD module itself, which might be useful if your processor and display are not in the same place, or you just want to limit connections, as i do.

Michael

 

[GreenLeader]

Thanks to all for comments above.
I have purchased on eBay two white/blue 4x20LCD's from China ("Sure Electronics" model DE-LM005), at very reasonable cost - $27 incl shipping for both.

They arrived within 2 weeks and I've hooked them up to my AXE033 in lieu of the original 2x16 and they work fine so far. The address for the 4 lines given by kevrus was spot on..

Only issue is that they are very faint without the backlight, but that might be the contrast potentiometer on the AXE033 not being suitable? My next step is to buy the FRM010 firmware and hook that up directly, then I can try changing the potentiometer to see if that resolves the problem..

 

[kevrus]

Greenleader, I think there are facilities available for the LCD backlight to be connected when using the AXE033. You should find two unused connections on the LCD module (15 & 16) which should correspond with two spare header connections on the board. Also a resistor will need to be fitted for which I think there is space.
I've used the same 4x20 displays from Sure Electronics and find that a 220 ohm resistor gives a good level of brightness without drawing too much current. The data sheet for the DE-LM005 gives a max. current for the backlight of 80mA so you could drop resistor value to 68 ohms.

 

[GreenLeader]

Hi Kevrus
Thanks for the tip - I have used a 330R resistor - powering backlight directly ie without using the AXE033 pins - seems to work OK.

How do you find your display contrast without the backlight?

Mine is not really usable without the backlight..

 

[kevrus]

There are basically three types of display,
reflective: which allows the display to be seen by ambient light cannot usually be backit

transmissive: allows the display to be seen by use of a backlight and difficult to see without the backlight

transflective: can be seen in bright ambient light or can use a backlight for use in low lighting conditions.

I think that the type you have is the transmissive hence the need for the backlight...at least, all the displays that I have had from Sure Electronics have been that type

 

[GreenLeader]

Thanks
That shed some light on the subject for me!
Had no idea there were different types.