From what I've seen so far, the LCD displays I've found are generally character-based. Are there any affordable (under £40) LCD displays that allow me to send pixels? Basically I want a graphical display, with graphs etc, not just text.
Is there such a thing in a simple-to-use package, or will I have to stump for a £50+ device like these ones from Active Robots?
Maybe something here will strike your fancy:
Ooh hello 
Some of those look good. I'll keep digging and try to find a UK supplier for some of those, at least I know what to search for now.
Thanks.
You're welcome. Good luck, and have fun!
Before I start looking too deeply at supplies, is there anything particularly Arduino-specific to watch out for? What worries me is that some specify that a certain amount of buffer RAM is required.
Ignore that last - it's lazy and RTFM-worthy I'll dig about here and on the interwebs a bit first
I've been looking at the Graphical Display section of SK Pang, and they have a couple of interesting devices there that might fit the bill.
There is one, the "Graphic LCD 128x64 STN LED Backlight", which claims to "utilize the extremely common KS0108B parallel interface chipset".
The other is the "Serial Graphic LCD 128*64 (ST7565/67 ctrl)".
Are these going to be relatively simple (whatever that might mean 
) to get going on my Arduino Uno? From what I've seen on the forums, the KS0108B will eat up a LOT of pins (13), but I might be able to mitigate that with some serial-to-paralel schenanigans.
They also have a "Graphic LCD Serial Backpack" that might solve that pin problem for me, by exposing a simpler serial interface.
Any advice, tips, clues or corrections greatfully accepted
(PS. I assume it's okay to post loads of links to a commercial site like this, if it's in specific context of questions? If not give me a smack and I'll desist in future)
PS. I assume it's okay to post loads of links to a commercial site like this, if it's in specific context of questions?
It is, if you are posting in the appropriate section of the forum. This section is for discussion of products and services that members can provide. Since this is not the context of your postings, they belong in Project Guidance.
A serial LCD will be the easiest to connect to the Arduino. One wire for power, one for ground, and one wire to send data to the LCD. If you need to get data from the LCD, and it provides any mechanism for doing that, a 4th wire is needed. The data out and data in lines connect to digital pins - 0 and 1 if you want to use Serial to talk to it (not recommended) or any two other pins and use NewSoftSerial to talk to it.
Aha, I'll put my purchasing q's in with my project stuff next time then
I've stumped up for one of the serially-interfaced displays, and I shall report back how I get on when it arrives!
I bought a nice SparkFun Graphic LCD Serial Backpack and a Graphic LCD 128x64, which excitingly arrived yesterday.
I got the backpack attached to the screen, and connected to my Arduino, and so far have a nice bright blank screen, but no response to serial comands
Ran out of time then, so no idea what I've got wrong yet. I rebuilt my robot a bit to make the arduino extractable so I can play with the screen in isolation. For now assuming I've done something wafty, so will cross fingers and have another stab this evening. Expect questions 
I think it's something to do with using SoftSerial, at 9600, when the backpack defaults to 118000, so I'll tinker about with configuring it using the real serial io pins to talk at 9600.