I'm not 100% sure if those ebay serial LCDs will do the job now that I think about it...
My plan (to be implemented shortly) is to have the control buttons on the screen module, and button events sent back down the serial line to the AP to process.
The ebay modules look like they have provisions for a keypad matrix, but I haven't read through the datasheet to work out how the key presses are handled.
The fact that they support a keypad makes me think there must be a way of transmitting them, unless it's only supported by the I2C interface....
The other advantage of my LCD module is that it adds a bunch of analog and digital inputs that can be logged as well, and some digital outputs that could be used as progressive shift lights, gear indicators or warning lights etc - and a PWM output in case I get around to faking a VSS signal from a GPS input
With a bit of extra coding, a wideband controller could be directly connected to the display (either as 0-5v analog signal, serial, or I2C) and run as a standalone WB display without needing the AP being connected.
but being able to use all off-the-shelf bits might be worth sacrificing these extra features, so will see if I can support both display types.
I could probably build the displays like mine for under $50, but it's starting to turn into an expensive-and-dodgy hack, which goes against my scottish heritage
I just was this while cruising ebay -
http://www.ebay.com.au/itm/2004-LCD-Dis ... 0289036456 - looks perfect (and uses my good friend the CP2102 usb UART), but doesn't support buttons. The PIC that drives it has a couple of unused inputs, but would require a firmware re-write to make use of them and I couldn't find the source published anywhere - so it's close, but no cigar
The WL-520gC doesn't have USB support, so isn't going to be much use as a logger
It should be possible to convert a gC to a gU (see
http://mightyohm.com/files/wifiradio/Je ... L520gU.pdf) but probably isn't worth the hassle considering there isn't much difference in price.
Also, the LCD will need to be a 20 char x 4 row (commonly referred to as a 20x4 or 2004) - the '1602' displays are 16 chars x 2 lines, so those ones won't do.
I'm setting up a repository for the broadcom OpenWRT packages I've had to build (mainly XML and serial modules) and will post the URL once it's ready in case anyone wants to check out where it's up to, but still a long way to go
The TP5 wireless integration is also being worked on. It won't be ready any time soon though.
I know there's definite interest in the this setup 
