BeagleBoard VGA adaptor

I spotted this simple circuit for attaching a VGA monitor to a BeagleBoard. That could be handy for those who only have analogue TFTs or CRTs. It works by building a simple digital to analogue converter for the parallel LCD outputs.

Out of interest, what’s the likelihood of RISC OS’ video timings being suitable for an analogue monitor in this way? If necessary, could they be tweaked with *LoadModeFile run from the serial console? (Does the Beagle video driver use that infrastructure?)

Yes, we still use monitor definition files to set the display timings. The only problem you’re likely to have getting the OMAP3 to work with a VGA/CRT monitor is that until OMAP3 ES3.1 was released (sometime last year – I’m not sure when) the porch & sync timing registers were quite small, stopping you from using standard VGA mode timings. This generally isn’t an issue for LCD/TFT monitors since they can often work with very small porch/sync values, but could be an issue if you try connecting a CRT display where larger values are required.

I went for an inexpensive Xerox 17” LCD monitor in the end, and I’m pleased with it:

http://www.aria.co.uk/Products/Displays/Monitors/TFT+17/17%22+Xerox+XA7-17i+TFT+Monitor+Glass+Screen?productId=37591

If you do the same, beware: it has a captive cable with a DVI-I plug on the end. Most HDMI-DVI adaptors are to a DVI-D socket, which won’t accept a DVI-I plug. There are some HDMI to DVI-I; I got one on eBay for under GBP4.

I went for an inexpensive Xerox 17” LCD monitor in the end…

For info, this DELL 1704FP 17" works OK (although I did have to return it as the power button had become dislodged – you get what you pay for s/h I guess).