Experimenting with the PIC24FH128DA210

[Majenko Technologies]

I have finally got hold of some of these chips - actually the PIC24HJ256DA210 - and very nice they are too.

I have managed to fool the GPU into driving a VGA screen - it required the usual resistor/diode pair on the RGB lines to get it to 0.7V, along with a buffer chip to disable the RGB lines during the blanking periods - something the chip doesn't do itself, but it provides a signal so you can do it yourself in hardware. I have used a 74LVC8T245 chip, because it can cope nicely with the 25MHz pixel clock. I tried with a simple MOSFET per channel before, but it corrupted the signal too much,

It's running at 640x480 with 2bpp (4 colours, at the moment black, red, green and blue, although you can select any combination of them) with no external memory needed. Here's some shots of it driving my 19" iiyama TFT screen.