I am working on a project that will output either NTSC or PAL video.
The video is mainly text (color and Hebrew text) on top of a background image (that I need to download to the microcontroller).
The board has a UART input and a PAL/NTSC output and according to the UART input different text is displayed (very slow rate).
If it wasn't for the background requirement I would probably try to implement the many hobby projects using a resistor ladder to output composite video using a simple microcontroller but that is not an option.
I did not find much information on making a cheap and relatively easy solution on the internet so what components would you recommend for this circuit?
Best Answer
Actually, using a suitable micro you could get 12-bit colour and reasonable resolution.
For example, the STM32F407 has two 12-bit DAC's that can be continuously loaded by DMA to generate composite video. Allocate a section of RAM (it has 200kB) to be a frame buffer, fire up the DAC and DMA and off you go - reasonable video from an MCU for zero CPU cycles. You can get an STM32F4Discovery board for US$15, including an on-board debugger, and the free Coocox IDE is pretty reasonable for what you pay. For another $45 or so you can add a base board with an Ethernet port and an SD socket for image upload.
Just a thought.