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What I want is a chip that can be connected to an MCU over an UART which outputs textit receives over VGA or composite in text mode to a display in monochrome or color and optionally accepts VT100 escape-sequences (or something similar) to format text. Optional graphic mode would be nice.

I already asked this question on reddit but I did not get many answers.

Personally I found the TVT-KVGA20, but its resolution (50×18 characters) is a bit too low. Someone on reddit suggested the µVGA, which looks really sweet but is not quite a single-chip solution.

Are there other options?

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Many fast microcontrollers can do this or you could 'easily' implement an FPGA solution. Enough such solutions exist that it's just a matter of finding the one that best suits. I imagine that FPGA vendors offer VGA implementations as library items.

A typical example of a minimalist microcontroller based solution is the "Maximite" which uses a PIC32 processor.

The colour Maximite uses a PIC32 + Colour Maximite circuit diagram here
The maximum resolution is below what you would desire BUT is essentially a function of available memory and processing resources.

Colour Maximite home page
Building ...

Monochrome VGA - Monochrome Maximite page here

enter image description here

See above page for more details, but they say:

  • The video is generated by a standard SPI peripheral within the PIC32 chip. This is continuously fed with data by the DMA circuitry which reads a section of memory and feeds the data to the SPI peripheral so that there is a constant stream of ones and zeroes being clocked out on pin 6 of the chip. These bits represent the video signal for a horizontal line with each bit being a pixel. The beauty of this scheme is that it happens independently of the CPU which only needs to write the required pixel data to the allocated section of memory and service an interrupt for the horizontal sync pulse.

    The technique is described by Lucio Di Jasio in his book "Programming 32 bit microcontrollers in C” which is well worth reading if you are interested in learning more about programming for the PIC32.

    An important part of the circuit is R5 which feeds the horizontal sync pulses back to the SPI peripheral so that the start of the data stream is synchronised to the pulse. This removes any jitter that may be caused if the CPU was used to start the data stream and results in a very steady image on the screen.

Choose a suitable main processor and you have a zero added chip solution.


Undergrad project VGA in FPGA

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Besides the chip, even in "one chip solution" there are always more parts in the schematic - power filtering, input/output signals shaping, protection, connectors etc, etc.

Anyway, I wanted to point to several software solutions that generate VGA text/graphics directly from the AVR controller outputs, using only 5..6 resistors as external components.

Two (of many) examples are here and here.

Example view:

enter image description here

Breadboard view:

enter image description here

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The Parallax Propeller chip makes a very nice single-chip serial-to-VGA translator. There are many examples of how to do this on the web.

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