Despite the popularity of digital video outputs due to the speed and uniformity of digital signals, analog video outputs are still a popular choice for many users. Notably, VGA analog signals offer advantages like dividing signals with distribution amplifiers without any complexity. What’s more, VGA is compatible with various advanced components using a 5-wire input. Additionally, analog video signals are compatible with older devices that that lack digital video inputs and outputs.
The new Raspberry Pi Pico operates at a frequency of up to 133 MHz, which is on the higher side when compared with Arduino microcontroller units (MCUs) which run at 16MHz. VGA signals require a higher frequency, as the VGA pixel clock needs a minimum 25 MHz frequency. Hence, the Raspberry Pi Pico is capable of generating analog VGA signals.
Pimoroni’s Pico VGA demo board comes with a VGA output and an SD card slot for using the Raspberry Pi Pico’s VGA signal capabilities. It also allows users to take advantage of some interesting functions of the RP2040 microcontroller such as generating a solid VGA output without the operation of the CPU. However, Robin Grosset’s video explains a simpler way to generate VGA signals.
As Robin Grosset’s video reveals, the only components necessary are a VGA connector, resistors, and some jumper wires for building a system capable of generating a VGA output from Raspberry Pi Pico. The video gives detailed information on the connections of the resistors and the values associated with them. Raspberry Pi Pico comes with 5-bit DACs for RGB signals which allows for a combination of 32,768 colors. The software support is used from the pico-playground GitHub repository.
Furthermore, the third chapter in the official documentation of Hardware Design with RP2040 opens up the scope of many VGA-based applications. For more information, watch the complete YouTube video by Robin Grosset.