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Title: display on LCD monitor (VGA interface) Post by: mr_byte31 on February 13, 2018, 07:34:20 19:34 Hi All,
I am working on a small project for my friend and the challenge I have is to display a picture from microSD to LCD monitor ( my old computer monitor ). The monitor is 17 Inch. I don't think the reading from the microSD will be a problem but I have doubts that I can display on the monitor. the VGA interface will require high speed processing which is way from my AVR. any body have experience with VGA circuits that can help me? Title: Re: display on LCD monitor (VGA interface) Post by: solutions on February 14, 2018, 02:58:29 14:58 Something like this? http://tinyvga.com/avr-sdram-vga
Title: Re: display on LCD monitor (VGA interface) Post by: mr_byte31 on February 14, 2018, 03:54:55 15:54 Actually I am trying to use it for 800x600 pixels at 60 Hz
overclocking the AVR is not something good for long time operation Most of the ICs in this project are not available now. Title: Re: display on LCD monitor (VGA interface) Post by: DarthPic on February 14, 2018, 06:23:20 18:23 I hope it will help a little in your work.
Back in 2013 i made test on stm32f429 discovery board for output VGA. It worked very well , i give you here the graphics library i have do and the R2R DAC PCB + Schematic done with Proteus (the actual one). The tip was to remove the LCD from discovery board and use the external pins to go on the R2R DAC for get VGA output :D But if you like to stay on AVR MCU , just take a look on the parameters and timing i use in my library. My first test is here in 640 x 480 : https://www.youtube.com/watch?v=3GOEYUBZouA (https://www.youtube.com/watch?v=3GOEYUBZouA) Another one here : https://www.youtube.com/watch?v=gQznHo5hwaQ (https://www.youtube.com/watch?v=gQznHo5hwaQ) Cheers. Title: Re: display on LCD monitor (VGA interface) Post by: solutions on February 15, 2018, 02:02:58 02:02 Actually I am trying to use it for 800x600 pixels at 60 Hz overclocking the AVR is not something good for long time operation Most of the ICs in this project are not available now. You said you were displaying a picture, not video, off the SD card. With that dual port video RAM setup, you could run the AVR at 8kHz and still accomplish your goal. I also got the sense this was a one-off, so sourcing an old chip should be a non-issue. Title: Re: display on LCD monitor (VGA interface) Post by: mr_byte31 on February 15, 2018, 11:00:08 11:00 @DarhPic, thanks a lot . I will check this project.
@solutions. Yes it is a picture. I didn't say anything about video. do you find the ICs names on the internet? Title: Re: display on LCD monitor (VGA interface) Post by: bigtoy on February 18, 2018, 01:19:47 01:19 If it's a one-off, why not use a Raspberry Pi, and an HDMI-to-VGA adapter? The adapters are around $7 on ebay, and the Pi is also cheap and has a SD card socket on it.
Title: Re: display on LCD monitor (VGA interface) Post by: mr_byte31 on February 18, 2018, 10:32:57 22:32 Raspberry Pi, and an HDMI-to-VGA adapter will cost me $70
I was thinking about a cheaper solution. I never used PI kit before and I don't know how to program/configure it. it will be a new learning curve it to me. I will consider it as a solution but not for this project. Title: Re: display on LCD monitor (VGA interface) Post by: lou on February 18, 2018, 11:09:11 23:09 Look at Pi Zero... less than $10
Title: Re: display on LCD monitor (VGA interface) Post by: mr_byte31 on February 20, 2018, 06:01:08 18:01 Look at Pi Zero... less than $10 I didn't know about Pi zero. many thanks.time now to study how to use it :) |