Sunday, 1 January 2012

Update on the touch monitor

This is tantalising... I found some data on driver chips used on these low-cost monitors and some of them have an I2C connection for sending pixel data directly to the screen. This may be to allow text or graphics overlay. Anyway the chip on my 7" screens is an AR05C-LF and there are millions of these in stock in the far east, but I can't so far find a data sheet for this chip or its sibling the AR05CA-LF.

Being able to send digital pixel data via I2C directly to the screen would be, well, brilliant.

5 comments:

  1. Hi Glenn, any luck on the AR05CA-LF datasheet? I have two 7" TFT screens ripped from a car DVD player kit with that chip on. I have also been looking for a spec sheet. Regards, Lars

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  2. Hi Lars. No luck so far on the datasheet. I'd love to know what the I2C does. Someone suggested setting up a test rig to send a sequence of I2C data to the monitor and see what happens. Probably not a bad idea, so I might set up my Arduino to do just that.

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  3. Lars and anyone else. I am going to try connecting an Arduino running an I2C 'sniffing' routine to at least see if the I2C connection does anything and try and get its base address on the bus. It might be possible then to figure it out by sending data in sequence to see if anything happens on-screen. If I get anywhere with this I'll report my finding. G.

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  4. I have the same screen and the same problem. No data on LCD.

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  5. Philip, if I get a chance to do an I2C scan on my LCD I will share anything I find. Should be very easy to find the address on the I2C bus, but figuring out any instructions would be a long process of trial and error. My workshop is too cold just now (-2 Celsius!) to get any work done.

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