Tips for regularly updating CP7 screen


I have been developing a communication process on my Fez Cobra II for sometime now which has quite a lot going on inside including buffer levels etc.

I’m now considering attaching my CP7 screen module to the device to give me a display of what is going on inside the app. My previous experiments with this screen were using Glide and were not particularly efficient. Obviously my board is already quite busy and I would like to reserve as much processing power for the communication as possible.

My question to the forum is does anyone have any tips for efficiently using the CP7 screen? Should I be using Glide or should I be talking to the device directly? Can I update small parts of the screen at a time? What is the best way to clear an area of the screen so you can overwrite text that was there?

Any help would be well received.

The most efficient way should be painting to the display bitmap directly.
To clear an area you need to draw a filled rectangle first.
This is what glide does internally as well, but with more overhead of course.

This is more or less how I use the N18 on my MedusaMini.
It’s just not writing to a buffer but sending blocks of pixels over SPI.

If you want to have a console like output, there are several solutions on CodeShare. Search for console and you will find several implementations.

Hi Reinhard,

Thanks for the advice. I’ll check out some of the examples as I haven’t looked at these yet.

Is it possible to detect whether the CP7 is attached?

Not sure about the RGB sockets, probably not, but the I2C interface of the touch should only answer if display is attached.