Read pixel data from LCD

In my PIC projects (written in C) I have used similar LCD panels as per the DISPLAY_2. I draw a selection of bitmapped images with such as an analogue meter needle/icon over the top of the graphic (which is static). The meter needle moves depending on ADC values and to obtain maximum speed by saving erasing and redrawing the background bitmap each time, before I draw the first instance of the needle, I read the values of the pixels on the screen (of where the needle will be drawn), save the values in an array then draw the needle/icon.

In the next high loop I first draw the above saved array pixel values to erase the needle/icon, then save the pixel values of where the next needle will be then draw the new needle… and so on.

I am therefore only ‘erasing’ the last shape/icon/needle and not the whole display. This smoothed out the response.

Question: is there a method in micropython to read a pixel at a specific x/y position?

Thanks for looking

Hi SteveA,

I got an email telling me you had opened a new topic but from the skim read I did of the email I didn’t realise that we were doing something very similar, you a representation of an analogue meter (dB, Ohm C or V?) and me trying to produce a movement meter as in the Predator movies / Halo Xbox game essentially a 180 degree radar screen.

I was just going to several lines of different intensity (of green) to show movement with the set iterating from left to right leaving bright spots where the movement occurred.

Reading the display seems hard work?

Good luck with it, I’m starting from scratch and still got it to do in Python. It’s not going to be as fast as C/C++ but I’ve read that Python is very efficient in handling strings, I might clock it with ticks and we can compare if I ever get it to work?

I’ve got the static bit and working on the moving line

Hello Kids Taxi, that’s interesting! We will have to compare notes over a cuppa one day!

I program in C for the RPI but have not, as yet, been able to set up the SDK, etc, to program the Pico in C and so I have been experimenting using Micropython, hence my frequent pleas asking where the in-depth documentation is stored.
All the best

Hi SteveA,
Well today is your lucky day, Ive found the gold mine. Check this out its a modification of a modification of the Slow Display driver from Alibaba Express. You will need to go to the end of the topic as the interesting bits are halfway down to the bottom of the topic.

Thank Kids Taxis, that’s interesting and well spotted. I will study it.
I wrote my own C driver, graphics and font routines to use PICs with the Densitron DD-160128FC-2B OLED DIsplay, 160 x128 RGB, Driver IC = SEPS525F0A.
OLED displays are quite good regarding power vs brightness as there is no backlight as used in LCDs, however they can be pricey and hard to get. I am currently waiting for a batch.
All good and interesting stuff and I am slowly learning micropython bit by bit!