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+--- Thread: Copying an image to HP Prime via USB (/thread-20363.html)
Copying an image to HP Prime via USB - matalog - 08-22-2023 10:16 PM
I have been experimenting with USB transfer to HP Prime from Arduino recently and tried out this idea to see how fast I could transfer data. It could still be a little bit faster, but this is getting close to the full rate.
I wrote a program that extracts the RGB data from a 320x240 pixel image and then outputs the data as text that I can import into an Arduino program. I then store the data in PROGMEM (Flash) memory on the Arduino and transfer that to another Arduino (via 250,000bps serial) that can communicate via USB HID with the HP Prime (because the Arduino Leonardo, which can commmunicate via USB does not have enough flash storage to store the entire image I had to use an Arduino Mega to store on).
It could be a tiny bit faster, but not a lot. For example, running a program on HP Prime which only fills each pixel with black takes a few seconds itself, and obviously this program needs to assign the data to the Red, Green and Blue channels on the HP Prime.
I will be experimenting with reading from SD Card next, and will show the results when I get around to it. The data transfer rate is not so bad considering that it is running in BASIC on the HP Prime, and there is hope for some other methods to increase the speed in the future.
RE: Copying an image to HP Prime via USB - Insoft - 08-23-2023 02:02 AM
I found your video of the image transfer via USB very interesting and educational.
The transfer speed not half bad it reminded me of the old 8-bit microcomputers like the ZX Spectrum , C64 loading splash screens then the game.