Add orange to epd7in3e

[missionfloyd]

I noticed that palette index 4 is skipped for Spectra 6 panels.

e-Paper/RaspberryPi_JetsonNano/python/lib/waveshare_epd/epd7in3e.py

Line 183 in ecdd8cf

pal_image.putpalette( (0,0,0, 255,255,255, 255,255,0, 255,0,0, 0,0,0, 0,0,255, 0,255,0) + (0,0,0)*249)

So I tried sending 0x04, and it turns out it's actually capable of displaying orange.

(Code that created this image)

buf = []
for i in range(7):
    buf += [(i << 4) + i] * int(width * height / 14)

epd.display(buf)

This fills in the missing slot with orange. I've only done it for python because I'm not as familiar with how the C libraries work.

[psiegl]

That is pretty cool! Thanks for the hint, will try it as well. Which Spectra did you use?
EDIT: tried on a 13.3' Spectra 6, seems to not work on this one.

[missionfloyd]

I have the 7.3 inch
https://www.waveshare.com/product/raspberry-pi/displays/e-paper/7.3inch-e-paper-hat-e.htm

[psiegl]

So, I tried to use orange on a 4.0', 7.3' and 13.3' Spectra 6 EPD.
7.3' -> looks like a charm
4.0' & 13.3' -> overall picture becomes more grayish not nice.