I emailed Waveshare indicating my problem getting anything to display on the 2.13in epaper. They were VERY quick to get back to me, and suggested I try running the tests for another size, the 1.54in model, just to see what it did.
Turns out, that worked. So I started looking closer…
drwxr-xr-x 2 root root 4096 Sep 10 00:11 .
drwxr-xr-x 5 root root 4096 Sep 10 00:11 ..
-rw-r–r– 1 root root 2801 Sep 10 00:11 epd_1in54b_test.py
-rw-r–r– 1 root root 2657 Sep 10 00:11 epd_1in54c_test.py
-rw-r–r– 1 root root 2976 Sep 10 00:11 epd_1in54_test.py
-rw-r–r– 1 root root 2969 Sep 10 00:11 epd_1in54_V2_test.py
-rw-r–r– 1 root root 3756 Sep 10 00:11 epd_2in13bc_test.py
-rw-r–r– 1 root root 3020 Sep 10 00:11 epd_2in13d_test.py
-rw-r–r– 1 root root 3026 Sep 10 00:11 epd_2in13_test.py
-rw-r–r– 1 root root 3097 Sep 10 00:11 epd_2in13_V2_test.py
-rw-r–r– 1 root root 4006 Sep 10 00:11 epd_2in7b_test.py
-rw-r–r– 1 root root 3017 Sep 10 00:11 epd_2in7_test.py
-rw-r–r– 1 root root 3851 Sep 10 00:11 epd_2in9bc_test.py
-rw-r–r– 1 root root 3760 Sep 10 00:11 epd_2in9d_test.py
-rw-r–r– 1 root root 3822 Sep 10 00:11 epd_2in9_test.py
-rw-r–r– 1 root root 3981 Sep 10 00:11 epd_4in2bc_test.py
-rw-r–r– 1 root root 3147 Sep 10 00:11 epd_4in2_test.py
-rw-r–r– 1 root root 3859 Sep 10 00:11 epd_5in83bc_test.py
-rw-r–r– 1 root root 3154 Sep 10 00:11 epd_5in83_test.py
-rw-r–r– 1 root root 3981 Sep 10 00:11 epd_7in5bc_test.py
-rw-r–r– 1 root root 3147 Sep 10 00:11 epd_7in5_test.py
I had been using epd_2.3_test and the epd_2.3_V2 test, neither of which worked. After seeing it function properly on a couple of the 1in54 tests, I went through them all systematically. Turns out both epd_2in13bc_test and epd_2in13d_test work.
So I generated some red and black bitmaps, and using the example code as a template, pulled them in and displayed them.
What I love about epaper is that it doesn’t require power to display, only to change the display.
Now I’m looking at a 1500mah RPiZeroW-sized LiPo. I have other battery banks, but I like the idea of a low profile unit that can fit in a small pocket and maybe even be enclosed with the assembly. I was looking at this one…