document display types

software/firmware/doc/source/about.rst

@@ -2,3 +2,38 @@ About
 =====
 
 EPDiy is a driver board for e-Paper (or E-ink) displays.
+
+Display Types
+-------------
+
+The EPDiy driver board targets multiple E-Paper displays.
+As the driving method for all matrix-based E-ink displays seems to be more or less the same, only the right connector and timings are needed. The EPDiy PCB features a 33pin and a 39pin connector, which allow to drive the following display types:
+
+ED097OC4
+~~~~~~~~
+
+The ED097OC4 was the original target of this project. It is an 9.7 inch screen, with a resolution of 1200 * 825 pixels (150dpi).
+It is fairly available on Ebay and AliExpress, for around 30$ to 35$. 
+There is also a lower contrast version (ED097OC1), which was not tested and shoudl not be ordered.
+
+.. image:: img/ed097oc4.jpg
+
+ED060SC4
+~~~~~~~~
+
+This is a 6 inch display, with a 800 * 600 resolution. With 150dpi as well, it has about half the total display area of the ED097OC4.
+To connect this display, the 39-pin connector on the back has to be populated.
+It is also the display a lot of experimentation was done with (see Thanks To), so there are alternative controllers available.
+Besides the obvious difference in size, this display is cheaper (~20$) and also refreshes slightly faster than the ED097OC4.
+
+.. image:: img/ed060sc4.jpg
+
+ED097TC2
+~~~~~~~~
+
+Information on this display should be taken with a grain of salt. One of the displays I ordered as ED097OC4 came as ED097TC2,
+and upon testing it also exhibited noticably better contrast and a more responsive electro-phoretic medium. 
+The ribbon connector looked like a ED097TC2 as well, or like the `9.7 inch screens offered by Waveshare <https://www.waveshare.com/9.7inch-e-Paper.htm>` (which is sold for a lot more).
+If you are on the lookout for such a display keep in mind the authenticity of my sample is disputable and resolution and connector type should be double-checked.
+
+.. image:: img/ed097tc2.jpg