Encoder: updated README

Author: dplanella

Adafruit_BBIO/README.md

@@ -1,52 +1,47 @@
-# Adafruit_BBIO.Encoder module
+# Adafruit_BBIO.Encoder
 
-This module enables access to the Beaglebone Black enhanced Quadrature Encoder Pulse (eQEP) modules: eQEP0, eQEP1 and eQEP2.
-
-Initially based on the [PyBBIO](https://github.com/graycatlabs/PyBBIO/bbio/libraries/RotaryEncoder/rotary_encoder.py) rotary encoder code.
+This module enables access to the Beaglebone Black enhanced Quadrature Encoder Pulse (eQEP) modules: eQEP0, eQEP1 and eQEP2/eQEP2b.
 
 ## Prerequisites
 
-These instructions are based on a 4.4.x Linux kernel.
-
-In order to use all eQEP pins the BeagleBone must boot with the [cape-universal](https://github.com/beagleboard/bb.org-overlays/tree/master/tools/beaglebone-universal-io) enabled, and load the cape-universal overlay
-
-```
-enable_uboot_cape_universal=1
-```
+These instructions are based on:
 
-Notes:
-- It seems that the `cape-universal` cape _does only enable access to eQEP0 and eQEP2_. TBD: check how to load [`cape-universala`](https://github.com/cdsteinkuehler/beaglebone-universal-io/pull/30)
-- An alternative option to the `cape-universal` overlay would be to load one of the [dedicated eQEP overlays](https://github.com/Teknoman117/beaglebot/tree/master/encoders/dts). 
+- Linux kernel: 4.4.x or later
+- `bb-cape-overlays` package: version 4.4.20171120.0-0rcnee1~stretch+20171120 or later
+- `bb-customizations` package: version 1.20171123-0rcnee0~stretch+20171123 or later
 
-### Install/upgrade the latest Device Tree overlays
+It's recommended to run the following command to ensure you have the latest required packages:
 
 ```
-sudo apt-get upgrade bb-cape-overlays
+sudo apt upgrade bb-cape-overlays bb-customizations
 ```
 
-### Load the universal cape
+In order to use all eQEP pins the BeagleBone must boot with the [cape-universal](https://github.com/beagleboard/bb.org-overlays/tree/master/tools/beaglebone-universal-io) enabled, and load the `cape-universal` overlay.
 
-If it doesn't already contain it, modify the `/boot/uEnv.txt` file to contain this line: 
+This is the default, thus **no further steps are initially required to use eQEP0 and eQEP2**. Simply double-check that the following line is present and not commented out on your `/boot/uEnv.txt` file:
 
 ```
 enable_uboot_cape_universal=1
 ```
 
-Notes:
+Note: Some older documentation recommends using the `cmdline` and `cape_enable` options instead. They are meant to load deprecated kernel-based overlays and it's not recommended to use them. Use the new way of [loading overlays via uboot](https://elinux.org/Beagleboard:BeagleBoneBlack_Debian#U-Boot_Overlays) instead, as instructed above.
+
+### Enabling additional eQEP modules
 
-- Some older documentation recommends using these two lines instead. They are meant to load deprecated kernel-based overlays and it's not recommended to use them. Use the new way of [loading overlays via uboot](https://elinux.org/Beagleboard:BeagleBoneBlack_Debian#U-Boot_Overlays) instead, as instructed above.
+The `cape-universal` overlay will enable access to the eQEP0 and eQEP2 modules. As it does not expose pins that are shared with the HDMI interface, eQEP1 and eQEP2b will **not** be available.
 
-  ```
-  cmdline=cape_universal=enable # Plus some other options
-  ```
-  ```
-  cape_enable=bone_capemgr.enable_partno=cape-universala
-  ```
-- TBD: check the overlays that are currently loaded
+To disable the HDMI interface and gain access to the pins and peripherals that share its pins, comment out the following line on the `/boot/uEnv.txt` file and reboot:
+
+```
+disable_uboot_overlay_video=1
+```
 
 ## eQEP configuraton
 
-Note: if either eQEP1 or eQEP2b are used on the Beaglebone Black, video must be disabled, as their pins are shared with the LCD_DATAx lines of the HDMI interface.
+Notes:
+
+- If either eQEP1 or eQEP2b are used on the Beaglebone Black, video must be disabled, as their pins are shared with the LCD_DATAx lines of the HDMI interface.
+- eQEP2 and eQEP2b are the same module, but with the alternative of accessing it via two sets of pins. These are mutually exclusive.
 
 ### eQEP0
 
@@ -91,7 +86,12 @@ $ config-pin P8.41 qep
 $ config-pin P8.42 qep
 $ cat /sys/devices/platform/ocp/48304000.epwmss/48304180.eqep/position
 ```
+
+## Credits
+
+Initially based on the [PyBBIO](https://github.com/graycatlabs/PyBBIO/bbio/libraries/RotaryEncoder/rotary_encoder.py) rotary encoder code.
+
 ## Further reading
 
-- [Beaglebone encoder inputs](https://github.com/Teknoman117/beaglebot/tree/master/encoders)
-- [Beaglebone eQEP overlays](https://github.com/Teknoman117/beaglebot/tree/master/encoders/dts)
+1. [Beaglebone encoder inputs](https://github.com/Teknoman117/beaglebot/tree/master/encoders)
+1. [Beaglebone eQEP overlays](https://github.com/Teknoman117/beaglebot/tree/master/encoders/dts)