Best to assume that the conductor colours of the 6p6c cable will be random, so don't rely on wire colours when hooking up!
There is also one general purpose diode -- pretty much anything will do there, it just protects the telescope from current back-feeding from the USB connection of the ESP32 board.
Two 50Kohm resistors are used as pull-ups on the TX and BUSY lines. Some mounts work without these, but they should really be present in all cases.
The diagram shows three optional resistors that exist only because I am paranoid. This design does not require them. They provide current limits in case something gets wired incorrectly.
There are two optional WiFi-enable switches: one controls the ESP32 WiFi, the other controls the built-in WiFi on a Celestron Evolution Telescope mount. It is useful to be able to switch WiFi completely off when using the hand-controller, to save battery power and minimize WiFi pollution.
Note that if the switches are not installed, then both WiFi will be OFF by default. You can either tie the D15 and D4 pins to GND, or modify the Arduino sketch to enable WiFi by default.
The latest design also now includes an optional WiFi-settings Reset switch, and an optional WiFi-Mode switch for selecting between "direct connect/SoftAP" (default), and "use an existing Access Point". These are the same switches as on the Celestron products.
One can also add a GPS switch (not shown) for the GPS module: just insert it into the power lead (red/violet) of the BN-180, to cut power directly when desired.
The Arduino "sketch" (aka. "program") that runs the entire project is available here: esp32_wifi.ino (always the latest version).
For initial test instructions see here.
To continue, click on the right-pointing little blue arrow near the top left.