Loona Pet Bot Charge Station Light

As probably all Loona owners already know, in order to find the charge station Loona needs to see the logo on the mast at the back of the charge station in order to navigate and reverse onto the charge station.

This clips onto the back of the rear vertical mast, and uses a 3.3v single LED / Heatsink that can be found on many sites.

But you cannot power this directly from 5 volts USB as it will get VERY hot and immediately melt the mount.

So it requires either current limiting resistors or a PWM controller which can be in the form of a LED PWM controller (also found on many sites) or, as I did using a M5 Atom Lite or Stamp and ESPHOME.

The advantage of using a ESP device, is that you can control the brightness and switch it on and off remotely using the web interface, home assistant automation, or by defining a schedule when the illumination should be on / off.

You could also create an automation that checks if Loona's ip host is alive, and only power on the LED when the host is alive.

I am driving the LED directly from the ESP pins, and in order to get enough current I needed to parallel 2 of the GPIOs and PWM them both. 

I won't go into all of the fine details, most should be self explanatory or obvious from the images, basic electrical / soldering skills are required.

I used a JST XH (2.54mm) 2 Pin Male & Female connector, and a small piece of Vero board to mount the connector, and wired it using some wire from a prototype wiring pen, or you could just use thin gauge wire or copper wire.

It also needs an insulating ring to prevent the contacts from the JST connector from shorting out onto the LED's heatsink, that can be seen in the photo.

The version in the picture is slightly different, as I modified the retaining cap to screw down with 4 small self tapping screws.