Tell HN: I made an Alien UFO scavenger hunt for son's 10th birthday party
I made an alien crashed UFO scavenger hunt for my son's 10th birthday party.

It was based around esp32 chips and bluetooth devices and old AM radios. I wrote alot of esp32 code for it and it all took way too long for me to implement but it was fun.

Before the hunt begins......

The idea was it would be played in the local park at night time. As we are driving to the park, I turn on the AM radio in the car. At a certain time, I push a bluetooth LE button which activates an ESP32 to play a sound clip over the car radio saying "Emergency! We interrupt this broadcast - an alien spacecraft has crashed! You must find it and rescue the aliens!"

How the hunt works:

The kids are each given a BlueTooth BLE button to search for crashed UFO parts and aliens and weird alien technology. The kids search the park with the BLE buttons and when they are near a treasure, the lights start flashing and alien messages are played through the AM radio. https://www.aliexpress.com/item/1005004985105723.html At each treasure location hidden in the dark there is an esp32 connected to a string of led lights cut from Christmas tree led light string, and also connected to an AM radio. The esp32 is running a sketch using Neil Kolban's BLE scanner, searching for the device ID of the BLE buttons. When the BLE buttons are in range of the hidden Alien UFO parts, (about 15 feet) the esp32 blinks the leds and plays sci fi audio clips using an AM radio signal generator http://bitluni.net/am-radio-transmitter/

The missions:

The scavenger hunt starts in the middle of the park. I used an old briefcase and inside it are six mission briefing envelopes. Each mission briefing envelop contains an audio greeting card playback device, upon which I recorded a mission briefing for each of the treasure hunts described below. The audio playback devices are light sensitive so they start playing their sound when they are pulled out of the mission envelopes: https://www.aliexpress.com/item/32930873811.html

Treasures to be found include:

Treasure #1 -24 glow in the dark aliens https://www.thepartycupboard.com.au/products/glow-in-the-dark-aliens Aliens are hidden throughout the park, their locations marked with these tiny individual battery powered leds https://www.lightinthebox.com/en/p/6pcs-led-balloon-lights-mini-luminous-ballon-lamps-for-paper-lantern-bar-christmas-wedding-party-decoration_p7574222.html

Treasure #2 - https://www.aliexpress.com/item/1005004767224293.html flashing led light energy cubes. When the kids bring them back to base they are dropped into a nuclear reactor's water (i.e. a bucket with water in it) and they activate, flashing. Radioactive UFO parts are covered with glow in the dark sand https://www.aliexpress.com/item/1005004628971176.html

Treasure #3 - glow in the dark spiders https://www.aliexpress.com/item/1005002863141919.html these are the enemies of the aliens and have followed them through space to earth. The kids must capture the spiders, and must eat the spider eggs (jaffa orange round chocolates) so the spider don't breed any more.

Treasure #4 - helium balloons, which the aliens will use to return to their mothership in orbit. At the end of the treasure hunt the kids attach the aliens to helium balloons and return them to space by releasing the balloons.

At the end of the mission the kids have to drop all the treasures into an old rice cooker which I told them was a nuclear reactor. I had put dry ice in it. Then they had to pour water on top, releasing clouds of mist from the reactor, strangely lit by the flashing ice cube leds. This signalled that the kids should release of the balloons carrying the little glow in the dark aliens and battery powered leds, sending the aliens back home and ending the adventure.