So, I had an idea about making a set of wearable, Arduino-powered bracelets that would be used to play “outbreak” tag.
The idea is there are 3 types of bracelets:
- 1 Patient Zero Bracelet: This would be indicated by a red LED and it would only emit an “infected” signal
- 1 Doctor Bracelet: This would be indicated by a green LED and it would only emit a “cured” signal
- 6+ Citizen Braclets: These would be indicated by a blue LED, and emit a “healthy” signal to start, but they’re capable of changing. If they get too close to the Patient Zero bracelet (or an infected Citizen) they would switch to “infected” and would then turn red and start to emit that signal. Getting close to the Doctor will convert them to “Cured” status with a Green color and short period of immunity, before they transition back to a blue “Healthy” state (and susceptible to being infected again).
I’m a total newbie with Arduino, but I’ve had some fun with programmable LEDs. I’m not sure how to handle the sensors/signal detection - any advice on that? Also, what are people’s thoughts on the best way to keep sizes small? They’re intended to be worn by my kids. Thanks in advance for any advice!
ESP8266 are small and programmable as/with arduino. Signal strength cn be used for proximity - and basicly that's it. 3 LEDs + Resistor are easy to handle. Powersupply could be tricky, I'd use a buck converter (step up or step up/down) for 2xAAA or 1x9V blockbattery.
Signal strength cn be used for proximity
There are many Forum Threads which suggest that that won't work
Ah, I should have clarified - the intent would be for this to be played outdoors and out of reach of any consistent WiFi signal...so I was wondering what would be the best wireless communication alternative? I figured triggering a sensor within a ~2ft proximity would be a good distance
2 feet? Infrared, sound, NFC, RFID tags … most things are not omidirectinal and best yo can get is yes/no. anything that can get reflected will increase range. anything hindering direct line of sight will reduce range. sound is the least to be shaded (travels around objects), but probably undesireable. wifi that near is problematic, but you could shield the antenna
I think "close" could be "touching or almost touching" with IR LED's like the TV remote. That makes it easy for the Arduino to transmit the required signal continuously without chewing up too much battery power. A ring of transmitters and receivers (maybe 5-8) will make the bracelets acceptably non-directional.
But "infecting" someone by being 6 feet away in an outdoor setting is actually much harder than you think. You need a directed IR beam like a gun or you need a groundbreaking advance in the science of radio waves.
That 2 ft would be sensor to sensor proximity, not person to person. Big difference, especially for the infecting part which, like in the real world, usually goes "automatically" - without active interaction between two individuals, just being close to one another. The problem is that this is technically very hard if not impossible to do.
The doctor's tag could feasibly be RFID, with the doctor's tag to be held close to the patient's tag. It's a nice simulation of the reality where a doctor needs to actively interact with the patient to cure the disease.
Maybe you could implement the "infecting" part in a different way - given that this is only for a game.
Suppose everyone has a reasonably omni-directional IR LED (or a few few of them as suggested earlier). Suppose also that everyone has a receiving photo-diode that is made somewhat directional by being at the bottom of a small tube.
Then suppose that the transmitter only transmits an "infect" message occasionally. And, a receiver needs to detect a number of "infect" messages before it reacts.
The transmitters could send identifiable messages and the receivers could react more strongly to messages from multiple "infected" people rather than all messages from the same person.
Of course this does not rely on distance except to the extent that the brightness of the transmitting LEDs could be kept low.
And the logic I have suggested could be modified in lots of different ways - I just want to put some ideas into circulation.
Neat idea. IR is probably the easiest comm technique, and can have sensitivity adjusted pretty easily with mechanical stuff (tubes, filters,etc.)
There’s a couple devices that do something similar: Disney’s magic paintbrushes and a bunch of the ”blinkie kits” from 2dkits.com