I want to turn on LEDs on a hat from a signal on my hand using accelerometers ideally wirelessly. Sensor and LED will be using bluetooth.
How can I make this project? the tutorial given to me is to connect lilypad to mobile using bluetooth.
If I understand correctly, the sensor in my hand needs a bluetooth transmitter, and the microcontroller on my hat, needs a Bluetooth receiver. Both systems need its own batteries.
Is the module available a transmitter/receiver? Do i need to get two microconntrollers (one sending sensor signal, one receiving signal and turning leds)?
You are correct in that in order to send sensor data using bluetooth you will need a microcontroller on either end, as very few sensors speak serial in a way that can be transmitted easily over bluetooth.
We have a great guide on how to use the HC-05 bluetooth modules to send serial data over bluetooth
As for microcontroller choice, since you are looking for a wearable application a good starting point would be the Adafruit GEMMA as it features a battery input, and is small and rounded for a comfortable wearable. Adafruit has a great tutorial on how to use hardware UART, which is one way of sending data to the bluetooth module.
Another possibility to consider is using conductive thread by sewing the connection between the hand and the hat into the sleeve of a shirt. This would be a lot easier than connecting it wirelessly, but I understand it may not work in your particular situation
Your project sounds interesting and I hope we can help you get it off the ground!
Hi James thank you for your reply!
Lets say I want also to turn on leds on pants. Would it possible for two different BTE receivers (hat & pants) to connect wirelessly to a single transmitter (hand) ?
HC-05 modules are very easy to implement in a 1-1 master and slave topology, however, they are unable to act in a mesh topology in order to have 3 devices speak to each other seamlessly. A crude way to achieve this would be to have the master (the hand unit for instance) disconnect from one device (i.e. the hat) and connect to the other (i.e. the pants) in order to send the data to each.
Boards such as the ESP32 Can use BLE or WiFi to send data and are capable of acting in a mesh. I found a page in the ESP32 documentation that gives an example of mesh networking with BLE
Generally, 1-1 communication can be very simple, but 1-many or many-many is usually more complex to implement.
I hope this gives you some idea of the options available