Looking for advice for a proof of concept.
We have a product line that has an hydraulic cylinder that we will attach a distance measuring sensor. (0 - 5vdc)
I want to display this on three parallel WS2811 strips so it has 10 Segments 3 leds wide to display to the operator the position of the hydraulic cylinder. Also it has to have a relay or P Channel Mosfet/BJT to power a coil on a hydraulic valve cartridge when it reaches a certain analog value. And a weather proof way to place the unit in a calibration mode to map the sensor value to 0 - 100. I'm thinking of a reed switch using a magnet.
Bonus would be to communicate via Bluetooth LE to our app to provide the analog value to enhance its features.
BLE integration would be done with professional help and later 
This would be a proof of concept and will receive a custom PCB if successful.
Some of the questions I have:
Does the WS2811 max out at 12VDC or can they be driven with 13.8 - 14.8 VDC (like automotive voltage)?
If not what is the best way to buck down that low voltage. Efficiency is not critical as I have 25amp voltage source.
What size Mosfet/BJT would I need to not require a heat sink as this will be incased in clear epoxy for weatherproofing? The coil draws 2.5 amps at 12VDC.
What is a common BLE module you have had success with?
Could this be driven with an ATTINY84 or would you recommend a different MCU? I need 1 ADC, 1 Digital input for the calibration button, 1 digital output for Relay/Mosfet Control.
I can do a lot of this with parts I have, but I want to make sure I can keep the footprint small and cost down when/if it goes to production.
Just planning ahead to get some initial costing done.
Also where are some good tutorials on Kicad? I'm learning a decent amount and had experience in High School with board layout but that was a lifetime ago.
