Application of Bluetooth Low Energy in Classic Cars Rogier van der Hee

Rogier van der Hee : Zoidberg Solutions (independent developer - ZZP) PlantScout app (iOS / Android) for variety assessment for orchid growers: Invoice Management for Blue 10: ATC simulation tests for candidate selection purposes for EUROCONTROL: Ignition systems for classic cars: 2

The project: classic car ignition systems How does an engine work: Suck -> Squeeze -> Bang -> Blow! Modern cars ignition is done purely electronically, classic car it is mechanical on the crankshaft 3

What does an ignition system do? Timing of the spark for optimal combustion, right at the moment the cylinder is at the top dead center. Based on piston position (advance) and power demand (vacuum) 4

Why electronic ignition in your classic car? Why electronic? No more maintenance Better starting Better torque in lower RPM Why programmable? Almost endless combinations possible: different curve per engine, distributor and fuel (petrol, ethanol, LPG) Fabrication is unified: 1 embedded software program Best possible setup for your specific engine: tuners and export hobbyists (racing) Because we can 5

Atmel ATMega16 8Mhz -40 – 120 Celsius 16kb Flash Windows XP / 7 / 8.Net 2.0 app RPM Battery Temperature Manifold pressure Ignition advance Today Serial over USB Rx Tx 6

Atmel ATMega 8Mhz -40 – 120 Celsius 16kb Flash IPhone 5S Dual core 1.3 GHz ARM v8 16/32/64 Gb 1 GB RAM DDR3 ? RPM Battery Temperature Manifold pressure Ignition advance The challenge Rx Tx 7

Wireless hardware options Classic Bluetooth 1.1/2.0/3.0 ( ) Slow, long latency, requires MFI program for Apple Smart Ready: Dual mode device with 4.0 and classic, Smart is 4.0 only ZigBee, mostly home automation No frequency hopping, not present in devices. No hardware support in phones. Wi-Fi Point to point difficult (Direct), software hard, optimized for large data transfer ANT (+), mostly health and fitness Proprietary, + since 2011 requires certification. Native Android, no iOS NFC Range limited to 5 cm, targeted for payments. Android, no iOS 8

Why Bluetooth 4 Low Energy? Hype “Internet of Things”: enables low cost, low power sensor communication between endless combination of devices, wearables, you name it! Proximity and out of range detection (geofencing) Fast connections (10 msec) and low data latency (3-6 msec): very responsive apps Adaptive Frequency Hopping (AFH), resilient to interference Broadcast support (iBeacons) Connectionless always off technology Low power consumption: ~30μA average consumption with 1 second data interval, equivalent to 330 days on a single coin cell Range up to 280 meters (in practice about meters) No more MFI program for Apple 9

Real life range sample Direct line of sight 30m Faraday was right! Plastic casing in prototype Still connected! Static timing LED Bluetooth Status LED Ignition behind fan under hood 10

Hardware implementation System-on-Chip: Bluetooth needs external controller with embedded software to run Option 1: buy separate chip: TI CC2540/CC2541, Nordic nRF8001 Complete control High startup costs (FCC, dev kits etc etc) Option 2: buy integrated solution: BlueGiga, BlueRadios, CSR, Nordic No FCC approval Avoid high dev kit license Ready to go Drawback: “vendor” libraries CC2540 under RF Shield Antenna EEPROM Crystal / Transistor 11

Bluetooth Low Energy Architecture GAP ATT L2CAP GATT GAP Role Profiles (Master / Slave) GATT Profiles User Application Host Controller Interface (HCI) SMP Host Controller Link Layer (LL) Physical Layer (PHY) Application 12

Generic Acces Profile (GAP) Ensures basic connection handling: discovery of what type of Bluetooth profile a device supports Common for Bluetooth 1/2/3/4, basis for all profiles Handles advertising and roles Handles security (SMP): Bonds or pairing between devices Access and address security 13

Generic Access Profile (GAP) : Roles Transmit advertisement only (iBeacons) Broadcaster (Advertiser) Only receives advertisements Observer (Scanner) 1 connection to a master Peripheral (Slave) Supports multiple connections Initiates connections to devices in peripheral role Central (Master) Central Periph eral Broad- caster Obser- ver 14

GATT Profile Bluetooth SIG defines standard Profiles for interoperability: HID, Health, Hear Rate, Proximity, Cycling Power, Find Me, etc Profile Service Characteristic C# sort of comparison: Profile = Model Service = Class Characteristic = Property Descriptor = Property Attribute 15

GATT Characteristic Value types: Broadcast Read Write Write without response Notify Indicate (needs reply) Descriptors describe: Presentation format Valid Range User description … See Bluetooth.org for complete specification Characteristic Value Descriptor 16

Overh ead Protocol Data Unit (PDU) Overhead Preamble Advertisement Packet layout Acces Address Adv Header Payload Length Advertiser Address Payload (31 bytes) CRC 17

Support per platform Available Since 6.0 (IPhone 4S / IPad 3 and newer Most mature API and software Pairing almost workable Since 7.1 notification triggers for closed apps Very buggy in 4.3 Better in 4.4 but still “adventurous” Open source iBeacon library Background Service way to start app Windows 8.1 too barebones: Store only, missing API’s Phone 8.1 big improvement, also includes background Triggers Preview not working on Nokia (which did initiate Bluetooth Low Energy research in 2001! sigh) 18

Show me the money … code! Example for reading the Battery Level characteristic iOS Android Windows 8.1 (or how far I got..) Windows Phone 8.1 (theory only..) 19

Security Security modes “Just Works”, no pairing needed to connect (doesn’t work with Windows 8) Simple Pairing (Authorization only, no PIN) Secure Authenticated Pairing with MITM protection (PIN) Triggered by setting certain permissions on characteristics Personal experience so far: authenticated pairing is difficult to implement to cover all use cases for devices without a display. Also there are bugs in both iOS and Android which makes the experience cumbersome 20

iBeacons Hype in the advertisement market, new way to personalize shop experiences Broadcast devices, not connectable Special layout of Advertisement Packet Company identifier code set to 0x004C -> Apple iBeacon proximity uuid in manufacturer data Major / minor Id (for grouping beacons: home->living, attic, basement) Measured Power (RSSI in dB at 1m, translated to immediate, near, far) 21

Conclusions / Lessons learned BLE is fast and fluid from end user point of view Hardware integration is always a big pain Writing polished apps takes an incredible amount of time ;-) 22