Date post: | 07-Aug-2015 |
Category: |
Devices & Hardware |
Upload: | farmckon |
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IOT BEST PRACTICES:PICKING A PROTOCOL
(for embedded development that sucks less)
@farmckon @BuLogics
PICKING THE RIGHT WIRELESS PROTOCOL IS KEYIt defines your ecosystem, your sales channel, and pretty much everything else.
Key factors determined by your wireless choice
• Device price • Sales channels, partners, integration
options• Physical Range, power lifetime (battery,
etc) • Debugging complexity• Debug and Development time
Most Common Wireless Protocols• WiFi• Bluetooth • Bluetooth LE • Z-Wave • Zigbee• Others (Thread, Instion, etc)
Key Metrics (in human terms)• Network Type• Mesh, Star, Point-to-Point, Tree, …
• Range:• A table, a room, a house, a block, several blocks
• Data Rate• A text, a photo, a song, choppy video, a movie
• Developer Tool Quality:• Anyone, Hobbyist, Pro, Grey-Beard
• Batterie Lifetime• an Hour, a few hours, a few days, 2 years, N/A
WiFi Overview• Stats:• Network: Star; Range: house• Data-rate: up to movie; Tools: anyone • Batteries: a few days*
• Well loved; 802.11 family of technologies• Wavelan (1991ish) -> 802.11b … profit? • Ubiquitous standard for wireless internet communication.• Well built and tools abound.
WiFi Weaknesses• Very energy intensive. Slow ramp-up time(~1 sec)
• Pairing securely or picking a network is a pain.
• Complexity of a whole networking stack.
• Point-to-point style network is a limit
• Bad for: Simple, battery-powered, cheap devices; fast-response behavior
WiFi Strengths• Great data through-put.
• Excellent standard; evolving and expanding.
• Ubiquitous in many homes & businesses.
• Good for: Wall-wart devices, streaming data, “cloud” connected devices or projects
Bluetooth Overview• Stats:• Network: Point-to-Point; Range: desk• Data-rate: song; Tools: pro • Batteries: a few years
• Since 1994. Invented by Ericsson.• “Replace USB cable” style communication• Lots of devices, good adoption in the phone world.• Bluetooth up to v3 is “Basic Bluetooth”.
Bluetooth Weaknesses• Device-to-host model is limiting.
• Phone-centric; few gateways or home-install devices.
• Bad for: Distance transmission, multiple devices, complex networks, large amounts of data
Bluetooth Strengths
• Device-to-host model is simple.
• Low power. Lots of devices to pair to.
• Easy to test. Lots of tools and developer kit.
• Good for: Audio streaming, data sensors, pico-networks, peripherals
Bluetooth LE Overview• Specs:• Network: Star; Range: desk+• Data-rate: photos; Tools: hobbyist, • Batteries: A few years
• Subsection of “Bluetooth 4” standard.• Was a separate standard “Wibre”.• Just reaching decent adoption with the latest phones.
Bluetooth LE Weaknesses• Not compatible with Bluetooth 3.0 or older.
• Potential problems in joining (or discovery).
• New standard. Still growing in adoption.
• No good “gateway” device available. (Yet.)
• Bad for: Streaming lots of data, long range, mesh scenarios
Bluetooth LE Strengths• Low power.
• Extensive (and growing) install base.
• Lots of familiarity in the mobile/app field.
• Good for: Rechargeable battery-powered sensors; data collection; simple, end-user devices
Z-Wave Overview• Stats:• Network: mesh; Range: house• Data-rate: text; Tools: super-pro*• Batteries: a few years
• Sigma Designs and the Z-Wave Alliance.• Well specified (private) protocol stack.
Z-Wave Weaknesses• Captive eco-system; no open standard.
• Developer kit is rough around the edges.
• Complexity for backwards compatibility.
• Bad for: Streaming video, wifi, long-range, pairing to phones
Z-Wave Strengths• Mesh network = More coverage
• 1,000 certified devices.
• Clear “Pass/Retry/Fail” certification.
• Good integration partners.
• Good for: Security systems, house control, simple sensor reports, scene/settings changes
Zigbee Overview• Stats:• Network: mesh(ish); Range: house • Data-rate: text; Tools: hobbyist • Batteries: a few years
• IEEE 802.15 based with “flavors”.• A mesh network system, but often used point-to-point.• Well liked by DIY and hobbyists.
Zigbee Weaknesses• Lots of “flavors” that can pass, but can’t parse other flavor messages.
• Not many controllers, integrators or gateways on the market.
• Bad for: Streaming video, wifi, long-range, pairing to phones
Zigbee Strengths
• Easy to get started with. Decent starter kit.
• Public standards; multiple vendors; no single gatekeepers, but there are per-flavor gatekeepers.
• Good for: Home automation, smart lighting, wireless sensor networks , DIY projects, remote control