IoT Software Notes

I’m trying to get my head around all the IoT “hub” software options. I’m focusing on software that runs locally, rather than proprietary cloud services like IFTTT.

List o’ IoT Softwares

Open Source

Proprietary

  • Hubitat (link) Proprietary gateway that works without “the cloud.” Provides API for apps and drivers and SmartThings compatable scripting language. Ships with support for with ZigBee, ZWave and IP based devices.
  • Phillips Hue Bridge
  • Samsung SmartThings Hub (link). Closed source running on proprietary hardware HUB, but extensible and works with both Samsung and 3rd Party IoT hardware over Zigbee, WiFi and Z-Waver

Details

Home Assistant

“Open source home automation that puts local control and privacy first. Powered by a worldwide community of tinkerers and DIY enthusiasts.”

Has native (python) HomekKit support

Homebridge

Homebridge is opensource software built on Node.js.

It describes itself as “HomeKit support for the impatient”

It provides a path to Apple HomeKit support for a variety of 3rd party ecosystems, like Samsung SmartThings by emulating the HomeKit API.

People have provided plug-ins and guides to enable all sorts of useful integrations.

asdf

Mozilla Webthings Gateway

openHAB

Other Notes

Solar Panel Notes

I’ve been tinkering with a small, semi-potable solar setup and have an eye to upgrading it. These are my notes. My facts my be incorrect, they are certainly incomplete.

My system is currently configured as:

  • 18W, 18v flexible Sunpower panel.
  • CN3791 MPPT charge controller
  • LiIon battery pack(s) made from 1S20P Samsung 28A 18650 cells. Configured as two packs of 1S6P and one pack of 1S8P, each with a cheap protection board. Estimated capacity is ~150Wh
  • ~15W 6v folding, portable panel, made from Sunpower cells. I’ve added a bypass for the buck converter that supplies regulated 5V USB so I can use it with MPPT controllers.
  • 21W 6V folding, portable panel, made from Sunpower cells. I’ve added a XT30 connection so I can swap in different loads, including the original 5v USB buck regulator, a different buck regulator, or an MPPT controller.
  • These folding panels are hooked up parallel, they are connected to another CN3791 MPPT charger.
  • Both chargers are connected in parallel to the battery bank. This could have some weird effects, particularly as the pack reaches 4.2v and goes into constant voltage mode.

The panels are not optimally deployed. They are lying flat, and due to trees, etc, only get unobstructed sun for ~4-6 hours a day. In this arrangement, peak power for the 18W panel has been about 10-12W.

The 6v panels are even more suboptimally deployed due to sitting on the floor of a window platform for cats, which means they are obscured at times by the frame and even the 18W panel which rests above them.

I also have a laminated ~6W 5V Sunpower panel that is currently unused. It originally had a buck regulator to power USB devices, but I removed it and replaced it with a quick release terminal so I can use it directly with a battery charger.

I’d like to move up to 100-200W of panel capacity before a new wave of Trump’s dumbass tarifs hit. Options in consideration:

  • Rigid mono or polycrystalline panels.
    • Polycrystalline is currently slightly cheaper per nameplate wattage, but maybe not enough to be compelling. Currently <$1/W.
    • Pro: Cheapest option. Con: Since I’m not making a permanent installation, the fact their weight and fragility of the glass is a concern.
  • Flexible panels. Lots of options, most of them dubious.
    • The cheapest flexible panels are available at a ~20-50% premium over rigid panels.
      • Use PET encapsulation on the sun-facing side, which isn’t suitable for constant environmental exposure.
      • Use cell constructions that don’t hold up to flexing and don’t deal well with microcracks that develop in the silicon wafer due to flexing.
      • Use panel interconnects that won’t hold up to flexing.
    • Quality flexible panels are 2-3x as expensive as cheap rigid panels.
      • Use EFTE top layer for long life and durability.
      • Use primarily Sunpower, but occasionally Day4 or Merlin cells which are well suited for the challenges of flexible substrates.
      • Use rugged, flexible interconnects.
    • Folding flexible panels.
      • One, common variety uses ~6v, 7W subpanels connected in parallel to power a 5V USB buck regulator. The subpanels are made from twelve Sunpower offcuts in series. These are typically encapsulated in PET and sewn into ballistic nylon covers with cardboard for added stiffness. Newer designs use EFTE and may forgo the fabric construction a fully laminated construction and a panel thickness of 2-3 millimeters..
      • $1W at the low end, >$2W for branded products like Anker or RavPower.

Background Information

  • Panel Basics
    • Solar panels are constructed from multiple photovoltaic (PV) solar cells in series.
    • A typical PV solar cell has an optimal voltage of about 0.5-0.6v, which is determined by the bandgap of the doped silicon junction.
    • The number of cells assembled in series determines the panel voltage.
    • Panel voltages are generally matched to their intended application.
      • Six cells in series (6S) are well suited for 3V electronics of the sort powered by two Alkaline cells in series or a single lithium metal cell (like the ubiquitous CR2032 button cell.
      • Ten (5V) to twelve (6V) PV solar cells in series are typically used to charge/power 5V USB devices by way of a buck-converter voltage regulator. These configurations are also well suited to charging Lithium Ion batteries, which are used in smartphones and most other battery-powered devices that can be charged from USB.
      • Panels made from 32-36 cells in series are common. They have an optimal voltage of 18V, but are often labeled as 12v because they are used to charge 12v lead acid batteries without a regulated charging circuit. The are also used with LiIon batteries in conjunction with a suitable charging controller. ~100W, 18V panels are often connected in series for higher-voltage and higher powered systems, including AC systems
      • 150-300W panels with 50-72 PV cells in series are also used in larger installations.
    • Panel Construction
      • Panels are assemblies of multiple, electrically interconnected, solar cells. They protect the component PV cells from the elements, and provide support when deploying and mounting the cells
      • Rigid
        • Framed Laminate panels sandwich the cells and their interconnects between glass and a sturdy backing material. The laminated panel is then held in an aluminum frame to enhance rigidity, provide protection, support and points of attachment for mounting the panel.
        • Cast panels are typically under a few watts of power. They seal the cell in protective epoxy or another cast resin.
      • Flexible
      • Laminated

Digoo IP Camera Teardown and Links

I was just looking at unfinished posts and noticed that I’d taken, but not published, a bunch of notes I’d made earlier this year in hopes of hacking better firmware onto the Digoo BB-M2 WiFi PTZ Security Camera.I gave up on the quest, but here are my notes, with minimal editing.

Someone mentioned that the Chinese language page for Netcam360 has a link to the IPC-SDK. When I downloaded it and looked inside, I saw client-side code, but there was also a self-extracting archive called “HSmartLink Win32 SDK” and I remembered the PCB marking started with “HSL.” Searching for HSmartLink brings up hsmartlink.com, which, among other things, has IP webcams! The i9812 looks like a good match for my camera!

Unfortunately, no sign of any firmware updates. I checked the .cn version of the site too. It doesn’t seem as up to date on products (i9812 isn’t listed), and while there is more info in support section, it is still quite sparse. Page that looks like it is intended to link to downloads hasn’t been updated since 2015

Company is “Shenzhen Hsmartlink Technology Co. Ltd”

FCC Database listing for company

So what is the relationship to NetCam360 (check whois & IP ) and they mysterious APKLink?

Nmap Pobe

Starting Nmap 7.40 ( https://nmap.org ) at 2017-02-06 18:38 PST
Nmap scan report for 10.31.1.124
Host is up (0.0043s latency).
Not shown: 998 closed ports
PORT STATE SERVICE
23/tcp open telnet
81/tcp open hosts2-ns
MAC Address: E0:B9:4D:8F:61:6C (Shenzhen Bilian Electronicltd)

Nmap done: 1 IP address (1 host up) scanned in 0.49 seconds

Teardown Inventory

Photos

Ingenic

Module with Mediatek MT7601UN

Unknown

  • 15UDN8WY, ULN2803AG 18Pin in 2-row SMD
  • Darlington Transistor Array: http://www.ti.com/lit/ds/symlink/uln2803a.pdf
  • Probably used for driving PT motors

Atmel 542

  • 24C02N, SU27D
  • AT24C02
  • Two-wire serial EEPROM (2K)

Vertical PCB

  • SF1810-002, www.sufeitech.com. PCB antenna?

oosilicon or dosilicon?

Other