Key fob battery change

Recently the car started to complain that the battery in the keyfob was "low", so it was time to find out how the car and keyfob work together.

Our 2015 Outlander has "keyless" operation, meaning you don't have to insert the key into a lock to operate the car. However if the battery in the keyfob does go completely flat then the car can still be used, via the physical key stored in the keyfob.

Flip the keyfob over onto the side with the Mitsubishi logo.

Slide the releasing mechanism, just above the logo, and slide the key out of the keyfob.

You can use the physical key to unlock the driver's door, then put the key back into the keyfob, and place the keyfob into the slot in the central console, just to the right of the cigarette lighter socket. You can then operate the car as per normal. I'm going to infer that the slot has an RFID reader built into it, and the keyfob has a passive RFID tag, with the code required for the car's immobiliser to allow the car to be used.

Keyless operation is far more convenient, and changing the battery in the keyfob is very quick. At the end of the keyfob where the physical key is located there is a notch in the plastic. Using a screwdriver you can pop the two halves of the keyfob case apart.

The top case of the keyfob, with the buttons, has a CR2032 "coin cell" battery in a holder. The C of CR2032 indicates that the battery is 3V lithium, the R indicates that it is round, 20 is the diameter in millimetres, and 32 indicates a thickness of 3.2mm.

If you can't get hold of a CR2032 you can substitute a BR2032 battery instead. BR2032 are also 3V lithium batteries, but use a different material for the positive electrode. CR2032 are better at delivering the short bursts of current needed for keyfob operation than the BR2032, whereas BR2032 batteries are better for supplying a constant current, as you might find in the real-time clock of a computer. However in a pinch a BR2032 will work in a keyfob.

The old battery can be lifted out.

And a new battery fitted with the positive side,  indicated by a "+", upwards. Try to not touch both the positive and negative sides of the new battery while you're fitting it, as you'll discharge the new battery if you do.

Simply snap the two halves of the case back together, slide the key back into the keyfob, and you're good to go for another few years.

700MHz clearance

Today there were a couple of momentary outages of our fibre broadband internet connection. We're not sure whether the BT Infinity service was at fault, or whether the Draytek Vigor 2860 router just had a senior moment.

Co-incidentally when we turned the TV on later in the day there were none of the terrestrial channels available. Streaming channels and satellite were still working, but nothing from the transmitter in the Gorge.

I checked the BBC's reception service which reported the transmitter was working fine.

But following the link it appears the transmitter had been through some maintenance earlier in the day. Exactly what maintenance is left to the reader's imagination.

After a quick check with an alternative aerial, the only thing left to do was re-tune the BT TV box. Sure enough, the maintenance activity has changed the frequencies that the channel multiplexes were transmitted on.

Delving a little deeper into the need to update the transmitter, it is due to a process called the "700MHz clearance". According to OFCOM: "In November 2014 we decided to make valuable spectrum in the 700MHz band available for mobile data as soon as practicably possible." As terrestrial TV is broadcast between 474MHz and 786MHz, this means that some of the spectrum currently used for TV is being reallocated for mobile data. Note that the Digital Switch Over (DSO) from terrestrial analogue to terrestrial digital TV was only completed in 2012.

So Digital UK, the body behind terrestrial TV in the UK, have come up with a plan to overhaul the multiplexes and frequencies that each transmitter broadcasts, with a view to freeing up the 700MHz band by the end of 2020.

"Following a decision by Ofcom, spectrum in the 700MHz UHF band currently used for digital terrestrial television (DTT) is being reallocated for the development of future mobile services. Some DTT multiplexes will be moving to new broadcast frequencies as a result of this change. Engineering work for the 700MHz Clearance Programme will take place at transmitters across the UK between 2017 - 2020. Freeview viewers (and those with other services that use Freeview channels, such as YouView) will need to retune their TV equipment when changes take place in their area."

Today was the day that the Ironbridge transmitter was scheduled in the clearance programme. Digital UK considers the Ironbridge transmitter to be a part of the Sutton Coldfield transmitter group, rather than The Wrekin group. On page 11 of their January 2018 update for the Central area are the details of the Ironbridge transmitter changes:

RF channel 49 is right on the 700MHz upper limit, and channel 58 finishes at over 770MHz, so all of the previous multiplexes were being transmitted in the band that OFCOM wants to clear. Our current aerial is a Wolsey/Triax HG5 yagi, which is good for receiving channels 21 to 60 (T group), up to the previous 800MHz upper limit on TV transmissions. At the end of the 700MHz clearance in 2020 this aerial is going to be picking up mobile data transmissions as well as terrestrial TV, so will need to changed to one that only picks up channels 21 to 48 (K group).

Additionally we have a Triax TFMV 22W masthead triplexer and amplifier that works up to 862MHz. In theory if the aerial isn't supplying it any signal above 700MHz, then the fact that it can amplify signals up to 862MHz isn't an issue. But no aerial has a perfect frequency response, so it might be worth changing the TFMV for an amplifier with a 700MHz maximum frequency, or put an inline filter between the aerial and the amplifier.

Strangely Digital UK's coverage checker reports that the previous aerial group was K (21 to 48), not CD (48 to 68).

This is incorrect, as a K group aerial is limited to channel 48, and therefore could not pick up the D3&4 multiplex previously being transmitted on channel 58. It also states that the aerial polarisation was, and will be, vertical, whereas the current aerial is definitely horizontal. I think I'll take what it says with a pinch of salt.

Router setup summary

Over time we've enabled and disabled various functionality on our internet router (a DrayTek Vigor 2860ac running firmware 3.8.6_BT), so here's a summary of what's what and why:

WANs

We have BT Infinity 1 FTTC as our primary WAN connection, with a cellular modem on the EE 4G network set up as a failover connection.

The setup for BT Infinity requires little configuration. Leave the DSL mode as Auto and Modem Code as Default. Set the Active Mode to Always On, and check the Load Balance box. For BT Infinity you should enable the VLAN tags in the VDSL2 Service cell in the table. Set the Tag Value to 101, and the Priority to 0.

The setup for the cellular modem is focused on the failover mode. Set Active Model to Failover, uncheck the Load Balance box, and set the failover on WAN Failure. Set the Active When option to Any, and ensure that at least WAN1 is checked.

Internet access via the WAN connections requires BT Infinity to be set up as PPPoE/PPPoA, and the cellular modem to be set up in DHCP mode.

Internet Access configuration for BT Infinity is minimal, just set the Username to bthomehub@btbroadband.com and the MTU to 1492.

Internet access via the cellular modem is also straightforward. We're using the EE network, so just set the APN Name to everywhere.

LAN

We have the router set up with IPv6 disabled, and located at IPv4 address 192.168.1.1. We're only using the 192.168.1.x address space, so the subnet mask is set to 255.255.255.0. The router hosts a DHCP server, but we manually allocate addresses 192.168.1.2 through to 192.168.1.149. The DHCP server leases addresses for 1 day (86400 seconds), and periodically clears the leases for inactive devices. The DNS servers are not specified, so the ones allocated by the active WAN connection are used.

Manually allocated IP addresses are bound to device MAC addresses. We do not use strict binding, i.e. if the device's MAC address isn't in the list then it is not allowed to use the network, as it would be a pain to have to register friends and family's devices every time they visited or changed.

WiFi

WiFi connectivity is provided by the router, as well as two additional access points. A single SSID is used at all three transceivers, on both 2.4GHz and 5GHz bands. Additionally two more SSIDs are used, but hidden, one each on each band, for devices that struggle with the single common SSID.

To minimise the possibility of interference the router is on Channel 1, whilst the two other access points are on Channel 11 (to enable the WDS bridge), and all access points are set up in Mixed Mode with 20MHz channels.

Each SSID is secured using a Pre-Shared Key (PSK) exchanged with WPA2 only.

The extension of WPA2 called WiFi Protected Setup (WPS) is disabled due to known vulnerabilities.

In order to promote the use of the 5GHz band, to maximise the bandwidth available for the WDS wireless link from the house to the workshop, Band Steering is enabled. When the access points detect a device trying to simultaneously connect to the common SSID on both 2.4GHz and 5GHz bands, the device will be deliberately stopped from joining 2.4GHz for 15 seconds. By which time the device should have connected to the 5GHz band.

The setup for the 5GHz band is similar to the 2.4GHz band.

As the 20MHz channels in the 5GHZ band do not overlap with each other, the router uses Channel 36, whilst the other access points use Channels 40 and 44. These are in the A-Lower (5150-5250GHz) band, so Dynamic Frequency Selection (DFS) and Transmission Power Control (TPC) do not apply.

Security on the 5GHz band is setup the same as the 2.4GHz band, and WPS is also disabled on the 5GHz band.

Hardware Acceleration

We do not use hardware acceleration, so that all traffic passes through the Data Flow Monitor and Traffic Graphs.

UPnP

Universal Plug and Play (UPnP) is disabled, as it is insecure by design and enables devices on the LAN to open up ports in the Firewall in order to communicate with external servers.

IGMP

The BT TV YouView PVR uses a combination of the terrestrial aerial to receive FreeView channels and IPTV to stream the other channels via Infinity. This means the PVR needs to be able to join IP Multicast groups, so the IGMP proxy must be enabled. Additionally to avoid swamping the WiFi with multicast packets IGMP Snooping and IGMP Fast Leave should be enabled.

Dynamic DNS

The router is dynamically assigned an IP address for the WAN interface, so in order to enable VPN access to the LAN via the router there are 2 dynamic DNS entries maintained. Every 1 day (1440 minutes) the router reconfirms the WAN IP address with the dynamic DNS service.

These are provided by the free service No-IP.com, and are set up with a Domain Name, Login and Password provided by No-IP.com.

VPN

The router runs a VPN server so that we can connect remotely to the home network via smartphone or laptop in order to access the security cameras, or geo-locked services such as the BBC iPlayer when travelling abroad. We use the Draytek Smart VPN Client, which has clients for the two OS that we use: Android and Windows.

First we will enable VPN via an SSL Tunnel.

Then add a Remote Access user account, with access via the SSL Tunnel enabled, and a 5 minute timeout.

If you create more than one Remote Access user account, you can individually activate and deactivate them.

When the user connects remotely this is indicated with green text, rather than red text.

More detailed stats on the connection are also available.

On a Windows PC you need to install the Smart VPN Client, and then Insert a new Profile for the router that uses the SSL Tunnel and supplies the same credentials as the Remote Access user account.

Once connected Windows sees a new virtual network connection called DraySSLTunnel.

On an Android phone the Smart VPN Client is available through the Google Play App Store, and once installed is available either via the app matrix or via the VPN Settings.

As per the Windows setup, first create a Profile using the + symbol at the bottom of the screen.

 

Then pressing on the Profile connects and disconnects the phone to the router via the SSL Tunnel.

Power switching - wall socket v. smart plug

It is that time of year when we bring trees indoors, which then sprout lights and hide wall sockets out of reach. Not only does it get tricky to get to the socket to turn things on and off, but it also intrigues me to know how much extra power the festive decorations are using.

So I had a quick look around for the options for smart power switching. Ideally I'd like to replace the wall sockets themselves with smart versions. There are a couple of options here, Den (which is due to launch in early 2018) and Energenie. The downside to these are the lack of power monitoring, and unavailability in the case of Den.

There are far more options available for smart plugs, even with power monitoring built in. There's the TP-Link Wi-Fi Smart Plug with Energy Monitoring, the Belkin WeMo Insight Switch, the Energenie Smart Plug+, the Elgato Eve Energy, the Efergy Ego Smart WiFi Socket, to name a few. Some connect directly to your WiFi, some connect to a home automation hub, and almost all work with Amazon's Alexa and Google's Assistant. The exception is the Elgato Eve Energy, which is Bluetooth connected and only works with Apple/Siri/iOS devices. There's not that much differentiation between each product, except on price where the TP-Link is the cheapest at £29.99 and the Belkin the most expensive at £49.99. I bought the TP-Link HS110,

which has a prodigious and unnecessary amount of packaging. It certainly doesn't need a plastic insert inside a cardboard inner box, inside a cardboard outer box.

Setting it up is pretty easy, just plug it in and let it initialise itself (flashing orange light). As with all smart home systems there's a cloud backend to keep tabs on your devices and enable remote control. You need to download the Kasa for Mobile app from your respective app store, which gives you the option to create a new account with the TP-Link Cloud.

Right now the web interface to TP-Link Cloud is only focused on their video cameras, so you can log in using the account credentials you supplied to Kasa, but the web interface just reports that "no camera exists in this account". Maybe in the future the web interface will encompass all of TP-Link's smart devices.

Back in the Kasa app you'll need to add a new device. To do this the app disconnects your phone from your WiFi, and scans for the HS110 which has set up it's own WiFi hot spot. Once detected you can set up the WiFi the HS110 ought to connect to, and configure a friendly name and icon for it. When all is done the HS110 displays a solid green light, which is mimicked in the Kasa app.

I am quite impressed with the lack of latency between switching on the app and the HS110 responding, it is as immediate as you really need. And if you can actually reach the HS110, you can turn it on and off via a button on the front of it.

Enabling voice control with Amazon's Alex was pretty straight forward. First use the Alexa app to enable the TP-Link Kasa skill, then go into the Smart Home section and Add Device. Alexa and Kasa integrate at their respective backend clouds, so the Alexa app will take you to the TP-Link Cloud to authorise that integration. Then you can simply say "Alexa, turn on Christmas Tree".

For Google's Assistant the process is the same, but the order of the steps is slightly different. Instead of enabling a skill then adding a device, in the Google Home app you go to Home Control and add a device, then scroll down the list of integrations under Add New to find TP-Link Kasa. The Google Home app will again take you to the TP-Link Cloud to authorise the integration, before finally getting you to allocate the HS110 to a Room.

With both Alexa and Assistant the delay between the spoken command and the tree lights switching on and off is pretty small. Not quite as immediate as using the Kasa app, but certainly quicker than getting up off the sofa, crossing the room, fighting through the tree, and switching the lights off at the plug.