Home Automation – Fun With The House Part 4

So I now had a jumbo Raspberry Pi, I still had to re-install the software and restore the programming flows and data to the new SSD.

It took a few YouTube videos to do this, it involves some pretty Geeky commands being sent to the Pi in order to get it to start up without an SD card and to use the SSD instead. It all went well though and a couple of hours later the Pi was running ok. However, none of my controls worked anymore, it appeared it was all happy, no errors in the logs, but nothing did anything – light switches did nothing and the software could not turn on a light etc.

This was panic time – carry on or put it back to SD card?? I sought a lot of help on this one, spent about 5 hours sweating over a hot laptop and generally burning up the internet.

Now, in order to get the Pi to talk to lightbulbs and other smart devices, you need to fit something called a “ZigBee dongle” (or Z-Wave if using that) – a small device that plugs into a USB port on the Pi and contains a small radio transmitter / receiver that sends commands to the devices and receives messages back from same devices about their status etc. The one i chose was the “ConBee II” which seemed to be well recommended.

A few more hours were spent, much coffee was consumed and a repeat topic started coming up on searches – USB3 and WiFi – It seems there is a known issue with the new USB3 high-speed connections and things like cordless mice, keyboards and of course ZigBee dongles! Some nice person sent me a link to a published white-paper from Intel that explained it all.

It all boiled down to the fact that USB3 seems to run at the same frequency as the smart devices do; 2.4 GHz which is also the same as general WiFi. When in use the USB3 device or its connectors can emit interference strong enough to cripple some devices – the ZigBee dongle is one of these and it is usually plugged in to the same computer as the offending USB3 devices!

Why had the issue sprung up now when the USB3 ports were there before? Simply because they were not being used but the SDD drive uses USB3 to connect to the Pi main board so the USB3 bus was now extremely busy and emitting a whole mess of interference.

Clearly a fix was needed, the answer popped up with some more searching – take the ZigBee dongle out of the USB port on the Pi and fit it to a USB extension cable, then fit the cable into a slower USB2 port – the Pi has two USB3 and two USB2 ports.

This fixed the problem instantly and with 15 minutes, all the bulbs and devices had reconnected and we were in business again. It’s been running for a couple of days now and seems stable, the SSD is also much faster than the SD card as well. Now that it’s fitted, the SSD mounting board has a little blue LED on it that flashes when the drive is used – this LED highlights why the SD cards suffer, it really gets a lot of use!

Continued…

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