State of the (IoT) Union 2020

It’s been a little while since I first started building IoT gizmos for my house and I’ve continued to improve and add to them so I thought it was a good time for an update on how some of the projects have fared, what’s new and what I’m thinking of for the next year.

2020 has been one hell of a year – My team and I have been lucky enough to be able to continue working from home and even managed to ship some products along the way. However, spending so much more time at home has caused me to spend more time thinking about my environment. Small irritations are magnified into daily hassles and new issues present themselves, giving opportunities to optimise my work from home life with more projects.

Smart Heating

Back in February I wrote about how I had modified my central heating be smart without damaging the property or replacing any of the components. This project was my first adventure into 3D printing and the ESP8266.

A year on, the system is still installed and running my heating on a daily basis. I am very pleased with how well it’s worked with only a few changes:

  • Missed MQTT messages – In the first few weeks, there were a few occasions where the heating would not turn on or off when instructed. When I investigated, it seemed that MQTT messages would not always be sent to the device when published. To work around this, I added code that forcibly checked the state every 10 mins and would perform the missed action if needed.
  • Restore previous state – In the original version of the project, the device would take the latest value published to the MQTT feed as the source of truth. However, this was problematic as if a new message was published while the device was not available for some reason, it would run out of sync – meaning that the heating would turn off then instructed to turn on and vice versa. To fix this I used the ESP8266’s SPIFFs storage to store the current state of the heating toggle and restore it after device restart.
  • Timing – The timing to switch the heating on and off is no longer powered by IFTTT, instead it is now powered by automations in Home Assistant, which allows me to create more complex programs.

Digital TV Recorder

In May I wrote about how I used Kodi and Tvheadend to build a TV recorder. This is still running and recording TV shows. I’m very happy that I can stream its recording through my home and watch them in the kitchen while cooking. I’m also really happy with the massive saving I’ve made by cancelling my paid TV contract. It’s not been without it hiccups though:

  • Live Pause – For some reason pausing live TV does not work as expected. I can pause and restart the broadcast , but a few seconds after restarting, playback fails and cannot be resumed. I don’t really watch much live TV, so I’ve not yet been sufficiently annoyed to investigate this.
  • Start-up Issues – On bout 50% of start-ups, Tvheadend fails to start and cannot be used. To resolve this, I have to manually stop and restart the service. I haven’t yet looked into what is causing the issue, but its high on my list.

Living Room eInk Display

The living room info display continues to function, and I use it a lot to know if it will rain when going out. However, with Apple’s acquisition of Dark Sky and subsequent deprecation of the API, I will need to update it at some point in 2021 to use some other data source. If you’ve any good suggestions of where to get similar information for, I’d love to hear them in the comments or on Twitter.

Air Quality Monitoring

I’d already been monitoring my air quality with my Arduino & Raspberry Pi for a while before I Wrote about it. Unfortunately, while building it a new case, I accidentally damaged the Raspberry Pi and OLED screen. As I always wanted to improve it, I descried to rebuild a whole new version using an ESP8266, utilising deep sleep mode, to create a device that is significantly smaller and more power efficient.

I was pleased with how neat this new version was when in a nice 3D printed box. I was very happy with its crazy low power consumption between air quality samples every five minutes. However, it has an issue – the temperature & humanity sensor is too close to the gas sensor, meaning that it suffers crazy self-heating to as much as 10c, which made its data very unreliable.

It still works as a volatile organic compound sensor, but I will need to re-think the board layout to get reliable data from the temperature and humidity again.

Home Assistant

Over the year, I added yet another Raspberry Pi to my home, this time running Home Assistant. I’ve been really pleased with the power of automation I’ve set up with this. I’ve used it to automatically start the Roomba if I leave the house between certain times, automate the outside lighting and provide more powerful timing to the smart heating project.

I also added a Conbee Raspbee II to the Raspberry Pi, to allow it to communicate with Zigbee devices. I now have a Xiaomi temperature sensor in every room and a set of Ikea Trådfri lights in the bathroom. Eccentric as this may seem, its allowed for some really nice and inexpensive luxuries – such as turning the on heated blanket in the bed before bedtime if it is cold in the bedroom or adding mood lighting in the bathroom when you want to relax in the bath.

2021

I’m pretty pleased with some of the things I did over the last year, but I’m looking forward to building some even more cool things in 2021 and sharing them with you.

With working form home continuing to be necessary for the time being, I want to focus on improving my environment to keep it fresh, interesting and comfy as well as dealing some of the pain points while working. I’m going to be adding a lot more automations with Home Assistant as well as building out my smart lights through a const effective use of Hue and Ikea lights.

If you have any cools suggestions or ideas that you think I might be interested in, drop me a comment below or on Twitter.

Hope you have a great 2021! (Or at least a better one than 2020)

How I Made My Heating Smart Without Damaging Or Replacing Anything

I’ve previously mentioned that I wanted to upgrade my heating system so I could program it with more complex timings or control it form my phone. But there’s a catch: The house is rented, so the whole system must do no damage, be made only of removable parts and be installed without modifying any of the existing infrastructure.

In this post, I’ll talk about how I managed it, how it works and what the current state of the project is.

Background

My electric heating is controlled by a Timeguard RTS113 mechanical timer located awkwardly in a kitchen cupboard; it consists of a large outer ring that rotates once every 24 hours. On this ring, you push in red (on) or blue (off) plastic pegs (called tappets in the user manual) at the time you want the heating to turn on or off. As the peg passes a control spindle (representing the current time in the bottom right) it pushes it around approximately one eighth of a turn. Each eighth of a turn of the control spindle, toggles the heating on or off.

A second inner ring allows you to suppress the morning or afternoon schedule for a given day in the week. For example, you can have the heating come on at 6:00am and 7:00pm every day, except on Saturdays where it does not come on at 6:00am because the morning schedule is suppressed.

This works reasonably well, but it’s not very flexible – you pretty much a to live your life on the same schedule every day – if you deviate from it the heating is either wasting power while you’re out, or you’re freezing and have to reach into the cupboard to press the override button.

I’d love to have a smart thermostat such as Nest or Hive but they don’t support my electric heating and as this is a rental house, I’m not able to modify anything to support them.

What I Wanted To Do

The control spindle that is rotated by the pegs has a small slot on the top that can be turned manually using a screw driver to toggle the heating on an off. I can remove all of the pegs and use a stepper motor to very gently turn the spindle each time I want to change the heating state. I could then connect this to a controller that receives instructions from the internet, and write whatever software I wanted to run the schedule.

The Motor

Continue reading

Using the Monoprice Voxel (FlashForge Adventure 3) With Ultimaker Cura

Recently I bought a Monoprice Voxel (a rebranded FlashForge Adventurer 3) 3D printer, and I’ve spent the last couple of weeks getting to grips with it. I’m very impressed – it works well and I’ve had a lot of fun building parts of my projects.

One interesting this about the printer is that it comes with its own slicing software called FlashPrint. This seems to work quite well, slicing all the models I threw at it and sending them to the printer. However, I was curious if it was possible to use the printer with the Ultimaker Cura slicer, which has some more advanced features and is supported more widely by the community.

I did a load of research and found some interesting topics on reddit and Ultimaker forum, I also examined the .gx files produced by FlashPrint and thoes sent to the printer by PolarCloud. I’ve gathered all this together into a this guide for using Cura, but it stands on the shoulders of a whole bunch of other people in the community, so thanks to those people you really helped me figure all this out.

Update (January 2011): A YouTube user confirmed that these steps also work for the FlashForge Adventurer 3 Lite.

Disclaimer

Every model I have printed in this way has worked well and I am very pleased. However, follow this guide at your own risk – If something bad happens to your printer, on your own head be it.

Observations

FlashPrint and the printer appear to use a custom file format for printing – .gx. This is identical to the .g file used by other printers but with some additional metadata at the top. I suspect this is the image of the model that’s shown while printing, as well as the print time estimation.

The printer is perfectly happy to print .gcode files, provided the file extension is changed to .g first. While printing a .g file the time estimation on the printer screen does not count down the remaining time, it counts up the elapsed time. Also instead of a small image of the model being shown, a generic icon is displayed.

Getting Cura

Firstly, you need to install the latest version of Cura from the Ulimaker website.

Continue reading

New Project: Zero Damage Smart Heating in a Rental House

This is the first post in a series documenting my attempt to build a smart heating system for a rental house. Further posts will follow as I work on it.

I have electric heating in my house, powered by a central timer from the past. The timer is a masterpiece of engineering, but is incredibly crude by modern standards. I’d love a connected system such as Nest or Hive but these systems only support low voltage trigger systems found with most gas systems, not the high voltage switching I have.

So I want to build my own, It’ll be fun, educational and greatly improve my quality of life in the winter. There’s just one thing though: I don’t own the house, so whatever I do must be easily reverted / removed / undone. Also, I’m a software not an electrician so, in the name of safety, I am not re-wiring anything or changing how it currently works.

The Timer

The timer is a Timeguard RTS113, it supports switching the heating on or off once every 30 mins by inserting a red (on) or blue (off) tappet at the appropriate time. On an inner ring it supports suppressing this schedule for the morning or afternoon for any day in the week. For example, you can have the heating some on at 6:00am, and 7:00pm every day, except on Saturdays where it does not come on at 6am.

The tappets are attached to a rotating dial, which rotates once per 24 hours. Each tappet has a lug, that as it passes a control spindle, pushes it around an 8th of a turn. As the control spindle is rotated it toggles the heating on or off.

The Plan

The control spindle has a plastic screw slot on the top to help you see its current state when programming the timer. So, in theory, I can remove all of the tappets and turn the control spindle manually (and very gently) using a stepper motor each time I want to turn it on or off.

Proof of Concept

I picked up a suitable looking stepper motor and motor controller from The Pi Hut, and hot glued a washer to the end. By holding this in place I was able to turn the heating on an off by rotating the motor with an Arduino. Now to figure our a more permanent arrangement…

Next Steps

I’ve already used Tinkercad and made a driver head to fit over the motor shaft and engage with the timer’s control spindle (replacing the hot glue blob from the proof of concept), I’ll 3D print this and see how it goes. Then I need to design some kind of support to hold the motor in the correct place so I can let go of it.

The above gif was made using Paint 3D ❤️