Reduce, Reuse, Recycle - an environmental approach to your IoT projects
With new consumer electronics emerging on the market almost every minute and sometimes using the same technology, but packaged and marketed differently, it is an unfortunate by-product that millions of tons of electronic waste is produced worldwide, each year.
Everybody enjoys new technology but how many of us act environmentally responsible when we buy our newest mobile or smart device? There are steps we can all take to be more responsible towards the environment when we design our IoT projects, such as using the Three R's principle.
Reduce, Reuse, Recycle (RRR) is a concept that applies to many modern-day areas, such as building & architecture, food production, and technology, in the struggle to be more socially responsible and to address the huge amount of waste we can see growing around us.
So how should we rethink out IoT projects to comply with the Three R's principle?
Reduce: When designing the prototype of new projects, we should lower the number of new items to buy. For example, if you need a temperature sensor for your project, before ordering it online, ask your techie friends if they have a spare one. You may be amazed at how many people buy temperature sensors they do not really use.
Reducing the energy our devices consume can also be achieved, for example by reducing the clock frequency in the processor or lowering the sample rate of sensors. Put your Arduino in sleep mode for its idle periods and it can run for years on battery.
Reuse: The concept is that we should reuse existing technology as much as possible before buying a new product or gadget. Some of the GSM modules found in out-of-date mobile phones offer the same functionality you will find in a new GSM board. Most of these modules work with AT commands via a common serial interface and so do many old phones. You could also consider using the camera from a refurbished smartphone. In addition, what about the flow sensors from a damaged coffee machine or the water level sensor from a damaged washing machine? If you need a new piece of hardware, just look around - you will find it and you can boost your creativity.
Recycle: We are most familiar with this principle in our consumerist life. However, recycling is not just selecting plastic from paper; it can also be a design principle and a source of creativity. You can donate the technology you do not use anymore to be reused or refurbished, or you could hack into and reuse it yourself.
Below is a brief example of an IoT project I made from recycled technology for beekeepers.
In a beekeeper's life, the most stressful period is harvest time. Having 50 beehives out in the field for honey production means you need to know how much honey has been harvested daily and how much of it the bees have consumed for themselves. Otherwise, you can have poor production or even lose the bee colony. This is usually done by measuring the weight of the hive by placing a scale under the most representative hive and visiting it regularly. However, turning the scale into a smart IoT device means the weight data can be received from a distance, so the beekeeper will spend less time and resources monitoring its bee farm.
The hardware parts are: four load sensors, power cells, an Arduino Pro Mini, an old Nokia phone as GSM module, and an old Nokia display.
The four load sensors were collected from an old bathroom scale. Exactly the same sensors can be found for a few dollars online. The sensors were connected in a Wheatstone bridge to an HX711 industrial load cell amplifier, which is then connected to a small Arduino Arduino Pro Mini to control everything.
A display from another damaged Nokia 3310 phone is used to display the weight of the beehive on request. These phones have an 84x48 pixel monochrome display, which is why a 3.3V Arduino Pro Mini would be the easiest to use to escape the voltage divider problem.
To question the weight of the hive via SMS, an old Nokia 3410 is used as a GSM module. Some of these old Nokia phones have their own communication interface called FBus, which was used at the time for servicing the phones, but over time it was fortunately hacked for automation purposes. To use Nokia FBus I soldered three wires to the phone's Tx, Rx and Ground and wired them to Arduino's serial pins. FBus is a two-way communication with "frames", which are telegrams exchanged between the phone and the controller. The communication security consists in each telegram being acknowledged individually, a sequence counter at the end of the frame, and a double checksum calculation.
Other phones support the classic 'AT' commands for controlling the GMS module. You can find some of the new GSM chips (SIM800, SIM900) at online retail sites, but these modules not only offer the same network functionality, but also use a similar AT interface. Moreover, you can actually spend more time trying to make a new module work than you would do with an old phone, which is well documented on some hacker enthusiasts' websites.
As IoT projects and products continue to expand, now is a good time to incorporate the Three R's principle to significantly increase the reuse of existing technology.
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