A black PCB with an ESP32 and an SBM-20 geiger counter

Flexible Radiation Monitoring System Speaks LoRa And WiFi

September 10, 2022 by Robin Kearey 12 Comments

Radioactivity has always been a fascinating phenomenon for anyone interested in physics, and as a result we’ve featured many radioactivity-related projects on these pages over the years. More recently however, fears of nuclear disaster have prompted many hackers to look into environmental radiation monitoring. [Malte] was one of those looking to upgrade the radiation monitor on his weather station, but found the options for wireless geiger counters a bit limited.

So he decided to build himself his own Wifi and LoRa compatible environmental radiation monitor. Like most such projects it’s based on the ubiquitous Soviet-made SBM-20 GM tube, although the design also supports the Chinese J305βγ model. In either case, the tube’s operating voltage is generated by a discrete-transistor based oscillator which boosts the board’s 5 V supply to around 400 V with the help of an inductor and a voltage multiplier.

Graphs showing temperature, humidity and radiation levels — Data can be visualized in graphs, together with other data from the weather station like temperature and humidity

The tube’s output signal is converted into clean digital pulses to be counted by either an ESP32 or a Moteino R6, depending on the choice of wireless protocol. The ESP can make its data available through a web interface using its WiFi interface, while the Moteino can communicate through LoRa and sends out its data using MQTT. The resulting data is a counts-per-minute value which can be converted into an equivalent dose in Sievert using a simple conversion formula.

All design files are available on [Malte]’s website, including a PCB layout that neatly fits inside standard waterproof enclosures. Getting more radiation monitors out in the field can only be a good thing, as we found out when we tried to detect a radiation accident using community-sourced data back in 2019. Don’t like WiFi or LoRa? There’s plenty of other ways to connect your GM tubes to the internet.

2022 Hackaday Prize: Plant Monitoring System Grows To Include LoRa

August 23, 2022 by Bryan Cockfield 7 Comments

Change on industrial scales is slow, but if you’re operating your own small farm or simply working in a home garden there are some excellent ways to use water more effectively. The latest tool from [YJ] makes it possible to use much less water while still keeping plant yields high.

This is an improvement on a previous project which automates watering and lighting of a small area or single pot. This latest creation, called FLORA, includes a LoRa module for communication up to 3 kilometers, and the ESP32 on board also handles monitoring of soil moisture, humidity and other sensors. It also includes a pump driver for managing irrigation systems so that smart decisions can be made about when to water. Using this device, the water usage when testing was reduced by around 30% compared to a typical timed irrigation system.

Using a smart system like this is effective for basically any supply of water, but for those who get water from something like an off-grid rainwater system or an expensive water utility, the gains are immediate. If you aren’t already growing your own food to take advantage of tools like this, take a look at this primer to get you started.

Ask Hackaday: How Can You Store Energy At Home?

August 16, 2022 by Maya Posch 156 Comments

Amidst the discussions about grid-level energy storage solutions, it is often easy to forget that energy storage can be done on the level of a single house or building as well. The advantages here are that no grid management is needed, with the storage (electrical, thermal, etc.) absorbing the energy as it becomes available, and discharging it when requested. This simplifies the scale of the problem and thus the associated costs significantly.

Perhaps the most common examples of such systems are solar thermal collectors with an associated hot water storage tank, and of course batteries. More recently, the idea of using a battery electric vehicle (BEV, ‘electric car’) as part of a home storage solution is also gaining traction, especially for emergencies where the grid connection has failed due to a storm or similar emergencies. But all-in-all, we don’t see many options for home-level energy storage.

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Hackaday Prize 2022: Solar Power Through Pyrolysis

August 12, 2022 by Jenny List 19 Comments

We’re all familiar with solar cells, be they photovoltaic, or for heating water. But they are only the more common ways of converting the sun’s energey into usable power, and to the extended list there is now an addition courtesy of [Dennis]. He’s using the sun to drive the pyrolysis of biomass waste, releasing hydrogen fuel.

For those who aren’t familiar with the chemistry, pyrolysis refers to chemical reactions triggered by heat. In this case, when organic biomass is heated in the absence of oxygen it breaks down and releases the gaseous products of that breakdown as well as a mass of carbon. The idea behind this pyrolysis cell is that a Fresnel lens will focus the sun on a reaction chamber, providing the required heat for the reaction to occur. A test with a magnifier and a test tube proves that there’s something in it.

Of course, sharp-eyed readers will notice that this isn’t quite in the same vein as other cells which convert the Sun’s energy into a usable form, in that while it provides an input of energy for the pyrolysis the chemical energy in the resulting gas comes mostly from the original biomass. There is a silver lining to the prospect of burning gas though, in that the left-over carbon can be incorporated into the soil as biochar, an effective carbon sink.

We’ve seen a project pursuing a similar chemistry before, though not using solar energy to do it.

Hackaday Prize 2022: DIY Brushless Hand Cranked Generator

August 6, 2022 by Jenny List 12 Comments

A standard part of travel kit for the 2020s is now a battery pack — a hefty lithium-ion cell with onboard electronics for USB charging, that ensures all of our devices stay topped up while we’re out of range of a socket. But what happens when there is no handy mains supply to recharge it from? Step in [Chleba], with a hand cranked generator.

There are plenty of hand cranked generators to be found online, from tiny devices intended to top up a single phone to sturdy metal boxes intended for battery charging. This one differs from those in that most use a brushed DC motor as a cheap generator, while here that function comes from a stepper motor feeding a rectifier pack and thence a DC-to-DC converter. A step-up gearbox provides the necessary shaft speed, and a neat 3D-printed case rounds everything off.

The result is about as neat a generator as you could imagine, and would certainly be of use shoved into any off-grid backpack. Meanwhile it’s not the first we’ve shown you, we’ve even see one that could start a car.

Maximum Power Point Tracking: Optimizing Solar Panels

August 3, 2022 by Maya Posch 59 Comments

When looking at integrating a photovoltaic solar panel into a project, the naive assumption would be that you simply point the panel into the general direction of where the Sun is, and out comes gobs of clean DC power, ready to be used for charging a battery. To a certain extent this assumption is correct, but feeding a solar panel’s output into something like a regular old PWM buck or boost regulator is unlikely to get you anywhere close to the panel’s full specifications.

The keywords here are ‘maximum power point’ (MPP), which refers to the optimal point on the solar panel’s I-V curve. This is a property that’s important not only with photovoltaics, but also with wind turbines and other highly variable power sources. The tracking of this maximum power point is what is generally referred to as ‘MPPT‘, but within this one acronym many different algorithms are covered, each with its own advantages and disadvantages. In this article we’ll take a look at what these MPPT algorithms are, and when you would want to pick a particular one.

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Watering The Garden With A Solar-Powered System

July 22, 2022 by Lewin Day 18 Comments

Watering the garden is important to do regularly if you want your plants to thrive. [Nikodem Bartnik] built a system to handle it for him, keeping his garden on the grow.

The system has an Arduino commanding an irrigation system based around a pump delivering water from a reservoir. It’s paired with a water level sensor to keep an eye on the water available to the system. Moisture sensors are also used to monitor the prevailing soil conditions, to ensure the plants aren’t over- or under-watered. In this case, [Nikodem] designed his own resistive moisture sensors, which proved difficult but taught him a lot along the way. verything was then wrapped up in a food container to make it waterproof for installation outside. A solar panel and charging system was also installed to power the whole setup without requiring a mains connection.

While this system worked, the moisture sensors were a bit unreliable and there was a lot of cabling involved. A second revision got rid of the sensors and used a Pi Pico to implement a simple timer-based irrigation scheme.

Either way, both systems worked and helped keep the vital water flowing to the garden bed. Automatic plant watering is a bit of a popular theme around here, and we’ve seen some nifty hacks in that realm of late. Video after the break.

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