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.

A weatherproof enclosure, opened to show a supercapacitor-based system inside

Wireless Weather Station Gets Solar-Powered Supercap Upgrade

April 7, 2022 by Robin Kearey 18 Comments

When [knight-of-ni] bought an Acurite Atlas weather station to replace his earlier 5-in-1 model, he was initally happy with its performance. However, after just ten months the batteries in the outdoor unit died; since the previous model would happily run for several years on one charge, this was a bit of a bummer. Climbing up on the roof more than once a year just to replace batteries was becoming inconvenient as well, so [knight-of-ni] designed a solar power system with supercap backup and remote monitoring that should keep the sensors running 24/7, come rain or shine.

The heart of the new power system is a pair of supercapacitors totalling 250 Farads, with an integrated protection circuit that limits the voltage to 5.4 Volts. The caps are charged by a 12 V solar panel; this means that quite a bit of power is dissipated in the protection circuit when the supercaps are fully charged, but since this is completely free solar power that is not much of an issue. A 6 V panel would have worked as well in full sunlight, but might have struggled on a cloudy or snowy day.

[knight-of-ni] wasn’t content with just letting the new power system run unattended however, and decided to integrate a remote monitoring tool as well. For this he used a Moteino, which is an Arduino-type board with an integrated 915 MHz transceiver. The data coming from this board is received by a Raspberry Pi running Linux and presented through a nice web interface. Thanks to this data [knight-of-ni] was able to confirm that the supercaps were fully charged in just an hour and a half on a sunny morning, and maybe three or four times that on a dark and rainy day.

If you’re interested in solar-powered weather stations, we’ve featured a few: some very simple, some more comprehensive, and one built into an IKEA lantern. If you’d like a recap on the working principle of supercapacitors and how they compare to batteries, look no further than our in-depth article on supercaps.

Thanks for the tip, [felix]!

Wemo Smart Plug Gets Brain Transplant

December 1, 2020 by Tom Nardi 17 Comments

Like many modern smart home gadgets, Belkin’s Wemo brand of smart plugs has a tendency to phone home every time you turn on a lamp. [Gigawatts] wasn’t having it, so they figured out how to flash the device with OpenWRT and replicated its original functionality with a web interface. Unfortunately this stopped working after awhile, and rather than trying to diagnose the issue, it seemed the time would be better spent simplifying the whole thing.

As [Gigawatts] explains, there are actually two separate boards inside the Wemo plug. One holds the relay to do the high-voltage switching, and the other provides the control. They are linked with a three wire connector, making it exceptionally simple to swap out the original controller for something different. The connector supplies 5 V and ground, all you’ve got to do is pull the third wire high to flick the switch.

While the ESP8266 probably would have been the first choice for many a Hackaday reader, [Gigawatts] actually went with the Moteino, a low-power Arduino compatible board with integrated RFM69 transceiver. With an LED to indicate status and a few lines of code tweaked, the Moteino got this once WiFi-only smart plug speaking a new language.

There’s some debate over how effective smart plugs are from an energy efficiency standpoint, but even if this reborn Wemo doesn’t help [Gigawatts] save much power, at least it won’t be blabbing about everything to a third-party.

Compact Controllers Automate Window Blinds

May 24, 2016 by Dan Maloney 26 Comments

Commercially available motorized window blinds are a nice high-end touch for today’s automated home, but they tend to command a premium price. Seems silly to charge so much for what amounts to a gear motor and controller, which is why [James Wilcox] took matters into his own hands and came up with this simple and cheap wireless blind control.

[James] started his project the sensible way, with a thorough analysis of the problem. Once COTS alternatives were eliminated – six windows would have been $1200 – he came up with a list of deliverables, including tilting to pre-determined positions, tilt-syncing across multiple windows, and long battery life. The hardware in the head rail of each blind ended up being a Moteino on a custom PCB for the drivers, a $2 stepper motor, and a four-AA battery pack. The Moteino in one blind talks to a BeagleBone Black over USB and wirelessly to the other windows for coordinated control. As for battery life, [James] capitalized on the Moteino’s low-power Listen Mode to reduce the current draw by about three orders of magnitude, which should equate to a few years between battery changes. And he did it all for only about $40 a window.

Window blinds seem to be a tempting target for hacking, whether it’s motorizing regular blinds or interfacing commercial motorized units into a home automation system. We like how compact this build is, and wonder if it could be offered as an aftermarket add-on for manual blinds.

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RFM69 To MQTT Gateway On The Super-Cheap

November 14, 2015 by Elliot Williams 10 Comments

[Martin] is working on a RFM69-to-MQTT bridge device. If you’re at all interested in DIY home automation, this is going to be worth following. Why? When your home automation network gets big enough, you’re going to have to think seriously about how the different parts talk to each other. There are a number of ways to handle this messaging problem, but MQTT is certainly a contender.

MQTT is a “lightweight” publish-subscribe framework that’s aimed at machine-to-machine data sharing, and runs on top of a normal TCP/IP network. IBM has been a mover behind MQTT since the beginning, and now Amazon is using it too.

But most MQTT servers need a TCP/IP network, which pretty much means WiFi, and this can be a killer for remote sensors that you’d like to run on battery power, or with limited processing power. For these use cases, a low-power, simple sub-gigahertz radio module is a better choice than WiFi. But then how to do you get your low-power radios to speak to your MQTT devices?

That’s the point of [Martin]’s MQTT bridge. Previously he had built a sub-gig radio add-on for a Raspberry Pi, and let the Pi handle the networking. But it looks like there’s enough processing power in a lowly ESP8266 to handle the MQTT side of things (over WiFi, naturally). Which means that you could now connect your 868 MHz radio devices to MQTT for less than the cost of two pumpkin spice, double-pump lattes.

On the firmware side, [Martin] has enlisted the help of [Felix], who developed the Arduino-plus-RFM69 project, the Moteino. [Felix] has apparently ported his RFM69 library to the ESP8266. We’re dying to see this working.

For now, we’ve got some suggestive screenshots which hint at some LAN-exposed configuration screens. We’re especially interested in the RFM + MQTT debug console window, which should really help in figuring out what’s gone wrong in a system that spans two radio protocols.

The bottom line of all of this? Super-cheap, power-efficient RFM69-based radio nodes can talk with your sophisticated MQTT network. Keep your eyes on this project.

Blink Thrice To Let Me In

April 8, 2015 by James Hobson 52 Comments

Now here’s a really cool home hack. [Luis Rodrigues] has automated his garage door to open, simply by flashing his headlights at it.

But wait, doesn’t that mean anyone could break into his house? Nope. At first we thought he had just added some photo-sensors and a bit of computer logic in order to turn a pattern of lights into an output to open the garage, but no, it’s actually specific to his car only. Which is awesome because if anyone ever tried to copy him to break in, all they break into is a very confused state of mind.

You see how it actually works is the headlight output is connected to a control box under the hood of his car. A Moteino (RF Arduino variant) reads the input signal of the headlights flashing three times, and then communicates wirelessly to the garage door in order to open it.

But [Luis] also has a gate outside his property — so if you hold the lights on for a second, both the garage door and the external gate will open as well.

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THP Hacker Bio: Felix Rusu

September 12, 2014 by Brian Benchoff 10 Comments

As far as entries for The Hackaday Prize go, Moteino is exceptionally interesting. It’s the only project to be used in other projects for The Hackaday Prize. The two other projects making use of the Moteino, 433MHz transceiver and Plant Friends didn’t make the cut, but [Felix]’s Moteino did.

Like many of the Internet of Things project, Moteino is a radio module and a microcontroller in an extremely convenient package. The radio is a HopeRF RFM69 operating in the 315, 433, 868 and 915MHz ISM bands. The microcontroller is everyone’s favorite – the ATMega328, but [Felix] also has a Mega version with the ATMega1284 on board. Already there are a few great examples of what the Moteino can do, including a mailbox notifier, a sump pump monitor, and a way to Internetify a water meter.

[Felix]’s bio below.

Continue reading “THP Hacker Bio: Felix Rusu” →