Tindie

I’ve been slowly adding more gadgets to my home automation setup. I typically use voice control, but I’ve been searching for a nicely packaged interface for controlling devices, and the HA SwitchPlate from Derusha Digital Designs is a very clean and modern looking home automation controller. Designed to fit into an existing lightswitch box, it uses a 2.4″ TFT touchscreen display for interaction.

The GUI looks very well-designed and easy to navigate. The HASP has been designed to work with Home-Assistant.io or openHAB, but because it uses MQTT it can easily work with just about any existing home automation solution. With the help of websites like IFTTT, it could be leveraged to control devices that are part of your Google Home ecosystem, for example.

The designers are quick to point out that this is not a drop-in solution; you will have to do some legwork and setup to integrate it into existing systems. This is the controller for the hacker, not the consumer. Despite this, it has the polished look of a consumer product, which is a great selling point.

I’m very impressed with their excellent documentation. It covers basic set-up and integration with Home-Assistant, as well as pointers for how to integrate with other systems. I’m pretty confident that any hacker who has worked with MQTT before will have no problem. As an open-source project, you can also dig into the source code to modify it however you wish. I’m sure that many end users will want to make changes to the GUI to include new features, or change the colour scheme, etc. The code is written as an Arduino sketch for the ESP8266, and it is well-commented and easy to read.

Overall, this looks like an excellent solution, and one I am strongly considering using one in my own apartment! Kudos to Derusha Digital Designs for such a slick and clean design.

If you need an MQTT debugging tool, I’d like to give a shoutout to MQTTCute, an excellent tool designed by my friend and Hackaday contributor Maya Posch. I’ve used it many times for MQTT projects and it’s a great tool for quickly subscribing and publishing to MQTT topics.

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The Sensiron STS35 temperature sensor is a factory calibrated digital temperature sensor, with accuracy of ±0.1°C. As with any sensor, having a breakout board is important, but this ClosedCube STS35 breakout board ticks all the right boxes for me.

The designer of a breakout board needs to understand the potential applications, and the most important things a developer might want to change. For a temperature sensor, it’s important to have the sensor physically isolated from the rest of the circuitry to ensure the measured temperature is correct. This is taken care of by putting the sensor on its own little island of PCB, with a thin section of PCB connecting it to the breakout pins. This helps isolate it thermally.

Because this sensor uses I2C, another important thing developers might want to change is the I2C address. Including a DIP switch for address changing shows that the designer understands what people want to do with this sensor (using multiples on the same I2C bus). The DIP switch also allows you to enable and disable the I2C pull-up resistors in they case they’re already included in the microcontroller board you plan to attach to this.

I love seeing well-thought out boards like this. The differences might seem trivial, but when you are in the middle of a debug session, little touches like this can make the job so much easier. The small size is also important, allowing the developer to take advantage of the small size of the sensor itself. There’s nothing more annoying than a temperature sensor in the middle of a huge PCB!

The best part of all? The price includes two of these breakouts, meaning you can take advantage of the I2C address changes and daisy-chain them together. The sensor accepts voltages from 2.5-5.5V, which easily handles 2.5V, 3.3V and 5V logic. It also has a resolution of 0.01°C and has an ALERT output which can drive a microcontroller interrupt line in case the temperature goes outside of pre-defined ranges.

If you’re looking for a small, reliable and high-accuracy temperature sensor, the STS35 is a great choice, and this breakout board is an excellent way to develop with it!

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E-paper displays are remarkable for a few different reasons. Extremely high contrast, viewable in direct sunlight, and the most popular feature: zero power draw to maintain the display. This means you can set a display, put your microcontroller into super deep sleep, and use a few nanoamps at most to keep a readable display.

This awesome e-paper development board features the Particle P1 WiFi module, which contains a Cypress WiFi chip and an ST Cortex-M3 microcontroller with 1MB of flash. The e-paper display is 1.54″ with a resolution of 200×200 pixels. The model number of the exact e-paper display used is not shown in the description, but it’s definitely an SPI-driven display from GoodDisplay; likely the GDEH0154D67. A built-in LiPo charger is an excellent addition, making this usable as an IoT display development platform.

E-paper is an excellent partner to IoT as the low power requirements of epaper pair well with limited battery capacity designs common with IoT devices. The combination of WiFi and epaper allows low-power dynamic displays to become more ubiquitous, allowing more convenient access to daily data, i.e. calendars, weather, stocks and news. The GitHub repository comes with example code for a weather display, a simple clock, and using the Particle P1’s functions.

This board sparks all sorts of project ideas in my head. Creating a portable home automation controller; a small note-keeping display magnet for a fridge… I’ve wanted to hack on e-paper displays, and this module is a great way to do so, while also having options for wireless connectivity!

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As an amateur radio operator, I am always keeping an eye out for cool new radio-related things to tinker with. Hams have a long tradition of building and designing their own radios, and it’s great to see this still happening in the digital era. This DSP-based radio can receive SSB (single sideband) over almost the entire amateur HF band. This band spans from 1.9 MHz (also called 160 meters) all the way up to 28 MHz (10 meters) and everything in between.

This is a great radio for portable use. Paired with a small CW (continuous wave, the mode used for Morse code) transmitter, it would make a great QRP set for those who love low-power Morse communication. Bandwidth can be adjusted from 500Hz to 4kHz, which is perfect for CW as well as digital modes. The designer specifically designed it to be used with the extremely popular new digital mode FT-8, and it indeed fits the specifications very well. It could also be used for many other digital modes, including PSK, RTTY, JT65, and many more! The audio output can be wired directly into any PC — even a Raspberry Pi — to enable digital reception modes.

Remember that just listening does not require an amateur license — only transmitting does! That means you can legally use this board to listen to anything you can receive. It’s a great way to dip your toe in the waters of amateur radio, and see if you like it.

The on-board lithium polymer battery charger is a great feature, making it even easier to make into a portable receiver. Add a project box and a decently sized battery, and you will be receiving for many hours! Unfortunately, an antenna is not included with the board. Antennas for reception are not hard to come by though, and are much less expensive than antennas designed for transmitting.

Be careful, though — the amateur radio bug is impossible to get rid of once it bites you!

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Why use WiFi when a physical link can do the job? Using a wired link is often more reliable and removes some security risks associated with wireless access. And what better cable for the job than the ubiquitous, time-tested RS-232? This dual-outlet metal junction box contains RS-232 control electronics to give any device that can speak serial control over the output.

WiFi devices have increased exponentially in popularity over the past 5 years. A larger and larger percentage of the population have WiFi controlled lighting, heating, appliances, and even door locks. The convenience is hard to beat, but wireless communications that aren’t properly secured can be exploited by an attacker. In most domestic use cases, the results would be more annoying than catastrophic. In an industrial setting, on the other hand, the consequences could be much more severe depending on the equipment being controlled. Wireless automation has made progress in industrial equipment, but many factories and workshops still prefer to use wired connections.

RS-232 was introduced all the way back in 1960, but wasn’t standardized until 1969. It can support near real-time speeds, making it ideal for applications that require low latency communication, such as power switching. Though modern computers often don’t have DE-9 serial ports, USB to DE-9 dongles are cheap and commonplace. Some ATX motherboards still have serial ports, and PCI express serial port cards are another option as well.  Serial communication has been tried and tested for over 50 years and is extremely reliable when implemented properly.

This power box may not find its way into the average consumer’s home, but it might be really handy to have in your electronics lab. You could set it up to power all your test equipment, and have it remotely turn them on when needed. It could also see use in amateur radio, where remote usage of base stations has grown in popularity. This box would make an excellent way to power up a radio via computer control.

Whatever the use cases you are thinking of, this box can handle up to 2200W! For safety, we would suggest sticking to under 1200W, especially on 120V. Pretty beefy though! The metal case is an excellent upgrade over common plastic junction boxes. It looks rugged and built-to-last!

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Recently, I wrote a post about this awesome replica PCB for the Commodore Amiga 500 series. That same designer has now released a similar replica PCB for the Amiga’s older sister, the Commodore 64!

The “SixtyClone” comes in two different flavours, depending on which era of 64 you are trying to repair (or create from scratch!). The older design uses chips which are slightly easier to get, but has a less reliable design (according to Commodore enthusiasts). The newer design reduced the number of logic chips, but some of the chips — such as the less common 2x32kb RAM chips — are much more difficult to obtain. Despite this, it is considered the superior design with less complexity and higher reliability.

Why offer these boards in the first place? As many vintage computers age, they tend to have capacitors and/or backup batteries which leak, causing corrosion damage to the PCB. Sometimes it’s possible to clean and repair, but in many cases the corrosion has eaten through internal copper layers, and repair can be a hair-pulling exercise in futility. Having a brand new, tested, and reliably made replacement board can make refurbishing older machines much easier and less frustrating!

Look at that beautiful design and silkscreen!

As he did with the Amiga replicas, Bob’s Bits has improved the silkscreen design, making it easier to read and with better placement and naming of component labels. He has also made a few small tweaks to the layout, in order to improve a few small design elements that were likely rushed on the Commodore 64.

As a bonus, his Tindie store also sells optional extras to help repair a damaged or old 64. He stocks resistor and capacitor packs which have every capacitor and resistor needed to populate the replacement board. As of this writing, the older style board is sold out, but there are still quite a few of the newer design available. Keep checking back to see when new stock comes in!

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While not every hacker has a vector network analyzer on their bench, those into the RF side of things likely do. VNAs have long had a cloud of mystery about them, due to their (at a glance) unintelligible display output. However, they are in essence a very simple pair of instruments: a signal generator, and a signal analyzer. One of the outputs sends out an RF signal, which goes through the device under test, and then back into the input of the VNA. It can then see how the device affects the signal, and if any power is reflected back into the output of the VNA. This allows designers to test RF components, like antennas and filters.

However, the average VNA was, for a long time, a very expensive piece of equipment, reserved only for the telecom labs and research facilities. Over the last decade or so, the prices have fallen to the point that RF hobbyists can start to use them. The NanoVNA smashes through the existing price floor, bringing a 3GHz VNA to the market for under $60.

While the specs won’t be winning any awards, the device is still very usable for RF hobbyists and amateur radio operators in particular. Being USB-powered, it’s possible to use it with a powerbank, making a portable unit which is perfect for field testing. There is also on-board charge circuitry, so the end-user can add a lithium-ion battery pack to the unit and make it self-contained!

A bonus is the software packages that it can work with — namely this very cool open source VNA package. This allows further analysis to be done on a PC, opening up more detailed and advanced measurement capabilities.

If you are into RF design, check out the NanaVNA V2 and let us know what you think!

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GPS modules are coming down in price, with cheaper units made overseas being available for under $10. However, they come with some disadvantages. They typically have lower accuracy, and worse reception. This means it takes a lot longer to get an initial fix, like the GPS receivers from the 1990s which needed an open sky and many minutes.

But a recent chipset from Mediatek has improved in both areas. It is more accurate and more sensitive. This GPS receiver board from elektronic-idee pairs the new Mediatek MT3333 chipset with a beefy antenna connector. With the included antenna, it’s possible to get decent GPS reception indoors. This makes it an ideal partner to a GPS-disciplined clock source for your home lab. Even a high-quality rubidium oscillator can be improved by adding GPS discipline. You will see an even bigger difference when pairing it with either a temperature compensated or oven controlled quartz oscillator. (Psst, the same seller actually sells a pre-made GPS-disciplined oscillator that integrates this same GPS chipset!)

This receiver supports 33 channels of tracking with 99 channels for acquisition. It supports both GPS and GLONASS, as well as various SBAS (Satellite-based Augmentation Systems) which can, in certain parts of the world, give more accurate location fixes and timing outputs. In this category, it supports both current and future American, Japanese, and European augmentation systems.

It can give accurate position data using as little as 7mA! Even in full-power tracking mode, the GPS module only uses 23mA. This is an order of magnitude better than older generation chipsets, and can dramatically increase battery life. This makes options like solar or energy harvesting viable.

The chipset boasts an active interference canceller, and a built-in logging function. This is the perfect chipset to use in low-power IoT solutions that need location data. As a bonus, the seller includes an active GPS antenna which supports 3.3 or 5V (though the board itself runs at 3.3V) that will improve signal reception. Compared to passive antennas, the difference can be amazing, especially when indoors or when line-of-sight to the sky is impeded.

If you’ve been looking for a low-power, high-accuracy GPS receiver, or if you’ve been wanting to add GPS discipline to your lab oscillator, this board is a great choice!

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Ah, USB Power Delivery, my favourite part of the new USB-C specification. Finally, high-speed charging through reversible USB cables! It’s great to see more hackers using USB PD in their USB-C designs, and this is a nifty little charging upgrade for Lenovo Thinkpad laptops. The downsides of older laptop charging systems are having a proprietary cable, and the fragility of barrel connectors over time. Using USB-C as a laptop charging cable is a great idea, which many modern laptops have started to incorporate. But why not bring that new technology to existing laptops?

Many laptops end up with broken or worn-out charging cables (you should see mine — it’s a big mess of heat shrink and hot glue). A replacement power supply from the manufacturer can be as much as $150! Using third-party power supplies is possible with some manufacturers, but my Dell laptop has a secret serial connection to the charger, which it uses to query and find out if the charger is genuine. If it doesn’t respond, or if the cable breaks (grumble grumble) the laptop will run at a reduced clock speed, and it won’t charge the battery. What a pain!

Luckily, Handy Tools of Taiwan has created this replacement module that converts a range of laptop charging ports to USB-C. It is aimed at the Thinkpad X220 and X230, but there are a variety of different Lenovo laptops that use the same power connector. Be sure to check the power rating of your existing power brick and order the correct replacement! You will also need to pick up a USB-C wall adapter that supports Power Delivery at the voltage and current your device needs. These are becoming more common, and prices are falling, so that shouldn’t be too difficult! Note that Handy Tools also offers a similar replacement module for another range of Lenovo laptops. Very cool!

If you are curious about the Power Delivery spec, I highly recommend checking out the USB Implementer’s Forum PDF about Power Delivery. It’s amazing to me that they have released this spec for free — no yearly fees for access to their specs! This enables hackers like Handy Tools to easily create devices which can interface with existing USB PD chargers and take advantage of their flexible output voltages.

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Power banks are ubiquitous, and because they offer 5V with an easy to use USB port, they often find use in wireless projects. IoT projects in particular often take advantage of the high power density and small form factor. But most power banks have a feature to turn themselves off when the attached device (presumed to be a phone or other device that requires charging) reaches full charge. They do this by sensing the current draw, watching for it to fall below a certain threshold.

This can be a major issue for projects with a low, steady standby current, which also need bursts of high current when transmitting. This smart device helps keep your power bank from switching off when your device is not drawing much current — and it does it without drawing excessive power!

This design takes advantage of the fact that before shutting off due to low current draw, power banks have a delay of 5-10 seconds. By drawing very small pulses of current every few seconds, the circuitry is kept awake. The amount of energy actually used is completely configurable, depending on your individual power bank. You can have it draw up to 140mA for any length of time, at intervals which are also customizable. This allows it to be used with a wide variety of power banks.

Sure, some power banks don’t have this feature, or might have a cutoff which is below what your device draws. But finding the perfect power bank could be a costly and difficult endeavour, when you can just use whatever power bank is the most economical paired with this device!

The source code and design files are freely available for modification from GitHub. Happy hacking!

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