Author: Sharon Lin

138 Articles

ESPcopter: A Fully Customizable Drone

September 25, 2019 by 5 Comments

With so many capabilities for obstacle avoidance, the only natural progression for drones would be for them to be hand-controlled. For Turkish inventor [metehanemlik], even this wasn’t enough of a challenge, as he decided to create the ESP8266-Powered Mini Drone: ESPcopter, a programmable Arduino-compatible modular drone that is open to modding through expansion shields. Not only can DIY enthusiasts modify the algorithms used for obstacle avoidance, but the drone can be sized to whatever dimensions fit their needs.

The drone is almost entirely built from expansion shields, including the multi-ranger shield with four VL53L0x laser-ranging sensors on the forward, backward, right, and left directions of the drone. The website for the ESPcopter comes with an SDK that lets users easily modify the software running on the drone’s MCU as well as pinouts to better understand its hardware functionality. Impressively, it was fully funded through a 60-day crowdfunding campaign, and will be undergoing a second launch shortly, with some new and improved features.

Power comes from a 26 0mAh LiPo battery that allows for up to six minutes of flight time; includes a 3-axis gyroscope, accelerometer, and magnetometer; runs on an ESP8266-12S 32-bit MCU; fully charges within 45 minutes through a USB connection; weighs around 35 g; and is about 90 mm from motor to motor. Continue reading “ESPcopter: A Fully Customizable Drone” →

Fighting Household Air Pollution

September 24, 2019 by 35 Comments

When Kenyan engineer [Aloise] found out about the health risks of household air pollution, they knew there had to be a smart solution to combatting the problem while still providing a reasonable source of energy for families cooking without the luxury of cleaner fuels. Enter OpenHAP, a DIY household air pollution monitor that provides citizen scientists and researches the means to measure air particulates in developing countries.

The device is based on an ESP32 communicating with a ZH03B Particulate matter sensor over UART; a DS3231SN real-time clock (RTC), temperature and humidity sensor, and MLX90640 2D thermal sensor array over I2C; and wirelessly sending the data received to a Bluetooth low energy wrist-strap beacon and an Internet enabled phone. The device also uses a TCA9534 GPIO expander to control the visual and auditory notifiers (buzzers and LEDs) and to interface to a SD card.

The project uses the libesphttpd project modified for the ESP32 for the webserver, which is used to stream data to a mobile handset or computer using the WiFi capabilities of the ESP32. The data includes real-time sensor information, system status, storage media status, visualizations of the thermal array sensor data (to ensure the camera is facing the source of heat), and tag information to test the limits of the Bluetooth tag with regards to distance.

Power input is provided through a Micro-USB connector, protected with a TVS diode and a Schottky diode in series to prevent reverse power flow.

The project was tested in two real-life scenarios: one with a household in rural Kenya and another with an urban low-income family of four. In the first test, the family used a three stone open fire stove. A FLiR thermal camera captured the stove temperatures, while a standard camera was enough to capture the high levels of smoke inside the kitchen. The readings from OpenHAP were high enough to exceed the upper detection threshold for the particulate sensor, showing that the woman cooking in the house was receiving the equivalent of 8 cigarettes a day, about 8 x the WHO’s recommended particulate levels.

Within the second household, a typical energy mix of charcoal briquettes and kerosene was typically used for cooking, with kerosene used during the day and briquettes used at night. The results from measuring pollution levels using OpenHAP showed that the mother and child in the household regularly received around 1.5 x the recommended limit of pollutants, enough to lead to slow suffocation.

There’s already immense potential for this project to help researchers test out different energy sources for rural households, not to mention the advantage of having a portable low-energy pollution monitor for citizen scientists.

Continue reading “Fighting Household Air Pollution” →

LoRa-Based Plant Monitoring

September 23, 2019 by 28 Comments

Croatian engineers [Slaven Damjanovic] and [Marko Čalić] have developed a wireless system for farmers to monitor plant conditions and weather along their agricultural fields. The system uses an RFM95W module for LoRa communication, and devices are designed to be plug-and-play, battery-powered, and have long-range communication (up to 10km from the gateway).

It uses an ATMega328 microprocessor, and includes sensors for measuring soil moisture (FC28 sensor), leaf moisture (FC37 sensor), pressure (BME280 sensor), and air temperature and humidity (DHT22 or SHT71 sensor). The data is sent to a multichannel The Things Network  gateway that forwards the information to an external database, which then displays the data through a series of graphs and tables.

The software for sending messages to the gateway is based on the LoRa MAC in C (LMIC) and LowPower libraries and was developed by [ph2lb].

Continue reading “LoRa-Based Plant Monitoring” →

Getting The Heat On With A Thermal Camera

September 22, 2019 by 13 Comments

Need a quick way to tell your temperature before work tomorrow? Student maker [The Marpe] recently fashioned a sleek home-use thermal camera that even looks like a point and shoot. It works as an Android hardware add-on by integrating the readings from a MLX90640 far-infrared (FIR) thermal sensor with a STM32F042F6Px microcontroller. All this connects to an Android application via USB (MicroUSB or Type C).

On the app, users are able to view, take photos, and display the resulting thermal images from the open thermal camera. The code for the open Android application is also available on his GitHub.

The FIR sensors contain a small array of IR pixels, integrated to measure the ambient temperature of the internal chip, and supply sensor to measure the VDD. Each pixel on the sensor array responds to the IR energy focused on it to produce an electronic signal, which is processed by the camera processor to create a map of the apparent temperature of the object. The outputs of the sensors and VDD are stored in an internal RAM and are accessible through 3.3V I2C. They’re not only low-cost and fairly high resolution, but also available by order on Digi-Key.

The microcontroller is based on the STM32 platform, with 32-bit performance, low-power operation (at 2V to 3.6V and 48 MHz) and is fairly low-cost. The custom-designed PCBs are fitted inside a 3D-printed casing with M2.5 inserts to ease assembly. [The Marpe] used an Esra soldering iron to create a heat insert tool for easier assembly and more consistent results with the heat inserts, which made for a nicer overall finish.

The project has since been presented at the Ljublana Mini Maker Faire in Slovenia and the Trieste Mini Maker Faire in Italy. Here, the open thermal camera is being tested out on a faulty PCB with a shorted component, showing the location of the short on the Android application’s thermal camera display.

Other uses for the camera could be home insulation inspection, water leakage detection, wildlife observation, or even figuring out if your soldering iron is hot enough to use. We’ll say it’s a pretty useful DIY project!

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Can You Read Me The Time?

September 21, 2019 by 11 Comments

If you’re like the average clock user, you’ve probably gotten annoyed at reading analog clocks before. Typically, the solution is just to use a digital timepiece, but [sjm4306] has opted to make a small word clock that you can carry with you wherever you go to remind you of the time in the English language.

Unlike a similar project made by [Gordan Williams], which uses an 8 x 8 LED matrix with an inkjet printed overlay, this small word clock uses a 3D-printed light box to achieve its letter matrix. In fact, they were inspired by all of the existing DIY word clock designs using anything from off-the-shelf LED arrays, transparency masks and WS2812s.

The design uses a home-brewed PCB design that runs off 5 V via USB. The design places the letters on the top stop and restricts layers to keep the solder mask and copper from obstructing the light. The bottom side uses the same design principle with a square shape that overlaps the letter. In order to block light between adjacent letters, the 3D-printed light box comes into play.

One design challenge for the letter matrix was fitting all possible minutes into the array. Rather than making a larger array of letters, [sjm4306] had the clock describe the time down to five-minute intervals then add asterisks for the full time. It’s a pretty understandable solution for keeping the design simple, and the letters all fit onto the design so well!

Using a pin map assigned to the I/O for the rows and columns of the array, the software toggles the states of the pins as a switch statement. For scanning the matrix, the software uses an interrupt that draws the current column of LEDs and updates the display image before incrementing to the next column. By skipping or not skipping cycles, this allows the display to look brighter or dimmer.

The time tracking is fairly simple, using a DS1302 serial real time clock chip – it even charges a super capacitor to keep time after power is removed!

To tackle the light scattered internally in the PCB’s FR4 material, a separator is used to contain the light. As a low-cost solution, while there is still some amount of light diffused, it’s definitely better than without the separator.

Almost all of the files used for building the small word clock are available on [sjm4306]’s project page, including the software and design files. It hopefully won’t be too long before we start seeing more of these low-cost word clock designs!

Continue reading “Can You Read Me The Time?” →

Airport Runways And Hashtags — How To Become A Social Engineer

August 23, 2019 by 11 Comments

Of the $11.7 million companies lose to cyber attacks each year, an estimated 90% begin with a phone call or a chat with support, showing that the human factor is clearly an important facet of security and that security training is seriously lacking in most companies. Between open-source intelligence (OSINT) — the data the leaks out to public sources just waiting to be collected — and social engineering — manipulating people into telling you what you want to know — there’s much about information security that nothing to do with a strong login credentials or VPNs.

There’s great training available if you know where to look. The first time I heard about WISP (Women in Security and Privacy) was last June on Twitter when they announced their first-ever DEFCON Scholarship. As one of 57 lucky participants, I had the chance to attend my first DEFCON and Black Hat, and learn about their organization.

Apart from awarding scholarships to security conferences, WISP also runs regional workshops in lockpicking, security research, cryptography, and other security-related topics. They recently hosted an OSINT and Social Engineering talk in San Francisco, where Rachel Tobac (three-time DEFCON Social Engineering CTF winner and WISP Board Member) spoke about Robert Cialdini’s principles of persuasion and their relevance in social engineering.

Cialdini is a psychologist known for his writings on how persuasion works — one of the core skills of social engineering. It is important to note that while Cialdini’s principles are being applied in the context of social engineering, they are also useful for other means of persuasion, such as bartering for a better price at an open market or convincing a child to finish their vegetables. It is recommended that they are used for legal purposes and that they result in positive consequences for targets. Let’s work through the major points from Tobac’s talk and see if we can learn a little bit about this craft.

Continue reading “Airport Runways And Hashtags — How To Become A Social Engineer” →