If You Need A Measurement Tool Just Build A Measurement Tool

[Darlan Johnson] was working on a wearable project and needed a way to measure the change in voltage and current over time. 

Most measurement tools are designed to take snapshots of a system’s state in a very small window of time, but there are few common ones designed to observe and log longer periods. It’s an interesting point, for example, many power supply related failures such as resets occur sporadically. Longer timescale measuring devices could pick these up.

[Darlan] had a ton of Feathers and shields lying around, and combined them into the needed instrument. An INA219 current sensor records the measurements. They are then displayed on a TFT and logged to an SD card. Everything is bundled into a neat 3D printed case along with a battery for wireless operation. A set of barrel connectors provide the breakout to split the wires for the current measurement.

It’s a neatly done hack and we can see it as a nice addition to any hacker’s measurement drawer.

Sensor-Laden Pigeons Gather Data For Urban Weather Modeling

When it comes to gathering environmental data in real-world settings, urban environments have to be the most challenging. Every city has nooks and crannies that create their own microenvironments, and placing enough sensors to get a decent picture of what’s going on in all of them is a tough job. But if these sensor-laden pigeons have anything to say about it, the job might get a bit easier.

The idea for using pigeons as biotelemetry platforms comes to us from the School of Geography, Earth, and Environmental Sciences at the University of Birmingham in the UK. [Rick Thomas], lead investigator on the “CityFlocks” project, explains that meteorological models are hampered by a lack of data about the air in the urban canyons formed by tall buildings. Placing a lot of fixed sensors has a prohibitive cost, and using drones to do the job would probably cause regulatory problems, especially given recent events. But pigeons are perfect for the job once they’re outfitted with an “Avian-Meteorology Instrumentation Package (AvMIP)”. From the photographs we’re guessing the AvMIP is a pretty simple data logger with GPS and inputs for the usual sensors, all powered by a small LiPo pack. Luckily, the pigeons used are all domesticated racing birds that return to the nest, so no radio transmitter is needed, but if other urban avians such as peregrine falcons and seagulls are used then a future AvMIPS might leverage pervasive WiFi networks to upload data.

It’s not the first time we’ve seen mobile platforms used to fill in gaps in weather data, of course. And if this at all puts you in mind of that time pigeons were used to guide bombs, relax – no pigeons were harmed in the making of this research project.

Thanks to [Itay Ramot] for the tip [via Gizmodo].

“DB” = Abbreviated Microcontroller Debugging

We’ve all been there. When debugging a microcontroller project, we just want to put in a print statement to figure out what’s going on with the microcontroller in real time. However, advanced embedded programmers know that printf statements are verboten: they’re just too SLOW. While not fixing this plight entirely, [Atakan Sarioglu] has come up with a clever way to create readable debug messages with minimal runtime overhead.

[Atakan Sarioglu]’s innovation, called BigBug (Github), is a dynamically-generated codebook. The codebook translates abbreviated messages sent over serial (UART here) to longer-form human-readable messages. To generate the codebook, BigBug automatically parses your comments to create a lookup between an abbreviation and the long-form message. When you are running your program on the microcontroller, BigBug will translate the short codes to long messages in real-time as you send log/debug data over serial. Continue reading ““DB” = Abbreviated Microcontroller Debugging”

Bus Pirate Commandeers I2C

The Bus Pirate is one of our favorite tool for quick-and-dirty debugging in the microcontroller world. Essentially it makes it easy to communicate with a wide variety of different chips via a serial terminal regardless of the type of bus that the microcontroller uses. Although it was intended as a time-saving prototyping device, there are a lot of real-world applications where a Bus Pirate can be employed full-time, as [Scott] shows us with his Bus Pirate data logger.

[Scott] needed to constantly measure temperature, and the parts he had on hand included an LM75A breakout board that has a temperature sensor on board. These boards communicate with I2C, so it was relatively straightforward to gather data from the serial terminal. From there, [Scott] uses a Python script to automate the process of gathering the data. The process he uses to set everything up using a Raspberry Pi is available on the project site, including the code that he used in the project.

[Scott] has already used this device for a variety of different projects around his house and it has already proven incredibly useful. If you don’t already have a Bus Pirate lying around there are a few other ways to gather temperature data, but if you have an extra one around or you were thinking about purchasing one, then [Scott]’s project is a great illustration of the versatility of this device.

Add Data To Your Shipping Suspicions With This Power-Sipping Datalogger

One only has to ship one or two things via a container, receiving them strangely damaged on the other end, before you start to wonder about your shipper. Did they open this box and sort of stomp around a bit? Did I perhaps accidentally contract a submarine instead of a boat? Did they take a detour past the sun? How could this possibly have melted?

[Jesus Echavarria]‘s friend had similar fears and suspicions about a box he is going to have shipped from Spain to China. So [Jesus] got to work and built this nice datalogger to discover the truth. Since the logger might have to go for a couple of months, it’s an exercise in low power design.

The core of the build is a humble PIC18. Its job is to take the information from an ambient light, temperature, and humidity sensor suite and dump it all to an SD card. Aside from the RTC, this is all powered from a generic LiPo power cell. The first iteration can run for 10 days on one charge, and that’s without any of the low power features of the microcontroller enabled. It should be able to go for much longer once it can put itself to sleep for a period.

It’s all housed in a 3D printed case with some magnets to stick it to shell of the shipping container. Considering the surprisingly astronomical price of commercial dataloggers, it’s a nice build!

Temperature Logger

Logging Engine Temperature For RC Models

[Rui] enjoys his remote-controlled helicopter hobby and he was looking for a way to better track the temperature of the helicopter’s engine. According to [Rui], engine temperature can affect the performance of the craft, as well as the longevity and durability of the engine. He ended up building his own temperature logger from scratch.

The data logger runs from a PIC 16F88 microcontroller mounted to a circuit board. The PIC reads temperature data from a LM35 temperature sensor. This device can detect temperatures up to 140 degrees Celsius. The temperature sensor is mounted to the engine using Arctic Alumina Silver paste. The paste acts as a glue, holding the sensor in place. The circuit also contains a Microchip 24LC512 EEPROM separated into four blocks. This allows [Rui] to easily make four separate data recordings. His data logger can record up to 15 minutes of data per memory block at two samples per second.

Three buttons on the circuit allow for control over the memory. One button selects which of the four memory banks are being accessed. A second button changes modes between reading, writing, and erasing. The third button actually starts or stops the reading or writing action. The board contains an RS232 port to read the data onto a computer. The circuit is powered via two AA batteries. Combined, these batteries don’t put out the full 5V required for the circuit. [Rui] included a DC-DC converter in order to boost the voltage up high enough.

A Simple Runner’s GPS Logger

[Daniel] received a grant from the University of Minnesota’s ECE Envision Fund and was thus responsible for creating something. He built a runner’s GPS logger, complete with a screen that will show a runner the current distance travelled, the time taken to travel that distance, and nothing else. No start/stop, no pause, nothing. Think of it as a stripped-down GPS logger, a perfect example of a minimum viable product, and a great introduction to getting maps onto a screen with an ARM micro.

The build consists of an LPC1178 ARM Cortex M3 microcontroller, a display, GPS unit, and a battery with not much else stuffed into the CNC milled case. The maps come from OpenStreetMap and are stored on a microSD card. Most of the files are available on GitHub, and the files for the case design will be uploaded shortly.

The CNC machine [Daniel] used to create the enclosure is a work of art unto itself. We featured it last year, and it’s good enough to do PCBs with 10 mil traces. Excellent work, although with that ability, we’re wondering why the PCB for the Runner’s GPS is OSH Park purple.