Sub-$20 Arduino-Based Telemetry System

September 12, 2017 by John Baichtal 15 Comments

[William Osman] set out to prove that unlike expensive commercial data logging rigs, he could get the same results for under twenty bucks. He wanted to build a wireless three-axis accelerometer for a race car project, allowing engineers to make modifications to the suspension based on the data collected.

The hardware consists of an Arduino Pro Mini connected to a three-axis accelerometer, and an nRF24L01 wireless module. Power is supplied by the race car’s 12 V, changed to 5 V by a linear regulator with the Pro Mini in turn supplying 3.3 V. The base station consists of an Arduino and another nRF24L01 module plugged into a laptop.

The telemetry system is based on COSMOS, an open-source, realtime datalogging platform put out by Bell Aerospace. COSMOS consists of fifteen separate applications depending on how you want to view and manage your telemetry. You can download [William]’s COSMOS config files and Arduino sketch on Google Docs.

We’ve published a bunch of pieces on telemetry, like this ESP8266 telemetry project, a rocket telemetry rig, and open sourcing satellite telemetry.

[Thanks, Dennis Nestor!]

Low-cost Drift Buoy Plies The Atlantic For Nearly A Year

April 28, 2017 by Dan Maloney 34 Comments

Put a message in a bottle and toss it in the ocean, and if you’re very lucky, years later you might get a response. Drop a floating Arduino-fied buoy into the ocean and if you’ve engineered it well, it may send data back to you for even longer.

At least that’s what [Wayne] has learned since his MDBuoyProject went live with the launching of a DIY drift buoy last year. The BOM for the buoy reads like a page from the Adafruit website: Arduino Trinket, an RTC, GPS module, Iridium satellite modem, sensors, and a solar panel. Everything lives in a clear plastic dry box along with a can of desiccant and a LiPo battery.

The solar panel has a view through the case lid, and the buoy is kept upright by a long PVC boom on the bottom of the case. Two versions have been built and launched so far; alas, the Pacific buoy was lost shortly after it was launched. But the Atlantic buoy picked up the Gulf Stream and has been drifting slowly toward Europe since last summer, sending back telemetry. A future version aims to incorporate an Automatic Identification System (AIS) receiver, presumably to report the signals of AIS transponders on nearby ships as they pass.

We like the attention to detail as well as the low cost of this build. It’s a project that’s well within reach of a STEM program, akin to the many high-altitude DIY balloon projects we’ve featured before.

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Easy DIY Telemetry Goes The Distance

June 18, 2016 by Elliot Williams 11 Comments

[Paweł Spychalski] wrote in to tell us about some experiments he’s been doing, using cheap 433 MHz HC-12 radio units as a telemetry radio for his quadcopter.

In this blog post, he goes over the simple AT command set, and some of the limitations of the HC-12 part. Then he takes it out for a spin on his quadcopter, and finds out that his setup is good for 450 meters in an open field. Finally, he ties the radio into his quad’s telemetry system and tethers the other end to his cellphone through a Bluetooth unit for a sweet end-to-end system that only set him back around $20 and works as far out as 700 meters.

The secrets to [Paweł]’s success seem to be some hand-made antennas and keeping the baud rate down to a reasonable 9600 baud. We wonder if there’s room (or reason?) for improvement using a directional antenna on the ground. What say you, Hackaday Antenna Jockeys?

Also check out this very similar build where an ESP8266 replaces the Bluetooth module. And stashes it all inside a nice wooden box! Nice work all around.

PicoRico Hacks String Encoder For Bike Suspension Telemetry

May 12, 2015 by Mike Szczys 26 Comments

It’s simple, it’s elegant, and it works really really well. The PicoRico team built a telemetry system for a downhill bike. Off the top of your head how would you do this? Well, telemetry is easy… just add an IMU board and you’re golden. They went beyond that and have plans to go much further. In fact, the IMU was an afterthought. The gem of this build is a sensor that may go by several names: string encoder, draw wire sensor, stringpot, etc. But two things are for sure, they planned well for their hackathon build and they executed on that plan. This landed them as first-runners-up for the top award at the 2015 Disrupt Hackathon in New York, and the winners of the top Hackaday award at the event.

[Chris], [Marek], and [Dorian] wanted to log all the telemetry data from [Chris’] downhill bike. One of the biggest challenges is to measure the force absorbed by the suspension on the front fork. The three had seen a few attempts at this before. Those used a retractable wire like what holds keys to a custodian’s belt, mated with a potentiometer to measure the change. This is where the term stringpot comes from. The problem is that your resolution and sensitivity aren’t very reliable with this setup.

That is a sensor problem, not a mechanical problem so they kept the retractable reel and replaced the pot with a much more reliable part. In its place an AMT203 absolute position sensor provides an epic level of sensing. According to the datasheet (PDF) this SPI device senses 12 bits of rotation data, can be zeroed over the SPI bus, and is accurate to 0.2 degrees. Unfortunately we didn’t get a good up-close shot of the installation but it is shown in the video. The encoder and retractor mount above the shocks, with the string stretching down to the skewer. When the shocks actuate, the string extends and retracts, turning the absolute encoder. Combine this with the IMU (and two other IMUs they plan to add) and you’ve got a mountain of data to plot and analyze. The videos after the break show a demo of the string encoder and an interview with the team.

They came to play

It’s worth noting that the PicoRico team were in this to win it. They packed heavy for the 20-hour hackathon. Here’s a picture of all the gear they brought along with them to the event… in addition to the bike itself.

We see a solder station, Dremel (with drill press), impact driver, tap and die set, extension cords, boxes full of electronics, and more. This type of planning breaks down barriers often faced at hardware hackathons. You can download a software library; you can’t download a tool or building material that nobody has with them. This is the same lesson we learned from [Kenji Larsen] who, as part of his mentoring at the event, brought a mobile fabrication facility in a roller bag.

If you start getting into hackathons, and we hope you will, keep this in mind. Brainstorm as much as you can leading up to the event, and bring your trusted gear along for the ride.

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Hacklet 34 – Satellite Projects

February 13, 2015 by Adam Fabio 13 Comments

Space. The final frontier. Every tinkerer, hacker, and maker has dreamed of flying out of Earth’s atmosphere and into the heavens. Last year one hard-working team got a chance to fly a member to space by winning the Hackaday prize. For the rest of us, we can still experience some of that excitement by contacting satellites in orbit, or even sending a bit of our own hardware into space. This week’s Hacklet focuses on the best satellite projects on Hackaday.io!

We start with [movax] and Your satellite devkit and launch. Chipsat is a tiny satellite which runs BASIC code. Yes, BASIC in space! Chipsats will be stacked into a launcher and sent off into space in groups. The idea is to eventually have them launched from the International Space Station. Power is provided by a small solar cell which charges up a pair of super capacitors. When the capacitors are charged, the satellite will run for a few seconds. Connectivity with the ground is via a 433 MHz link. Chipsat doesn’t just float in space, three coils give it the ability to control its attitude and rotation. Chipsat will sense the space around it with a magnetometer and a light sensor.

No satellite-themed Hacklet would be complete without [Pierros Papadeas] and his team’s work on SatNOGS – Global Network of Ground Stations. SatNOGS aims to create a global network of connected satellite ground stations. Think of it as a grass-roots version of NASA’s deep space network for satellites in earth orbit. This is more than just a great idea, as SatNOGS won the 2014 Hackaday Prize. You can check out our coverage of the project back in November, 2014. Since then, the SatNOGS team has been busy! They’ve just deployed the first SatNOGS V2 system above their hackerspace in Athens, Greece.

Next up is TRSI PocketQub Satellite, another project by [movax]. TRSI is a satellite that sends data via images which can be viewed with a simple RTL-SDR stick using Hellschreiber mode. Hell mode means that images can be directly viewed in the waterfall display of whichever SDR application is running the receiver. Numbers or entire images snapped with TRSI’s cell phone style camera module can be encoded and displayed. Power is of course provided by solar cells, and the communications link will be on the coordinated 433 MHz band. The original TRSI hardware has actually morphed into a deployment machine for ChipSat, [morvax’s] other satellite project. He’s put the main TRSI program on hold until after the ChipSat campaign is complete.

Rounding out our satellite special is [OzQube] with his project QubeCast Max. QubeCast is the first Australian version of the PocketQube PQ60 satellite form factor. After watching the success of $50Sat project, [OzQube] wanted to design a satellite of his own. Since he wanted to add sensors and send more data back to Earth than previous efforts, he needed a higher data rate than the current crop of satellites. This meant going to a high-powered radio. To achieve this, he’s using a NiceRF RF4463F30 radio module. The module is based upon a Silicon Labs Si4463 RF ISM band chip, coupled with a power amplifier. The module outputs 1 watt, which is quite a bit of power for a tiny satellite!

Want more satellite goodness? Check out Hackaday.io’s freshly minted Satellite List.

The countdown is almost at 0, so that’s just about all the time we have for this episode of the Hacklet. See you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Open Sourcing Satellite Telemetry

November 25, 2014 by Brian Benchoff 5 Comments

Launched in 1978, the International Sun/Earth Explorer 3 was sent on a mission to explore the Earth’s interaction with the sun. Several years later, the spacecraft changed its name to the International Cometary Explorer, sent off to explore orbiting ice balls, and return to Earth earlier this year. Talking to that spacecraft was a huge undertaking, with crowdfunding campaigns, excursions to Arecibo, and mountains of work from a team spanning the globe. Commanding the thrusters onboard the satellite didn’t work – there was no pressure in the tanks – but still the ICE mission continues, and one of the lead radio gurus on the team has put up the telemetry parser/display crafted for the reboot project up on Github.

The guy behind the backend for the ICE/ISEE reboot project should be well-known to Hackaday readers. He’s the guy who came up with a Software Defined Radio source block for a cheap USB TV tuner, waking everyone up to the SDR game. He’s also played air traffic controller by sitting out near an airport with a laptop, and has given talks at Black Hat and DEFCON.

The ICE/ISEE-3 telemetry parser/display allows anyone to listen to the recorded telemetry frames from the satellite, check out what was actually going on, and learn how to communicate with a device without a computer that’s rapidly approaching from millions of miles away. He’s even put some telemetry recordings up on the Internet to practice.

Although the ICE/ISEE-3 reboot project will have to wait another decade or two until the probe makes its way back to our neck of the woods, [Balint] is taking it in stride an organizing a few Software Defined Radio meetups in the San Fransisco area. He just had the first meetup (Video below) where talks ranging from creating a stereo FM transmitter in GNU radio, a visual introduction to DSP for SDR and SETI signals from the Allen Telescope Array were discussed. There will be another meetup in a few weeks at Noisbridge, with some very cool subjects on the roster.

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Racing Telemetry On A Cockpit View

July 30, 2013 by Brian Benchoff 10 Comments

ODB

[Martin] has a Lotus Elise and access to a track. Sounds like fun, huh? The only problem is that the dashcam videos he makes are a little bit boring. Sure, they show him flying around the track, but without some sort of data it’s really hard to improve his driving skills. After thinking about it for a while, [Martin] decided he could use his Raspberry Pi and camera module to record videos from the dashboard of his car, and overlay engine data such as RPM, throttle, and speed right on top of the video.

Capturing video is the easy part of this build – [Martin] just connected his Raspi camera module and used the standard raspivid capture utility. Overlaying data on this captured video was a bit harder, though.

[Martin] had previously written about using the Raspi to read OBD-II data into his Raspi. Combine this with a Python script to write subtitles for his movies, and he’s off to the races, with a video and data replay of every move on the track.

The resulting movie and subtitle files can be reencoded to an HD movie. Reencoding a 13 minute HD video took 9 hours on the Raspi. We’d suggest doing this with a more powerful compy, but at least [Martin] has a great solution to fix his slightly uninformative track videos.