The magnetic compass has been a crucial navigational tool for around a thousand years or so, perhaps longer. While classical versions still work perfectly well, you can now get digital magnetometers that work in much the same way. [mircemk] decided to whip up a digital compass to demonstrate the value of these parts.

The build uses a HMC5883L magnetometer. While this can detect magnetic fields in three axes, just one is necessary for building a device that operates akin to a traditional compass. The output of the device is read by an Arduino Nano, which is hooked up to a string of WS2812B LEDs and a small OLED display. The LEDs display the bearing of magnetic north, while the OLED screen shows the current angle between the compass’s arrow and magnetic north.

It’s a tidy build that would be a great educational resource for teaching both electronics and navigational skills. We’ve seen similar projects before, like the hilarious Pizza Compass. Video after the break.

Consider an analog or even digital compass. While you can reasonably expect either to point towards magnetic north when held flat, when you add tilt and/or roll to the equation, things get a bit wonky. That is unless you’re maker “lingib,” who was able to construct a magical compass using an Arduino Uno and an MPU-9250 IMU unit, with an accelerometer/gyro in the same package.

As seen in the video below, when the compass unit is set at an angle, the heading output varies significantly—as much as 100 degrees according to the project write-up. When stabilization is turned on, however, the gyro/accelerometer is used to compensate for magnetometer heading variations—reducing output errors to just a few degrees.

This Instructable explains how to make a tilt compensated compass using an Arduino Uno R3, an LCD display, and an IvenSense MPU-9250 multi-chip-module that contains an MPU-6050 accelerometer / gyro and an AK8963 magnetometer within the same package.

The LCD simultaneously displays the heading, (P)itch, and (R)oll.

The heading accuracy is within 2 degrees depending on how well the compass has been calibrated.

Without tilt compensation the compass headings vary significantly … sometimes by as much as 100 degrees.

When stabilised, the tilted compass headings only vary by one or two degrees … the improvement is amazing.

The tilt stabilization may be disabled by placing a jumper wire between Arduino pins A0 and GND.

A conventional compass points north (well, to magnetic north, anyway). [Videoschmideo]  wanted to make a compass that pointed somewhere specific. In particular, the compass — a wedding gift — was to point to a park where the newlywed couple got engaged. Like waking up in a fresh new Minecraft world, this is their spawn point and now they can always find their way back from the wilderness.

The device uses an Arduino, a GPS module, a compass, and a servo motor. Being a wedding gift, it also needs to meet certain aesthetic sensibilities. The device is in an attractive wooden box and uses stylish brass gears. The gears allow the servo motor to turn more than 360 degrees (and the software limits the rotation to 360 degrees). You can see a video of the device in operation, below.

The compass module may be hard to find, but you should be able to modify it to work with more readily available boards. Since you may not be able to find the exact gears used, your build will probably be a little different anyway.

The brass and wood are decidedly steampunk looking. It reminded us of this GPS project. If you have too much street cred to buy an off-the-shelf GPS, you could always roll your own.

Coffee, good food, bar? Sometimes it’s hard to explore a new city and choose among hundreds options without spoiling it! A team of students at CIID (Grishma Rao, Justine Syen, Adriana Chiaia, Jivitesh Ranglani) created Pilgrim, a MKR1000-based device providing a tangible interface for discovery without a digital screen. Acting like a smart compass, Pilgrim points people in the direction of a desired location, sourcing data directly from the Yelp API and leading to an eventual unexpected discovery:

The experience begins with the selection of a category using a dial below the compass, that clicks to send out data. The proximity to the destination is then indicated by lights along the rim of the compass, that light up one by one as the person gets closer to the location.

Once a category selection is received via clicking the dial, the code queries the Yelp API to return the coordinates of the best matched result to Pilgrim. The magnetic needle would then turn an angle relative to the user’s current position, replacing magnetic north with coordinates of the destination.

Pilgrim is programmed with a Genuino MKR 1000 which enables the compass to be connected to internet and also has a higher amount of memory. Moreover, Pilgrim uses a magnetometer + accelerometer for the directions, a stepper motor with an H-bridge, and a rotary encoder for the dial.

Giant wristwatches are so hot right now. This is a good thing, because it means they’re available at many price points. Aim just low enough on the scale and you can have a pre-constructed chassis for building your own smartwatch. That’s exactly what [benhur] did, combining a GY-87 10-DOF module, an I²C OLED display, and an Arduino Pro Mini.

The watch uses one button to cycle through its different modes. Date and time are up first, naturally. The next screen shows the current temperature, altitude, and barometric pressure. Compass mode is after that, and then a readout showing your step count and kilocalories burned.

In previous iterations, the watch communicated over Bluetooth to Windows Phone, but it drew too much power. With each new hardware rev, [benhur] made significant strides in battery life, going from one hour to fourteen to a full twenty-fours.

Take the full tour of [benhur]’s smartwatch after the break. He’s open to ideas for the next generation, so share your insight with him in the comments. We’d like to see some kind of feedback system that tells us when we’ve been pounding away at the Model M for too long. 

[via Embedded Lab]

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Hi all, I'm Matt and currently a junior in high school. I built first robot called the "A.S.R.B." over the summer for the Authentic Science Reseach Program and I wanted to share it with all of you! *I'm going to apologize in advanced if my spelling/wording/grammar is terrible--It's been a long day and I'm in a rush to get this posted.* Using the chassis of the duratrax evader EXT-2, I built this robot from the ground up.  I swapped out the esc and dc motor for a traxxas 12t 550 that I had lying around, and the esc is now the traxxas xl-5.

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Hello LMR,

This is one of my robots that I have been working on for a while. I have'nt posted it yet because I wanted to make sure I have a lot done. I use the lynxmotion A4WD1 as the base. 

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Using this tutorial, I set up my new HMC5883l compass module from china onto my robot, and I had a simple program to draw the readings onto a circle.

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Autonomous Robot - GPS, Tilt Compass, Arduino Mega, Wild Thumper Motor Controller, Wild Thumper Chassis.