BBQ Thermometers Get Serious

February 8, 2016 by Al Williams 12 Comments

You can write with a fifty cent disposable pen. Or you can write with a $350 Montblanc. The words are the same, but many people will tell you there is something different about the Montblanc. Maybe that’s how [armin] feels about meat thermometers. His version uses a Raspberry Pi and has a lengthy feature list:

8 Channel data logging
Plotting
Webcam (USB or Raspicam)
Alarms via a local beeper, Web, WhatsApp, or e-mail
Temperature and fan control using a PID
LCD display

You can even use a Pi Zero for a light version. There’s plenty of information on Hackaday.io, although the full details are only in German for the moment. As you can see in the video below, this isn’t your dollar store meat thermometer.

Even though a disposable pen does the same job as a Montblanc, most of us would rather have a Montblanc (although Hackday would have to hand out some pretty steep raises before we start using the Meisterstück Solitaire Blue Hour Skeleton 149).

We might have done more with an ESP8266 and then done more work on the client, but we have to admit, this is one feature-packed thermometer. We’ve seen simpler ones that use Bluetooth before, along with some hacks of commercial units.

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Robo Car Via 3G

February 7, 2016 by Al Williams 20 Comments

[Emil Kalstø] has a pretty solid remote control car. We don’t mean a little car with a handheld remote you can drive around the neighborhood. [Emil’s] car has a camera and a cell phone so that it can go anywhere there’s 3G or 4G networking available.

The video (see below) shows the results (along with [Emil’s] little brother acting as a safety officer). The video offers tantalizing detail you might find useful if you want to reproduce a similar vehicle. However, it stops short of providing complete details.

The two batteries onboard will power the vehicle for over 20 hours of continuous use. The 30W motor is reduced with a chain drive to go about “walking speed.” There’s a Raspberry Pi with a Huawei 3G USB dongle onboard and [Emil] uses an XBox controller to do the steering from the warmth of his living room. Of course, a Pi can’t handle a big motor like that directly, so a Phidgets USB motor controller does the hard work. The software is written using Node.js.

The camera mount can swivel 230 degrees on a servo so that the operator can scan the road ahead. The video mentions that steering the car required a heavy-duty servo with metal gears (an earlier attempt with nylon gears didn’t work out).

Overall, it looks like a solid build. We hope [Emil] will share code and more details soon. If you can’t wait (and your insurance is paid up), you might have a go at an even bigger car. Surprisingly, there’s more than one example of that.

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New Angle On Raspberry Pi Zero Hub

February 6, 2016 by Rud Merriam 48 Comments

Collectively, the Hackaday readers sigh, “Not another Pi Zero hub!!!”. But [Sean Hodgins’] hub is different. It has a new angle, literally. Besides, it’s an entry in the Hackaday and Adafruit Pi Zero Contest .

[Sean Hodgins’] acute approach is orthogonal to most of the other hubs we’ve seen. He’s mating the hub at right angles to the Zero. The hub plugs into both the on-the-go USB port and the USB power port. No extra cables or wiring needed. [Sean] plans to release the design on GitHub after his Kickstarter campaign ends. He’s supplying bare boards for those who like the smell of solder paste.

This project nicely triangulates the issues of adding a hub to the Zero. The physical connection is solid with the boards connecting via the USB connectors. Power is supplied through the hub the way the Pi expects, which means all the protections the Pi Foundation built into the onboard conditioning are left in place. This also reduces surge problems that might occur when back powering through a hub and hot swapping USB devices. Another neat feature is the notched corner leaving the HDMI port accessible. Similarly, the Pi’s GPIO pins are free of encumbrance. One drawback is the hub is fused at 2 amps, just like the Pi. It would be nice to have a little more headroom for power hungry USB devices. Maybe another 0.5 amp to allow for the Zero’s usage.

[Sean] snaps the two together after the break.

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Code Craft: Cross Compiling For The Raspberry Pi

February 3, 2016 by Rud Merriam 48 Comments

Sometimes there’s just no place like your desktop. You’ve already got your favorite development tools and references setup or installed and it’s a pain when you’re trying to work on an unfamiliar, or simply uncustomized, system. On your desktop everything is at your fingertips. If you want to search the web, the browser is just an alt-tab away. If you need a calculator, it’s right there to run. Your editor highlights syntax in your favorite colors already.

When developing on a Raspberry Pi, you leave all these creature comforts behind unless you spend the time to configure the Pi to your liking. Then it all gets wiped when you install a new distribution, like the recent change from Wheezy to Jessie. Even then it’s frustrating to switch back and forth between the desktop and the Pi because there is always something on the other system that you need. My usual comment is, “dirty word”, literally.

Cross-developing on your desktop is a very workable solution. We’re going to walk through setting up your desktop and a Pi to do this. This means loading a Pi ARM toolchain on your desktop and a debugging server on the Pi. This’ll let you develop and debug from in the comfort of your desktop. An added advantage is when you put that Pi in a robot you can debug over a wireless link.

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Cramming A Pi Zero Into A USB Hub

February 1, 2016 by James Hobson 41 Comments

We kinda feel bad posting all these awesome hacks you can do with a Raspberry Pi Zero when we know most of our audience here probably doesn’t have one due to the backlog of orders… but regardless — here’s another one you can try — if you have one anyway. A Raspberry Pi USB Hub!

In case you didn’t know, Amazon has a series of electronics accessories called Amazon Basics — and they’re actually pretty good quality accessories. One of them is a 7-port, 4A USB hub. Looking at this [gittenlucky] figured he might just have enough room to fit a Pi Zero inside… and as it turns out. He did.

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Fingerprint Scanner For Laptop And Raspberry Pi (or Giving The Finger To Your Computer)

January 29, 2016 by Rud Merriam 28 Comments

We’ve got two hacks in one from [Serge Rabyking] on fingerprint scanning. Just before leaving on a trip he bought a laptop on the cheap. He didn’t pay much attention to the features and was disappointed it didn’t have a fingerprint scanner. Working in Linux he uses sudo a lot and typing the password is a hassle. Previously he just swiped his finger on the scanner and execution continued.

He found a cheap replacement fingerprint scanner on hacker’s heaven, also known as eBay. It had four wires attached to a 16 pin connector. Investigation on the scanner end showed the outer pair were power and ground which made [Serge] suspect it was a USB device. Wiring up a USB connector and trying it the device was recognized but with a lot of errors. He swapped the signal lines and everything was perfect. He had sudo at his finger tip.

Next he wonder if it would work with a Raspberry Pi. He installed the necessary fingerprint scanning software, ran the enrollment for a finger, and it, not terribly surprisingly, worked.

On Linux the command fprintd-enroll reads and stores the fingerprint information. By default it scans and saves the right index finger but all ten fingers can be scanned and stored. Use libpam-fprintd to enable account login using a finger. Anyone know how you can trigger other events using a different finger? A quick search didn’t turn up any results.

In true hacker style, [Serge] created his own fingerprint reader from a replacement part. But you can jump start your finger usage by purchasing one of many inexpensive available readers.

Turning A Lapdock Into A Laptop With The Pi Zero

January 26, 2016 by James Hobson 25 Comments

Do you remember the Motorola Lapdock 100? It was a CPU-less laptop designed for plugging in your smartphone that enabled you to use your phone as a computer! Perhaps a bit ahead of its time, they never really caught on — but now you can buy them pretty cheap, and with the release of the Raspberry Pi Zero, it was only a matter of time before someone combined the two.

The Lapdock 100 has long been a useful accessory for the Raspberry Pi, but until the Zero came out, it was always a messy bundle of wires running to and from the devices, making it a less than ideal solution. The Zero changes everything. [Ax0n] knew he had to try combining the two.

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