E-Waste Printer Looks Nice, Prints Really, Really Small

December 5, 2014 by Rich Bremer 22 Comments

Prices of 3D Printers have certainly been falling quite a bit over the last few years. Even so, it is still, at a minimum, a few hundred dollars to get going in the hobby. [mikelllc] thought it would be a fun challenge to see if he can build a functional 3D printer for under $100.

To stay under his budget, [mikelllc] took a reasonable route and decided to use as many recycled parts as he could. In every DVD and floppy drive, there is a stepper motor, lead screw and carriage that is used to move the read/write head of the drive. These assemblies will be used to drive the 3 axes of the printer. Two DVD drives and one floppy drive were dissembled to access the needed components.

Luckily [mikelllc] has access to a laser cutter. He made the frame from 5mm acrylic sheet stock. All of the pieces have slots and tabs to ease assembly and keep everything straight and square. The motors and frames from the DVD and floppy drives are mounted to the acrylic frame pieces in strategically pre-planned holes. The Y axis is responsible for moving the print bed back and forth. It is mounted on screws so that it can be adjusted to ensure a level bed.

A little DVD drive stepper motor just isn’t powerful enough to be used as an extruder motor so a standard NEMA17 motor was purchased for this task. The motor is part of a MK7/MK8 style direct drive extruder that is made from mostly 3D printed parts. The extruder is mounted on the frame and a bowden tube guides the filament to the hot end mounted to the printer’s moving carriage. Remotely mounting the extruder motor keeps it’s mass off of the axes, which in this case may be too heavy for the small, scavenged drive stepper motors.

The electronics are standard RepRap type and the same with for the hotend. The recycled motors work well with the RepRap electronics. After all that hard work, the printable area is a mere 37mm x 37mm x 18mm, but that’s not the point of this project! [mikelllc] met his goal of building a super cheap printer from recycled parts. He has also made the extruder and laser cut frame files available for download so anyone can follow in his footsteps. If you’re digging this e-waste 3D Printer but want a larger print volume, check out this printer.

HackRF Blue

December 5, 2014 by Brian Benchoff 35 Comments

For anyone getting into the world of Software Defined Radio, the first purchase should be an RTL-SDR TV tuner. With a cheap, $20 USB TV tuner, you can listen to just about anything between 50 and 1750 MHz. You can’t send, the sample rate isn’t that great, but this USB dongle gives you everything you need to begin your explorations of the radio spectrum.

Your second Software Defined Radio purchase is a matter of contention. There are a lot of options out there for expanding a rig, and the HackRF is a serious contender to expand an SDR rig. You get 10 MHz to 6 Gigahertz operating frequency, 20 million samples per second, and the ability to transmit. You have your license, right?

Unfortunately the HackRF is a little expensive and is unavailable everywhere. [Gareth] is leading the charge and producing the HackRF Blue, a cost-reduced version of the HackRF designed by [Michael Ossmann].

The HackRF Blue’s feature set is virtually identical, and the RF performance is basically the same: both the Blue and the HackRF One can get data from 125kHz RFID cards. All software and firmware is interchangeable. If you were waiting on another run of the HackRF, here ‘ya go.

[Gareth] and the HackRF Blue team are doing something rather interesting with their crowdfunding campaign: they’re giving away Blues to underprivileged hackerspaces, with hackerspaces from Togo, Bosnia, Iran, India, and Detroit slated to get a HackRF Blue if the campaign succeeds.

Thanks [Praetorian] and [Brendan] for sending this in.

Continue reading “HackRF Blue” →

Hacklet 25 – ESP8266 WiFi Module Projects

December 5, 2014 by Adam Fabio 6 Comments

Few devices have hit the hacker/maker word with quite as large a bang as the ESP8266. [Brian] first reported a new $5 WiFi module back in August. Since then there have been an explosion of awesome projects utilizing the low-cost serial to WiFi module that is the ESP8266. This week’s Hacklet is all about some of the great ESP8266 projects we’ve found on Hackaday.io!

We start with [TM] and the ESP8266 Retro Browser. [TM] has a great tutorial on combining the ESP8266 with an Arduino Mega2560. [TM’s] goal was a simple one: create a WiFi “browser” to access Hackaday’s Retro Site. This is a bit more complex than one would first think, as the Arduino Mega2560 is a 5V board, and the ESP8266 are 3.3V parts. Level shifters to the rescue! [TM] was able to bring up the retro site in a terminal, but found that even “simple” websites like google send enough data back to swap the poor ESP8266!

Next up is [Thomas] with the Simple Native ESP8266 Smartmeter. [Thomas] has created a device to measure run time on his oil heating system. He implemented this with some native programming on the ESP8266’s onboard Diamond Standard L106 Controller. When he was done, the ‘8266 had two new AT commands, one to start measurement and one to stop. A bit of web magic with some help from openweathermap.org allows [Thomas] to plot oil burner run time against outside temperature.

[Matt Callow] is also checking out native programming using the EspressIf sdk with his project ESP8266 Native. ExpressIf made a great choice when they released the SDK for the ESP8266 back in October. [Matt] has logged his work on building and extending the demo apps from EspressIf. [Matt] has seven demo programs which do everything from blinking an LED to connecting to thingspeak via WiFi. While the demos aren’t all working yet, [Matt] is making great progress. The best part is he has all his code linked in from his Github repo. Nice work [Matt!]

[Michael O’Toole] is working on ESP8266 Development PCBs. The devboards have headers for the ESP8266, an on-board ATmega328 for Arduino Uno compatibility, and a USB to serial converter to make interfacing easy. [Michael] also provides all the important components you need to keep an ESp8266 happy, such as programming buttons, and a 3.3V regulator. We really like that [Michael] has included a header for a graphical LCD based local console.

Want to see more ESP8266 goodness? Check out our curated ESP8266 list on Hackaday.io!

Hackaday.io Update!

Hackaday.io gets better and better every day. We’ve just pushed out a new revision which includes some great updates. Search is now much improved. Try out a search, and you’ll find you can now search by project, project log, hacker, or any combination of 11 different fields. Our text editor has been revamped as well. Update a project log to give the new look a try!
We know everyone on .io is awesome, but just in case a spammer slips in, we’ve added “report as inappropriate” buttons to projects and comments. Once a few people hit those report buttons, projects or comments get sent to the admins for moderation.

That’s all the time we have for this week’s Hacklet! As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Making Embedded GUI’s Without Code

December 5, 2014 by Will Sweatman 68 Comments

When the 4D Systems display first arrived in the mail, I assumed it would be like any other touch display – get the library and start coding/debugging and maybe get stuff painted on the screen before dinner. So I installed the IDE and driver, got everything talking and then…it happened. There, on my computer screen, were the words that simply could not exist – “doesn’t require any coding at all”.

I took a step back, blinked and adjusted my glasses. The words were still there. I tapped the side of the monitor to make sure the words hadn’t somehow jumbled themselves together into such an impossible statement. But the words remained… doesn’t.require.any.coding.at.all.

Continue reading “Making Embedded GUI’s Without Code” →

Fixing A Multimeter’s Serial Interface

December 5, 2014 by Brian Benchoff 25 Comments

[Shane] bought a multimeter with the idea of using its serial output as a source for data logging. A multimeter with a serial port is a blessing, but it’s still RS-232 with bipolar voltage levels. Some modifications to the meter were required to get it working with a microcontroller, and a few bits of Python needed to be written, but [Shane] is getting useful data out of his meter.

The meter in question is a Tenma 72-7735, a lower end model that still somehow has an opto-isolated serial output. Converting the bipolar logic to TTL logic was as easy as desoldering the photodiode from the circuit and tapping the serial data out from that.

With normal logic levels, the only thing left to do was to figure out how to read the data the meter was sending. It’s a poorly documented system, but [Shane] was able to find some documentation for this meter. Having a meter output something sane, like the freaking numbers displayed on the meter would be far too simple for the designers of this tool. Instead, the serial port outputs the segments of the LCD displayed. It’s all described in a hard to read table, but [Shane] was able to whip up a little bit of Python to parse the serial stream.

It’s only a work in progress – [Shane] plans to do data logging with a microcontroller some time in the future, but at least now he has a complete understanding on how this meter works. He can read the data straight off the screen, and all the code to have a tiny micro parse this data.

Chinese Temperature/Humidity Sensor Is Easily Hacked

December 5, 2014 by Bryan Cockfield 25 Comments

There’s a new piece of electronics from China on the market now: the USR-HTW Wireless Temperature and Humidity Sensor. The device connects over Wi-Fi and serves up a webpage where the user can view various climate statistics. [Tristan] obtained one of these devices and cracked open the data stream, revealing that this sensor is easily manipulated to do his bidding.

Once the device is connected, it sends an 11-byte data stream a few times a minute on port 8899 which can be easily intercepted. [Tristan] likes the device due to the relative ease at which he could decode information, and his project log is very detailed about how he went about doing this. He notes that the antenna could easily be replaced as well, just in case the device needs increased range.

There are many great reasons a device like this would be useful, such as using it as a remote sensor (or in an array of sensors) for a homemade thermostat, or a greenhouse, or in any number of other applications. The sky’s the limit!

MicroDMA And LEDs

December 4, 2014 by Brian Benchoff 19 Comments

[Jordan] has been playing around with WS2812b RGB LED strips with TI’s Tiva and Stellaris Launchpads. He’s been using the SPI lines to drive data to the LED strip, but this method means the processor is spending a lot of time grabbing data from a memory location and shuffling it out the SPI output register. It’s a great opportunity to learn about the μDMA available on these chips, and to write a library that uses DMA to control larger numbers of LEDs than a SPI peripheral could handle with a naive bit of code.

DMA is a powerful tool – instead of wasting processor cycles on moving bits back and forth between memory and a peripheral, the DMA controller does the same thing all by its lonesome, freeing up the CPU to do real work. TI’s Tiva C series and Stellaris LaunchPads have a μDMA controller with 32 channels, each of which has four unique hardware peripherals it can interact with or used for DMA transfer.

[Jordan] wrote a simple library that can be used to control a chain of WS2812b LEDs using the SPI peripheral. It’s much faster than transferring bits to the SPI peripheral with the CPU, and updating the frames for the LED strip are easier; new frames of a LED animation can be called from the main loop, or the DMA can just start again, without wasting precious CPU cycles updating some LEDs.