Repairing a MakerBot Mightyboard Clone

It can be argued that MakerBot, a company that makes popular 3D printers, hit its pinnacle with the introduction of the Replicator 2. It was designed well and completely open source, including the motherboard that drove the printer – known as the Mightyboard. China quickly picked up on the success of the Replicator 2 and copy/pasted several of their own versions (at a much cheaper sale price). One of these outfits is called Wanhao, and their version of the Replicator 2 is called..wait for it…the Duplicator!

Their version of the Mighyboard is identical to the original, minus a few nickle and dime components. This suggests that Wanhao made an effort to cut as much cost as possible without looking at what functionality they were removing. And anytime a company does this, you can bet the quality of the board manufacturer is at the bottom of the barrel.   [Avrydev] found this out the hard way when he repaired a faulty motherboard from a broken Duplicator.

The board would not connect to the software via USB, and the startup tune pitch was off. [Arvydev] flashed new firmware via ICSP, but that did not help. He eventually clued in on the main crystal for the Atmega processor. A quick swap and presto! The printer is as good as new.

Manned Multicopter Project Undaunted By Crash

We have to be impressed by [amazingdiyprojects] who completely totaled their manned multi-copter build, which has been spanning over eight videos. He explained the crash in video number eight and is right back at it, learning from the recent mistakes.

When you get right down to it, this is as dangerous as this seems. However, a giant multicopter is probably the easiest flying machine for a hobbyist to build. It’s an inefficient brute-force approach, but it sure beats trying to build a helicopter from scratch. This machine is a phenomenally un-aerodynamic chair on a frame that has a lot in common with the lunar rover; with engines on it. Simple.

There are a lot of approaches to this. One of the crazier ones is this contraption with a silly amount of electric motors. [amazingdiyprojects] went with eight gasoline engines. We’re really interested in his method for controlling the rpm of each engine and dealing with the non-linearity of the response from a IC engine throttle. Then feeding that all back into what is probably the exact same electronics from a regular diy drone.

Honestly, we’re surprised it worked, and we can’t wait for him to finish it so we can see him zooming around in his danger chair. Videos after the break.

Thanks [jeepman32] for the tip!

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Hacklet 95 – More Pi Zero Contest Entries

We’re well into the second week of the Hackaday and Adafruit ultimate team-up: The Raspberry Pi Zero Contest. The entries have been flying in! As of Thursday evening, we have 70 projects vying for one of 10 Raspberry Pi Zeros, and one of three $100 gift certificates to The Hackaday Store. This week on The Hacklet, we’re going to take a look at a few more contest entries.

blueberryWe start with [Sean Hodgins] and Blueberry Zero – Keep your Pi in your Pocket. [Sean] can’t leave home without his Raspberry Pi Zero. Carrying all the cables, adapters, and accessories required to power up a tiny Linux computer can be a chore though. He’s created a solution to simplify all that with Blueberry Zero. This custom PCB hat contains an HC-05 style Bluetooth module connected to the Pi’s console port. Serial alone doesn’t make for a standalone Pi, so [Sean] added a LiPo battery and charger chip. A switching power supply boosts the 4.2 V LiPo output up to the 5 V required for the Pi. Now when [Sean] just has to hack out some python code, all he needs to do is open a Bluetooth connection from a cell phone, tablet, or computer.

pcpower[Doihaveto] is using his Pi Zero to manage a desktop PC. PC Power allows him to not only turn his computer on or off, but to disconnect the mains power completely. [Doihaveto’s] PC does have Wake On Lan, but he’s run into problems when the system has failed. His Pi provides an extra layer of protection in case things don’t wake up as expected. The board contains two optoisolated connections to a host PC. One is the power switch output, the other is the power LED input. If all else fails, PC Power also can control a solid state relay to completely isolate the computer from mains power. PC Power uses a web interface created with Python using the flask web framework.

pifoldNext up is [tomwsmf] with PiFold. Like [Sean] up above, [tomwsmf] can’t leave home without his Pi Zero. Rather than hacking code though, [tomwsmf] is serving up media. PiFold is a wallet containing a Pi Zero powered server. The Anyfesto software package runs on the Pi, serving up songs and files via WiFi. Audio is also transmitted on 88.1 MHz FM via PiFM. A 2500 mAh battery pack coupled with a boost converter keeps PiFold humming away. When the battery needs a charge, [tomwsmf] can use a small solar panel to top up the battery while staying green.



retrorobotFinally, we have [Fredrik J] with Retrofit Robot. The 1980’s were a golden age of toy robots from Japan. Tomy, Nikko, and a few other companies created devices like Omnibot, which were ahead of their time. [Fredrick] still has his vintage Nikko RC-ROBOT, but it has long since ceased to function. The Pi Zero presents a perfect opportunity to give the little guy a new lease on life. [Fredrik’s] goal is to keep the RC-ROBOT’s original look while giving him new functions. The old DC motors are being replaced with closed loop servos. The servos will be controlled by an Adafruit 16 channel servo driver board. The next step for Retrofit Robot is a big 6000 mAh battery. We can’t wait to see how this one turns out!

If you want to see more entrants to Hackaday and Adafruit’s Pi Zero contest, check out the submissions list! If you don’t see your project on that list, you don’t have to contact me, just submit it to the Pi Zero Contest! That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of!

Flexible Phototransistor Will Make Everything Subtly Better In The Future

University of Wisconsin-Madison is doing some really cool stuff with phototransistors. This is one of those developments that will subtly improve all our devices. Phototransistors are ubiquitous in our lives. It’s near impossible to walk anywhere without one collecting some of your photons.

The first obvious advantage of a flexible grid of phototransistors is the ability to fit the sensor array to any desired shape. For example, in a digital camera the optics are designed to focus a “round” picture on a flat sensor. If we had a curved surface, we could capture more light without having to choose between discarding light, compensating with software, or suffering the various optical distortions.

Another advantage of the University’s new manufacturing approach is the “flip-transfer” construction method they came up with. They propound that their method produces a vastly more sensitive device. The sensing silicon sits on the front of the assembly without any obstructing material in front; also the metal substrate it was built on before flipping is reflective; also increasing the sensitivity.

All in all very cool, and we can’t wait for phone cameras, with super flat lenses, infinite focus, have no low light capture issues, and all the other cool stuff coming out of the labs these days.

Deaccelerating The Apple IIc Plus

The Apple IIc Plus is arguably – very arguably from my experience – the best Apple II computer ever made. It’s portable, faster than the IIe, had a much higher capacity built-in drive, and since the Plus could run at 4MHz, it was faster than the strange eight or sixteen bit Apple IIGS. Recently, [Quinn] has been fascinated with the IIc Plus, and has gone so far as to build a custom gamepad and turn the IIc Plus into a laptop. Now, she’s turned her attention to the few things Apple got wrong with the Apple IIc Plus – the startup beep and defaulting to 4MHz on every boot instead of Apple II’s standard 1MHz that’s used in the Apple II, II Plus, IIe, and IIc non-Plus.

The original Apple II is surprisingly primitive. Apart from writing a loop of NOPs and counting cycles, there’s no way to keep time. There is no clock, no timer, no tick counters, and no interrupts. If you’re writing a game for the Apple II that depends on precise timing, the best you’ll be able to manage is a delay loop. This worked for a time, until the Apple IIc Plus was released with a default clock of 4MHz. It was a great idea for AppleWorks and other productivity apps, but [Quinn] is doing retrocomputing, and that means games. Booting the Apple IIc Plus into its 1MHz mode means turning it on and holding escape while resetting the computer every time. It’s very annoying, but a mod to make the IIc Plus run at 1MHz by default would turn her into one of the most accomplished currently active Apple II developers.

The process of booting into the IIc Plus’ 1MHz mode requires holding down escape while restarting the computer. This should tell you something: it’s not a hardware switch that changes speed. It’s in the ROM, and that means diving into the Technical Reference Manual, looking at the listings in the ROM monitor, and figuring out how everything works.

The IIc Plus ROM is incredibly complex – it’s 32k of hand assembled code with jump tables bouncing everywhere. After a ton of research, [Quinn] successfully reverse engineered the ‘slow down if the ESC key is pressed’ routine, allowing her to boot the machine at 1MHz by default, and 4MHz if there’s a soft reset with the option key pressed. Everything works great, and [Quinn] has the video to prove it

This isn’t [Quinn]’s first attempt at hacking the lowest levels of the Apple IIc Plus ROM. Because the IIc Plus ran at 4MHz by default, the startup beep was so very wrong. She fixed that, and with two very useful patches under her belt, she burned a few new chips with her ROM patches. In total, there’s only a few dozen bytes of hers in the new 32k ROM, but that’s enough to make her one of the top current firmware developers for the Apple II platform.

Brushed DC Servo Drive

Brushless DC motors, and their associated drive electronics, tend to be expensive and complicated. [Ottoragam] was looking for a cheaper alternative and built this Brushed DC motor servo controller and the results look pretty promising. Check out the video after the break.

He needed a low cost, closed loop drive for his home-brew CNC. The servo drive is able to supply a brushed DC motor with up to 7 A continuous current at up to 36 V which works out to about 250 W or 1/3 HP. It does closed loop control with feedback from a quadrature encoder. The drive accepts simple STEP and DIRECTION signals making it easy to interface with micro controllers and use it as a replacement for stepper motors in positioning applications. All of the control is handled by an ATmega328P. It takes the input signals and encoder data, does PID control, and drives the motor via the DRV8701 full bridge MOSFET driver. There’s also some error detection for motor over-current and driver under-voltage. Four IRFH7545 MOSFETs in H-bridge configuration form the output power stage.

This is still work in progress, and [Ottoragam] has a few features pending in his wish list. The important ones include adding a serial interface to make it easy to adjust the PID parameters and creating a GUI to make the adjustment easier. The project is Open Source and all source files available at his Github repository. The board is mostly surface mount, but the passives are all 0805, so it ought to be easy to assemble. The QFN footprint for the micro controller could be the only tricky one. [Ottoragam] would love to have some beta testers for his boards, and maybe some helpful comments to improve his design.

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Glitching Square Wave Clock Is Designed To Confuse

[Voja Antonic] has built a clock that tells the time in binary with square waves, and trolls the uninitiated in electronics.

The clock itself is very attractive. If you look closely you can see the circuitry backlit behind the dot LED matrix display. The whole thing is housed in a nicely folded steel case. RGB LEDs are used to good effect to highlight some additionally obfuscating circuit schematics. The workmanship is very top notch, and we would gladly host such an object on our desks.

The clock’s standard time telling mode is three sets of square waves showing the binary values for the hours, minutes, and seconds. Every now and then the clock will glitch out. The waves will distort. The colors will change. And every now and then, tantalizingly, the alpha-numeric time will show up for just a split second, before returning to those weird squiggles again.

We’ve seen a whole slew of binary clocks before. This one, for instance. But the waveform display makes us feel just that little bit more at home — it’s just like we’re sitting in front of our oscilloscope.