Hacklet 31 – Software Tools

For every computer error, there are two human errors, and one of them is blaming the computer. Whenever a human blames a computer for something, there are two tools, and one of them is the computer.

Not all of your nifty tools need to be fancy robots, CNC machines, or nifty Robertson screwdrivers; a computer is equally capable of being a fantastic tool, provided it has the right software. For this week’s Hacklet, we’re going through some of the best software tools on hackaday.io.

6653681421957570397[Alan] was inspired to build a software tool for making sewing patterns. Sewing patterns are usually designed for the ‘average’ person, but if you’re making custom wearables, you should end up with a piece of clothing that fits perfectly.

The first project [Alan] is using this tool for is a fleece cap that fits the contour of his head. He captured a 3D mesh of his head, imported the mesh into Blender, and unwrapped the resulting mesh. The two halves of the hat were then plotted with a Silhouette Cameo, cut out of fleece, and sewn together. The result is a beanie that fits perfectly around [Alan]’s head. It’s an extremely cool and novel application of 3D modeling, and if you ever need to wrap a 3D object with a 2D material, this is the project you want to check out.

5869061407871295021 And you thought the autorouter in Eagle was bad.

[Anderson] built a tool called Pyrite that will take a schematic and build a layout in three-dimensional space. He calls them Volumetric Circuits, and it’s basically the point-to-point wiring found in old radios and amplifiers taken to the next level. We featured this project before, and there haven’t been many updates since then. Maybe giving [Anderson]’s project a few skulls will help motivate him to get back to the project.

133031421839442989 Not satisfied with the existing free and open source CAM programs, [Snegovick] started work on his own.

[Snegovick] calls his project BCAM, and it’s exactly what you need to mill holes in PCBs, cut gears with a CNC router, engrave plastic, and anything else a 2.5 axis CNC machine can do. The project is written in Python, and yes, the source is available. Supported operations include drilling, path following, offset path following, and pocketing.

Write enough microcontroller projects, and you’ll eventually come up with your own library of common code that does one thing and one thing well. If you’re smart, you’ll reuse that code in future projects. [ericwazhung] is cutting through the hard part of developing all this code and released some things that are useful in a whole lot of projects.

Included in the commonCode library are the usual ‘heartbeat LED’, non-blocking input, a standard interface for AVR timers, bitmaps of text characters, DC motor control, and a whole bunch more. Extremely useful in any event.

That’s it for this round of the Hacklet, bringing you the best hackaday.io has to offer.

Flashing Chips With A CNC

[Eberhard] needed to flash several hundred ATMegas for a project he was working on. This was a problem, but the task did have a few things going for it that made automation easy. The boards the ‘Megas were soldered to weren’t depanelized yet, and he had a neat and weird bed of nails programming connector. There was also a CNC machine close by. This sounds like the ideal situation for automation, and it turns out the setup was pretty easy.

The boards in question were for FPV/radio control telemetry adapter and thankfully the assembly house didn’t depanelize the 40 PCBs on each board before shipping them out. A very cool ATMega flashing tool handled the electrical connections between the computer and the microcontroller, but a real, live human being was still required to move this flashing tool from one chip to the next, upload the firmware, and repeat the process all over again.

The solution came by putting a few metal pins in the bed of a CNC mill, 3D print an adapter for the flashing tool, and writing a little code to move the flashing tool from one chip to the next. An extremely simple app takes care of moving the programmer to an unflashed chip, uploading the firmware, and continuing on to the next chip.

There’s still some work to be done that would basically tie together the Gcode and AVRdude commands into a single interface, but even now a complete panel of 40 PCBs can be programmed in a little over 10 minutes. You can check out a video of that below.

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Transferring Audio to an AVR at 12kbps

Back in the bad ‘ol days of computing, hard drives cost as much as a car, and floppy drives were incredibly expensive. The solution to this data storage problem offered by all the manufacturers was simple – an audio cassette. It’s an elegant solution to a storage problem, and something that has applications today.

[Jari] was working on a wearable message badge with an 8-pin ATTiny. To get data onto this device, he looked at his options and couldn’t find anything good; USB needs two pins and the firmware takes up 1/4 of the Flash, UART isn’t available on every computer, and Bluetooth and WiFi are expensive and complicated. This left using audio to send digital data as the simplest solution.

[Jari] went through a ton of Wikipedia articles to figure out the best modulation scheme for transferring data with audio. What he came up with is very simple: just a square wave that’s changed by turning a pin off and on. When the audio is three samples long without crossing zero, the data is 0. When it’s five samples long without crossing zero, the data is 1. There’s a 17-sample long sync pulse, and with a small circuit that acts as a zero crossing detector, [Jari] had a simple circuit that would transfer data easily and cheaply.

All the code for this extremely cheap modem is available on GitHub.

Phoenard, A Prototyping Gadget

The Hackaday Prize party wasn’t just about the five finalists; actually, there were more THP entries in attendance – All Yarns Are Beautiful, OpenExposer, M.A.R.S., a 3D scanner, and a few more that I’m forgetting – than actual finalists. In addition, a number of people brought projects that had never seen the light of day, like [Ralf] and [Pamungkas]’ Phoenard.

Phoenard is a Kickstarter project the guys launched at the prize party, something they could attend as a little side trip after manning the ‘maker’ part of the Atmel booth at Electronica. They’ve come up with a tiny handheld device that can only be described as a ‘gadget’. It has a touchscreen, a battery, an MegaAVR, a few connectors, and not much else. What makes this project cool is how they’re running their applications. A bootloader sits on the AVR, but all the applications – everything from a GSM phone to an MP3 player – lives on a microSD card.

The Phoenard guys have come up with a few expansion modules for Bluetooth LE, GSM, GPS, and all the usual cool modules. Plugging one of these modules into the back of the device adds capability, and if that isn’t enough, there’s an old 30-pin iPhone connector on the bottom ready to accept a prototyping board.

Video of these guys below.

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Hackaday Links: November 9, 2014

After many years of searching, [Dan Wood] finally got his hands on something he’s wanted for the past twenty-two years: an Amiga 4000. No, it’s not the queen bee of Amiga land – that honor would fall to the 68060-equipped 4000T, but [Dan]’s 4000 is decked out. It has a 256MB RAM expansion, Ethernet, USB, and a Picasso IV graphics card that gives it better resolution and color depth than most modern laptops.

[Pistonpedal] has a fully automatic pneumatic can crusher that is far too cool to be wasted on a case of Keystone. A funnel at the top guides the cans in to be crushed one at a time and ejected into a garbage can underneath. Great for recycling.

Coming over from ‘normal’ programming into the world of embedded development? [AndreJ] has the AVR C Macro for you. It’s a great way to get away from all those ~=, |=, and &=s that don’t make any sense at all.

[CNLohr] has a reputation for running Minecraft servers on things that don’t make any sense at all. The latest build is a light up redstone ore block equipped with an ESP8266 WiFi chip.

Oh, the Hackaday overlords and underlings are in Munich for this little shindig we’re doing. If you in town for Electronica come on down. If you have a copy of Neil Young’s Trans, bring it to the party.

Inexpensive AVR Programmer Made From Five Components

If you want to program an AVR chip as inexpensively as possible, then [Ian’s] solution might just be for you. He built an AVR programmer using only four components. This design is based on the vusbtiny AVR programmer design, with a few components left out.

[Ian’s] design leaves out two of the resistors and two diodes, leaving just four components. These include a 1.5k resistor, a small capacitor, a USB connector, a six pin header, and an ATtiny45. He admits that this may not be exactly up to USB spec, but it does work.

This is one of those projects that is really an exercise in “will it work?” more than anything else. The fact that you need to first program an AVR chip means that this wouldn’t be useful in a pinch, because you would already have to have a working programmer. Nonetheless, it’s always fun to see what can be done with as little as possible.

The Most Basic BASIC Computer

avr computer

AVR microcontrollers can do pretty much anything nowadays. Blinking LEDs, handling sensor inputs, engine control modules, and now, thanks to [Dan], a small single chip BASIC computer with only ten parts (and four of them are capacitors).

[Dan]’s homebrew computer has it all. The ATmega 1284P microcontroller outputs a composite video signal and handles inputs from a PS/2 keyboard. The microcontroller runs at 16 MHz, has 7 kB of memory for programs, and can use a separate EEPROM to store data. It also has an array of GPIO pins for interacting with the physical world.

For software, the microcontroller runs a version of BASIC called Tiny BASIC plus, which is a stripped-down language that can fit in 3 kB of memory. This is crucial if you’re in the 1970s or if you’re programming on an AVR microcontroller in the 21st century.

We’ve seen other Arduinos and AVR-type microcontrollers that can run BASIC, but this one has a great form factor and clean look. It’s also a great way to get familiar with homebrew computing and the BASIC programming language!