Author Archives: Donald Papp

Life on Contract: How Much Do I Charge?

Posted on by

If you’re comfortable with the technical side of becoming a consultant or contractor but are unsure what to charge for your services, you’re not alone. “How much do I charge?” is a tough question, made even tougher by the fact that discussing money can be awkward, and at times virtually taboo.

As a result it’s not uncommon for the issue to get put off because it’s outside one’s comfort zone. Technical people in particular tend to suffer from an “if you build it, they will come” mentality; we get the technical side of things all figured out and just sort …read more

Continue reading Life on Contract: How Much Do I Charge?→

Making an Arduino Shield PCB with Fritzing

Posted on by

[Allan Schwartz] decided to document his experience using Fritzing to design, fabricate, and test a custom Arduino shield PCB, and his step-by-step documentation makes the workflow very clear. Anyone who is curious or has been looking for an opportunity to get started will find [Allan]’s process useful to follow. The PCB in question has two shift registers, eight LEDs, eight buttons, and fits onto an Arduino; it’s just complex enough to demonstrate useful design features and methods while remaining accessible.

[Allan] starts with a basic breadboard design, draws a schematic, prototypes the circuit, then designs the PCB and orders it …read more

Continue reading Making an Arduino Shield PCB with Fritzing→

Dumb Box? Make it Really Smart!

Posted on by

[Stephen Harrison]’s Really Smart Box is a great concept, it’s simultaneously a simple idea while at the same time being super clever. The Really Smart Box isn’t really a box; it’s a drop-in platform that can be made any size, intended to turn any dumb storage box into one that helps manage and track levels and usage of any sort of stock or consumable.

It does this by measuring the weight of the stuff piled on top of it, while also monitoring temperature and humidity. The platform communicates this information wirelessly to a back end, allowing decisions to be made …read more

Continue reading Dumb Box? Make it Really Smart!→

Gorgeous Engineering Inside Wheels of a Robotic Trail Buddy

Posted on by

Robots are great in general, and [taylor] is currently working on something a bit unusual: a 3D printed explorer robot to autonomously follow outdoor trails, named Rover. Rover is still under development, and [taylor] recently completed the drive system and body designs, all shared via OnShape.

Rover has 3D printed 4.3:1 reduction planetary gearboxes embedded into each wheel, with off the shelf bearings and brushless motors. A Raspberry Pi sits in the driver’s seat, and the goal is to use a version of NVIDA’s TrailNet framework for GPS-free navigation of paths. As a result, [taylor] hopes to end up with …read more

Continue reading Gorgeous Engineering Inside Wheels of a Robotic Trail Buddy→

Problems that Plagued an Edible Marble Machine

Posted on by

Prolific creator [Martin Raynsford] recently created a plus-sized edible version of his laser-cut Marble Machine for a Cake International exhibit and competition; it seemed simple to do at first but had quite a few gotchas waiting, and required some clever problem-solving.

The original idea was to assemble laser-cut gingerbread parts to make the machine. Gingerbread can be laser-cut quite well, and at first all seemed to be going perfectly well for [Martin]. However, after a few days the gingerbread was sagging badly. Fiddling with the recipe and the baking was to no avail, and it was clear [Martin] needed to …read more

Continue reading Problems that Plagued an Edible Marble Machine→

DIY Capacitive Rotational Encoder on the Cheap with FR4

Posted on by

Rotary encoders are critical to many applications, even at the hobbyist level. While considering his own rotary encoding needs for upcoming projects, it occurred to [Jan Mrázek] to try making his own DIY capacitive rotary encoder. If successful, such an encoder could be cheap and very fast; it could also in part be made directly on a PCB.

The encoder design [Jan] settled on was to make a simple adjustable plate capacitor using PCB elements with transparent tape as the dielectric material. This was used as the timing element for a 555 timer in astable mode. A 555 in this …read more

Continue reading DIY Capacitive Rotational Encoder on the Cheap with FR4→

Snail is Actually Cleverly Strange Geocaching Waypoint

Posted on by

Basic geocaching consists of following GPS coordinates to a location, then finding a container which is concealed somewhere nearby. Like any activity, people tend to add their own twists to keep things interesting. [Jangeox] recently posted a video of the OLED Snail 2.0 to show off his most recent work. (This is a refinement of an earlier version, which he describes in a blog post.)

[Jangeox] spices up geocaching by creating electronic waypoints, and the OLED Snail is one of these. Instead of GPS coordinates sending someone directly to a goal, a person instead finds a waypoint that reveals another …read more

Continue reading Snail is Actually Cleverly Strange Geocaching Waypoint→

Stop Motion with the Time Glove

Posted on by

What do you get when you put an ultra-bright LED in the palm of a glove, and strobe it controlled by an accelerometer? A Time Control Glove! In creator [MadGyver]’s own words, it’s “just a stroboscope with frequency adjustment” but the effect is where all the fun is.

The Time Control Glove uses the stroboscopic effect, which many of us have seen used in timeless water drop fountains where the strobe rate makes drops appear to change speed, freeze in place, and even change direction. [MadGyver] made the entire assembly portable by putting it into a glove. An on-board accelerometer …read more

Continue reading Stop Motion with the Time Glove→

Star Wars Speeder’s Finishing Touch: Mirrors

Posted on by

[Super 73] make electric scooters, and they made some Star Wars Speeder Bikes with a twist for Halloween; adding some mirrored panels around the bottoms of the bikes made for a decent visual effect that requires no upkeep or fancy workings. Having amazed everyone with the bikes, they followed them up with a video of the build process.

The speeders are shells built around their Super 73 electric scooter, with bases of what looks like MDF sitting on anchor points. Onto the base platforms goes cardboard and expanding foam to create the correct shapes, which are then sanded then coated …read more

Continue reading Star Wars Speeder’s Finishing Touch: Mirrors→