Embedded-Lab has launched a tutorial on interfacing a DC motor with a PIC microcontroller. It describes about the various operating modes of a dc motor and how to control them with a microcontroller. The tutorial also describes a classical H-bridge circuit using transistors.
Tutorial: DC motor interfacing to Microcontrollers - [Link]
This article shows how to convert a servo into and geared motor.
But, you still want the RPMs of a servo without the hassle of the pulsing control. So, you hack the servo and make it a geared motor. Easy! Here’s how…
Turn a Servo Into an Inexpensive Geared Motor – [Link]
This project is a LED reading lamp using SMD Leds.
At night, when I read in bed and my wife is trying to sleep, the lamp on the night stand is kinda bright and obnoxious and, even though she says it doesn’t, the light disturbs her. I had been using a little USB-powered LED lamp that I bought for my laptop on long night time airplane rides. However, I can’t charge my iPhone while I’m using that light. Only one USB cable available at the night stand. Also, that light isn’t quite bright enough for my liking. What to do?
LED Reading Lamp – [Link]
This project is an easy audio amplifier based on 8 pin DIP LM386 integrated circuit.
The potentiometer is the volume control. The heatsink is screwed to an LM7812 12V voltage regulator. There are a couple of caps and a diode on there. The wire with what looks like gum on the end of it is actually the headphones jack wire with a three-pin header molded onto the end using that really cool putty “as seen on TV” that you knead together and it forms really hard parts. I used it to protect the super-thin wires of the headphones jack. The little chip on that board is the LM386. The red- and black-tipped wires coming into the top of the breadboard just left of the diode and the voltage regulator are the leads from a Radio Shack 12V, 500 mA wall wart.
LM386 Easy Amp – [Link]
This project is a LED mood lamp using SMD RGB leds mounted on a dodecahedral assembly of custom circuit boards. In that way the light pattern is even. [via]
The first thing I did was devise a plane for the “bulb.” I decided to go with a dodecagon, which I believe means a 12-sided object. Actually, I had no idea what one of these things was called. I just figured that I needed pentagons to make something more globe-like than a cube. I wanted light to emanate outward from this bulb thing like a light bulb, but with as few sides as possible. The sides were no doubt going to be PCBs, so the less complex, the better. Not that this wasn’t one of the most complex circuit boards I’ve ever built in my short time as a hobbyist circuit builder.
A potentiometer controls the dimming of the LEDs. The other knob on the breadboard is a rotary encoder. This allows the user to change the mode of the lamp from a plain white for reading to an auto-cycling rainbow of colors to a user-selectable color. The built-in pushbutton changes the mode. The rotary encoder’s knob changes the speed of the auto-cycling colors or the user-selected color.
LED mood lamp – [Link]
Are you ready to wake up from the cult of Arduino? Tired of plugging together black-box pre-built modules like a mindless drone, copying and pasting in code you found on Hackaday? You’ve soldered together your TV-Be-Gone, built your fifth Minty Boost, and your bench is awash with discarded Adafruit packaging and Make magazines. It’s time to stop this passive consumption. It’s time to create something that is truly yours. It’s time, my friend, to design your first circuit board. And you’ll need a machine to print it.
Outsourcing printed circuit board (PCB) manufacture can be expensive and slow. You want your board now, for free. And designing PCB’s is hard. You’ll make mistakes, and some boards will be wasted. You can etch your own PCB’s at home but the process is fiddly, and notoriously difficult to perfect. What if you had a printer that could make PCB’s? A rapid prototyping machine for circuit boards.
In this talk I will present my progress towards an inexpensive PCB printer by reverse engineering Epson inkjet technology. And I’m not talking about the crappy print-and-bake method you might have seen on the internet. Come and learn about the miracle of microfluidics within the modern consumer inkjet printer, and how to push it to do new, exciting things. I’ll be describing some reverse engineering techniques, a bit of electronics circuit design and the potential for 3D microfabrication with inkjet technology.
A PCB will be printed and etched live, on stage, at 27C3! [via]
Printing circuit boards lecture - [Link]
Welding with a buzz-box (AC arc welder) is much easier if you don’t have to scratch-start the arc. A high-frequency start circuit puts a high voltage (AC) in series with the low-voltage high-current welder output. Then, when the welding electrode is brought near the work, the high voltage (HV) ionizes the air and creates a path for the low-voltage and high-current arc.
High-Frequency Start Box – [Link]
This is a robot called Walter 1.1 and on the photo above you see the “head” that is moving on X and Y axis. Check details on the link below.
Walter 1.1 robot – [Link]
This project shows how to take a pair of speakers and put them in two of the original iPods where the scroll wheels normally were.
iPod Speaker – [Link]
This project is a Low Ohm meter able to measure 0.001 up to 1.999 Ohm with a “Direct Resistance Readout in Ohms”.
You must use two separate batteries. One for the DMM and one to supply power to the LM317LZ. I recommend the LM317LZ, which is the 100 mA, T0-92 version of the normal LM317. But you can also use the LM317, in the T0-220 package, if you want. The trimpot must be set precisely to deliver 100.0 mA out to get truly accurate resistance measurements. So you need a very accurate Milli-Amp Meter to adjust this Correctly.
Low Ohm Meter – Measures 0.001 up to 1.999 Ohm – [Link]