If you are looking to get started in AVR programming, I would be happy to recommend the kit from Adafruit. It’s easy to build, compact and most importantly appears to be very reliable and also compatible with the free software packages out there. It also includes an SPI interface which I have not tested yet.
The quality of the kit is very good, and the instructions supplied by Adafruit verge on the side of being too comprehensive. This makes it an ideal project for a stranger of the soldering iron.
No doubt you will be able to find commercially made programmers that visually look a little better, but what are you looking for here? You don’t head to a hardware shop and worry about the colour of a hammer that you are buying. The programmer is a tool, it will spend its life in your tool kit and the casing that it is contained within will keep the circuitry safe from knocks and short circuits.
The kit comes with both 10 pin wires and 6 pin IDC cables (A bonus) which should make it a flexible resource.
Here’s a video (m4v) about our new business cards, we’ll have these at Maker Faire this year! They’re laser cut “SPIROGRAPH” (hypotrochoid) cards, pop out the gears and you make your own designs!
What if there was some kind of apocalypse?” a friend fretted over dinner. “What if we had to survive in Stone Age conditions? Do we have any skills any more? What could any of us practically contribute to rebuilding civilisation?” A circuit of the table revealed that, indeed, almost all of us surround ourselves with products that we would not be able to make, repair or even properly explain.
But there is a new movement afoot designed to remedy this technical impotence. Just as the self-build trend is gathering pace, so too is a new wave in do-it-yourself (DIY) projects for the home – embracing everything from plumbing, woodcarving and pottery to robotics, electronics and recycling.
A documentary film by Jack Oatmon. A look into the hardware hacking community in Montreal, including the Foulab collective. Why are more and more hobbyists experimenting with hacks and circuit bends? What relationship does this imply about consumer society and technological advancement? Is this a real-world analog of ‘user generated content’?
n January 1975, Popular Electronics ran a cover story about a new computer for hobbyists. The Altair 8800 came as a kit and cost $439 (the equivalent of $1,778.58 in today’s dollars). It came with no on-board memory. You programmed it by entering Intel 8080 opcodes by hand via a series of switches on the front panel. Buying 4k of memory, the ability to read in programs from paper tape, and a teletype interface would increase the price 6 fold. You had to solder the thing together by hand. By comparison with the big university and corporate mainframes it was basically useless.
But Popular Electronics was the Make Magazine of its day and engineering schools had begun to require their graduates to learn some programming, so Forest Mims and Ed Roberts, the two guys in Albuquerque who’d put the Altair together, figured they could probably sell a few hundred in the first year to this emerging group of hackers avant la lettre…
First up, here’s our Drawdio Instructable! Next up – There’s a new Drawdio group on Instructables and your hack/mod/project could end up in a museum! Just add your Drawdio Instructable to the group, all submissions that have some original form factor (even superficial modifications count as original) will be included in the next Drawdio video and one entry will be chosen to be displayed in the Drawdio exhibit this Summer from July 25th to September 25th at “Freeze!–2009 International MedTech Art Show” at the Taiwan National Museum of Fine Arts. Another way to “enter” is to just come in person at Maker Faire and show Jay Silver your remix, which he will video tape on the spot. Jay (Drawdio inventor) will be at booth number “Expo 134″ (near the Exploratorium) at Maker Faire. And lastly, if you’re thinking about a Drawdio kit – here ya go!
High-school shop-class programs were widely dismantled in the 1990s as educators prepared students to become “knowledge workers.” The imperative of the last 20 years to round up every warm body and send it to college, then to the cubicle, was tied to a vision of the future in which we somehow take leave of material reality and glide about in a pure information economy. This has not come to pass. To begin with, such work often feels more enervating than gliding. More fundamentally, now as ever, somebody has to actually do things: fix our cars, unclog our toilets, build our houses.
When we praise people who do work that is straightforwardly useful, the praise often betrays an assumption that they had no other options. We idealize them as the salt of the earth and emphasize the sacrifice for others their work may entail. Such sacrifice does indeed occur — the hazards faced by a lineman restoring power during a storm come to mind. But what if such work answers as well to a basic human need of the one who does it? I take this to be the suggestion of Marge Piercy’s poem “To Be of Use,” which concludes with the lines “the pitcher longs for water to carry/and a person for work that is real.” Beneath our gratitude for the lineman may rest envy.
What is a photocell?
Photocells are sensors that allow you to detect light. They are small, inexpensive, low-power, easy to use and don’t wear out. For that reason they often appear in toys, gadgets and appliances. Theys are are often refered to a CdS cells (they are made of Cadmium-Sulfide), light-dependent resistors (LDR), and photoresistors.
Photocells are basically a resistor that changes its resistive value (in ohms Ω) depending on how much. They are very low cost, easy to get in many sizes and specifications, but are very innacurate. Each photocell sensor will act a little differently than the other, even if they are from the same batch. The variations can be really large, 50% or higher! For this reason, they shouldn’t be used to try to determine precise light levels in lux or millicandela. Instead, you can expect to only be able to determine basic light changes.
For most light-sentsitive applications like “is it light or dark out”, “is there something in front of the sensor (that would block light)”, “is there something interrupting a laser beam” (break-beam sensors), or “which of multiple sensors has the most light hitting it”, photocells can be a good choice!
Some basic stats
These stats are for the photocell in the Adafruit shop which is very much like the PDV-P8001. Nearly all photocells will have slightly different specifications, although they all pretty much work the same. If there’s a datasheet, you’ll want to refer to it
Size: Round, 5mm (0.2″) diameter. (Other photocells can get up to 11mm/0.4″ diameter!)
How to measure light using a photocell
As we’ve said, a photocell’s resistance changes as the face is exposed to more light. When its dark, the sensor looks like an large resistor up to 10MΩ, as the light level increases, the resistance goes down. This graph indicates approximately the resistance of the sensor at different light levels. Remember each photocell will be a little different so use this as a guide only!
No more USB cable, messing with power and timing values. Arduino + MotorShield + ScrewShield + train + hall effect sensor + two magnets = fairly precise stopping.
Want pretty Arduino sketches to include in your blog, just like us? Well, here is a little javascript fun! Use the Tools > Copy for Forum menu selection in the Arduino IDE to put the code into your computer clipboard. Then paste it in the form here – you’ll get nice HTML just posting code on the web, it will look like this…
int fsrAnalogPin = 0; // FSR is connected to analog 0
int LEDpin = 11; // connect Red LED to pin 11 (PWM pin)
int fsrReading; // the analog reading from the FSR resistor divider
void setup(void) {
Serial.begin(9600); // We'll send debugging information via the Serial monitor
pinMode(LEDpin, OUTPUT);
}
void loop(void) {
fsrReading = analogRead(fsrAnalogPin);
Serial.print("Analog reading = ");
Serial.println(fsrReading);
// LED gets brighter the harder you press
analogWrite(LEDpin, fsrReading);
delay(100);
}
Printable catalog (PDF) or (EPUB)
