A member at Techshop had four motors and needed to use them to lift a heavy plate. He needed each motor to lift one corner; working in synch or else one corner of the plate would end up way to high.
The guy, a very talented woodworker & machinist, wanted a little help on the code. I wrote a simple Arduino program that implements a closed-loop position control algorithm. Because ultimately the mechanism was to be controlled with an Iphone / Bluetooth interface, I wrote it sort of like a “state machine”; implementing modes like “OFF”, “STOPPED”, “FORWARD”, “REVERSE”.
After a little debugging it actually works really good!
Detroit Metro Area is home to a huge pool of engineering & creative talent. Its probably got among the highest number of “makers of things” in all of the US. It also has great technical & art schools, and low rents.
There are a lot of people doing a lot of cool stuff.
I’ve visited the workspaces of some of these people, and belong to a couple myself.
I etched each tile with the laser, and arranged them to form the total image. The laser only removes the glaze, it’s still white. To give it color / contrast, I spray painted each tile & then quickly wiped it off using a paper towel (actually… many paper towels). The paint only sticks to the parts of the tile that were etched by the laser.
The laser settings are shown in a screen capture in the photo’s below, so is a shopping list in the form of a picture of my shopping cart. The total cost was about $120; a lot of which is the wood. The tiles themselves were quite cheap, I think 13 cents a piece from Home Depot.
Ever wanted to connect your electronics & Arduino to the web, via your home WiFi no less? Turns out it’s super easy with the WiFly chip by Roving Networks. I connected my Arduino Duemilanova to a network in a couple hours. It blows my mind how cool this is… connecting a 10$ micro controller to a wireless network?? That is really really sweet! I wanted this chip first for this home-automation project I’m working on, I didn’t do a lot of research ahead of time, but I was very pleasantly surprised with how easy it was to get it to work thanks to the great library & tutorials provided by the Arduino community.
Starting with this tutorial, I found a number of things that were out of date, and an ommision that is potentially DAMAGING to your chip. You need a voltage divider to convert the 5 volt pin’s of the Arduino to the 3.3V expected by the WiFly’s serial input.
Advice : 1) Do it, it’s totally cool
2) Read my updates to the tutorial below
2) Follow the tutorial, keeping the changes in mind
The build list is super short:
10K Ohm Resistor (2x), 20K Ohm Resistor (2x), 100 Ohm Resistor (3x), Arduino Duemilanova (1x, or similar), WiFly Chip (1x, from Sparkfun or similar, I used the RN-XV), generic LED’s (3x).
This already short build list could be further shortened; the status indicator circuit (100 Ohm Resisters & LED’s) isn’t really necessarily… as long as everything works the first time 😉 Also, the resistors used in the voltage divider (here 20K & 10K) could be altered so long as the ratio is between ~1.7:1 & ~2:1, and the values are in the 10’s of K Ohm’s.
I just got this to work with my Arduino Duemilanove & RN-XV using Arduino 1.0 IDE; however, it took some changes from the tutorial:
Updates to the tutorial, a couple notes:
1) In initSettings():
instead of: WyFly.SendCommand….
Make sure you’re editing your “Credentials.h” file in your example folder for the ssid & passphrase
“Time” the library, is no longer posted on the main Arduino library page, however it is still available here: http://www.arduino.cc/playground/uploads/Code/Time.zip
For pin’s 3 & 4 of my Arduino Duemilanove & RovingNetworks RN-XV I put a 10k Resister in series, then connected a 20k resister in parallel with the Tx&Rx pins of the WiFly chip & Ground (see schematic above). Before I did this, it would not connect to the network (probably because it was not communicating properly with the Arduino). This is a voltage divider circuit, it is **needed** because the chip’s datasheet clearly says you can only use up to a 3.3 V +- 10%, not the 5 V which pins 3 & 4 of the Arduino output.
After these changes, it’s working great! Wahoo! Thanks for the great tutorial & happy hacking
The two came together in this ridiculous Taco themed mural!
The skyline is Detroit as seen from Windsor ON, and the Taco pattern was based on a graphic I found online and then redrew to work with the 1/4″ router bit. I used Adobe Illustrator for the design and VCarve Pro 6.0 for the tool paths. I painted the 1/2″ MDF board with two coats of “Squash” yellow matte spray paint. I was very surprised at how even the color turned out, especially given how poorly it looked after the first round of paint. I cut the piece in one pass at 0.12 inches of depth, at a rate of 1.67 inches / second. Here’s a video of the cutting.