This video above demonstrates the speed difference between serial enabled/disabled on an Arduino Uno while toggling a pin output. Just a really simple test of how fast it can pull a pin high and low (without using direct port manipulation), with and with out serial enabled. I think that was the smallest Arduino sketch I ever wrote..
So I picked up a new good habit, ordering PCB boards. I know it might sound odd, but it really has become a habit. It started with an iPad charger I made, and now it is much more, and often.
It’s quite a simple process, dream up some neat little board, design it in Eagle, and order it via DorkbotPDX. There are even .dru and .cam jobs for you to use with Eagle, or you can just send the Eagle .brd file if you’d like. About 2 weeks later, you get 3 copies of what you ordered. It’s a fantastic way to get a few PCB’s made to test before ordering a big quantity, or just get a few for a personal project. It only cost $5 per square inch, with no setup fees and free shipping! It’s a great way to get boards made for the first time without the fear of losing a large amount of money involved with minimum quantities or setup fees. I have placed 7 orders and all have been perfect. So what are you waiting for? Give it a go! You can find all of the info on the DorkbotPDX PCB Order page.
For larger boards (150 square inches or more), or 4 layer boards ($10 per square inch), there is also a service. Details on the DorkbotPDX PCB Order page.
Below are some pictures of the boards I have ordered. Click for full res images. Continue reading →
I had a post a while back on charging an iDevice (iPhone, iPad, iPod) and talked about and showed a schematic for the charging circuit. This design is based (and the schematic is almost exact!) off of Ladyada’s Reverse engineering Apple’s secret charging methods. (video link, it’s good, you should watch it!) I give her full credit for the circuit. Now, the boards I whipped up in a few hours, and had it made from DorkbotPDX service. I sent off the files and 2 weeks later, I got three perfect purple PCB’s. The boards cost a total of $4.69. Shipped. You can’t beat that with a stick! Now, I have a nice little iDevice charger that accepts standard 5 volt power from any standard power supply. Although I do tend to favor 5V 2A supplies from Adafruit.
I used the same circuit I had in the old post, just added an LED and resistor for a power indicator. I had an old cell phone from 2006, and saved the keypad because it lit up blue. (Can you blame me?) Now, 6 years later those tiny 603 blue LED’s come in handy. I got the 603 resistor from an old PC motherboard. Motherboards have a slew of SMD things on them. So I fired up the hot air rework station, grabbed my tweezers, and voila! SMD parts! (I did order some reels of 603 resistors and LED for use in future kits, sorry peeps, no old motherboard parts for you!) I use a good pair of tweezers, and a viewfinder from an old camcorder to inspect my work. “But Jeremy? Where do you keep all of those SMD parts?” you ask? Good question, I use these awesome Modular Snap SMD component storage boxes from Adafruit. They have spring loaded tops, and they are modular, you can form them in any configuration you want! How cool is that?!
Adafruit now carries Solar Badges! It’s like free outdoor 5V batteries forever! I picked up a few of these and have been toying around what I’m going to do with them. They pump out 5V at 40mA for all of your portable power needs. The other huge plus about these is that the cell is a 2″ round badge that comes with a pin. This makes your power supply wearable to show the world your project! As described in the video above, this badge measures temperature, displays a color scale from red to blue, and flashes digits, displayed as numbered pulses for the temperature. It also has a RGB ‘rainbow’ mode for bling as well as constant color changing temperature display. It was a fun little project and you can pick up the Solar Badge, Perma-Proto Boards, TMP36 Temp Sensor, Tilt Switch, Push Button, RGB LED, and even the ATmega328 at Adafruit. Continue reading →