Paul over at Dorkbotpdx has written an article about his 7-segment countdown timer: The main challenge was driving the LEDs with a constant current, because they need about 10.5 volts across the several series LEDs. I wanted to run from 12 volts, so there wasn’t much voltage left over for the normal current limiting resistors. […]
Author Archives: DP
Soldering 8AWG wire with lead free
jwhitley89 tweeted: “And this is how you solder 8 AWG wire with lead free”
ATX Breakout Board V1.1 Acrylic case back in stock
The ATX Breakout Board v1.1 Sick of Beige case is back in stock at Seeed Studio. This case is designed to be simple, cheap, and easy to assemble. The ATX Breakout Board is sandwiched between two laser-cut acrylic sheets, and the whole assembly is held together with aluminum screws and standoffs. This is a minor […]
App note: Adding edge-sensitive transition detection to GPIO devices
Adding edge-sensitive transition detection to GPIO devices: Although many GPIO devices can detect the rising and falling edge of a signal-level change, some applications only need to capture the leading edge and not monitor the falling edge. These GPIO devices can be enhanced to detect edge-sensitive signal transitions. A simple circuit provides the transition detection.
Free PCB Sunday: Pick your PCB
We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service. This week two random commenters will […]
App note: Moisture tolerant QTouch design
“This application note describes the techniques to mitigate the issues caused by moisture in QTouch designs. (PDF!)” The basic conductive nature of water poses a great challenge to capacitive touch technology. This is aggravated by the varying salinity of water and the presence of impurities. Water accumulation can occur in a variety of unpredictable ways, […]
Decompensated operational amplifiers
“This video by Analog Devices’ Matt Duff explains why a few operational amplifiers (op amps) on the market are not stable at low gains, but are stable at higher gains.”
App note: Temperature sensor design guide
Temperature sensor design guide: In many systems, temperature control is fundamental. There are a number of passive and active temperature sensors that can be used to measure system temperature, including: thermocouple, resistive temperature detector, thermistor and silicon temperature sensors. These sensors provide temperature feedback to the system controller to make decisions such as, over-temperature shutdown, […]
PCB stencil service now available at Seeed Studio
Laser cut SMT stencil service is now available at Seeed Studio: After using rapid-prototyping tools such as Arduino and Grove to finish your prototype, you must desire to DIY PCB and PCBA to make your designs more concise. To make PCB manufacturing easier and more affordable, we’ve provided 2-layer Fusion PCB Service & 4-layer Fusion […]
Fixing a PM5132 function generator with the Part Ninja
JanW has used the Part Ninja to rescue a PM5132 function generator: Today I put the Part Ninja to good use, it came in handy when I was troubleshooting an old Philips PM5132 function generator. While I was working on a project I wanted to take a break and switched the signal gen off, later […]
Introduction to home automation
Introduction to home automation: We have all see some complex home automation systems, this video made by Jeremy from The Custom Geek gives a good overview of what is involved behind the scenes. This system lives in the garage and interfaces audio, video, phone, intercom, lighting and alarm system. Since the system is all connected […]
Free PCB coupon via Facebook to 2 random commenters
Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three times every week: Free PCB Sunday. The classic. Every week, get […]
Week in (p)review March 22, 2013
Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon. Logic Sniffer back in stock at Seeed Pre-China pilgrimage to Taco Loco Workshop Update for March 20th, 2013 Workshop Update for March 19th, 2013 Workshop Update for March 18th, 2013 Workshop Update for March 15th, 2013 Coming up: Free […]
Power charger and supply regulator
Asgard shared his BLiVIT project in the forum: One of the things I have noticed missing, for a pretty long time, is a good *safe* lithium cell charger that also supplies a load with a good efficient regulator. My answer, I hope is the BLiVIT. This is a moderate-sized board that incorporates charging from either […]
Auto-poweroff for an external USB hard drive
Hlipka has written an article about his auto-power-off project: I have an external hard drive connected to our satellite receiver for quite some time (to have it work as a PVR). But for some reason the disk won’t power down even with the receiver switched off (I verified – the disk itself is configured properly). […]
PK2DeviceFile.dat editing tool
AMX has written a command line tool to modify device files that are used by the pk2cmd tool: This gives a new device file named “pk2dev.dat”. I was able to dump and recompile the PK2DeviceFile.dat I am using and checked that the files are identical using “diff”. There are probably still some bugs but I […]
NAND gate computer
Kevtris presents this post explaining the process for designing and building this awesome NANDputer: What is a NANDputer? it’s a computer made out of nothing but NAND gates of course! I dunno why, but I thought it’d be fun to make this. I first had to work out how various parts of a CPU would […]
Project-a-week: RickPAW Betty crocker Arduino
This week Rwinscot shared his Betty crocker Arduino in the project log forum: I’d love to get into Arduino… but I don’t know how to solder. Which got me thinking about using through-hole sockets on a PCB. As the title of this post… a Betty Crocker Arduino. Add your through-hole components, mix, and bake your ideas. […]
Workshop Update for March 20th, 2013
We stopped by our Taco pilgrimage in Hong Kong, before heading crossing over to Shenzhen. In the workshop work continues on the Bus Pirate Edu Kit Documentation.
Solenoid control project
Doub shared his solenoid control project in the forum: I’m working on a solenoid control board, that would allow me to do sensorless position control (the algorithm is based on the varying inductance of the solenoid depending on the plunger position).