Open-source metal 3-D printer: This paper reports on the development of a <$2000 open-source metal 3-D printer. The metal 3-D printer is controlled with an open-source micro-controller and is a combination of a low-cost commercial gas-metal arc welder and a derivative of the Rostock, a deltabot RepRap. The bill of materials, electrical and mechanical design […]
Author Archives: DP
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 December 13, 2013
Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon. Bus Pirate Demo board free PCB build Using Bus Pirate to program I2C RTC Sick of Beige basic case v1 (DP6037) back in stock Coming up: Free PCBs via Facebook on Friday App notes on the weekend Free […]
No-connector AVR programming
Steve writes: Here’s a handy trick I developed while searching for ways to reduce the cost and assembly time of Floppy Emu boards. The board has space for a 3 x 2 shrouded IDC header, where the AVR ISP cable should connect. But that connection is only needed once, the first time the AVR is […]
AVR USB RGB LED controller
Zak Kemble writes: While working on an update for my CPU Usage LEDs project, I thought why not just make it into a universal RGB LED controller? The CPU Usage LEDs controller took a value between 0 and 255, worked out what colour it should be and then fade to that colour. This was very […]
Crystal oscillator frequency pulling
KF5OBS writes: This video briefly explains how to influence a crystal oscillator’s frequency by introducing reactive elements such as trim capacitors and inductors. This example uses a very simplistic Pierce oscillator and a crystal ins series resonance.
Bus Pirate Demo board free PCB build
Andrew Rohne blogged about his free Bus Pirate Demo board build: After building my first PCB a while back and starting to attempt to use it, I decided that the smart thing to do would be to finish build #2, which is a Bus Pirate Demo Board. This demo board has a handful of chips that can […]
Using Bus Pirate to program I2C RTC
@FrozenElecBlog tweeted, “Just published a video about the Bus Pirate — love this thing!!!”
VFD clock with SNMP and NTP
VFD clock with SNMP and NTP by Pyrofer: It sets itself via NTP and adjusts for daylight savings time so no buttons and it never needs adjusting. It can be monitored via SNMP for logging the temperature and checking system uptime. The entire SNTP stack was written from scratch and it all fits in one […]
A stand-alone access control with RFID
Boris of Open Electronics wrote an article on his stand-alone access control with RFID project: RFID Tags are increasingly used for many applications such as identifying objects by means of a code or access control. In logistics RFIDs allows asset tracking, or monitoring conveyor belts; in shops tags are often used as anti theft. RFIDs are […]
Open hardware pogo-pin programmer
Ethan Zonca of Protofusion writes: The PogoProg is a small open source hardware pogo pin programming solution. The PogoProg does not need a physical connector on the board, it uses surface-mount pads for signals and thru-holes for alignment. Two standard footprints are available, the smallest of which takes up very little space–only 7.6mm x 1.2mm! […]
#FreePCB via Twitter to 2 random RTs
Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week: Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch […]
Mains frequency display
fowkc has just published his latest project the mains frequency display: I wanted to make a display that could show the mains frequency to 3 decimal places. I’d be using the same seven-segment display modules that I used in my UNIX clock, so all I had to do was design the part that would work out the […]
Open hardware USB to RS485 adapter
Ethan Zonca of Protofusion writes: While developing the Luma RS485-networked LED driver we discovered a need for a small and inexpensive USB to RS485 adapter. We designed an adapter with a FTDI basic UART chip (FT230XS) and an inexpensive TI differential receiver (SN75176). Our small selection of parts brings the cost down to just over […]
Reviewing Dorji’s DSTH01 digital temperature and humidity sensor module
Raj did a review of Dorji’s DSTH01 digital temperature and humidity sensor module: The DSTH01 module is smaller than 0.4″X0.4″ in dimension and operates at 2.1-3.6V power supply. The pull-up resistors for I2C lines are available on board. I tested this sensor module with Crowduino (an Arduino Duemilanove clone with Atmega328) using Jonas Bo Jalling’s Si7005 Arduino […]
Kevin’s LED tester
Kevin Rye designed a simple LED tester: I decide to put together a small LED Tester board. It’ll be powered by a small coin cell battery. I can pick up an LED with a pair of tweezers and just simply tap it to the solder pads. If it lights up, I know I’m holding it […]
Voltage reference project
SUF shared his voltage reference project in the forum: To achieve the things above I designed a small battery good indicator circuit with a zener an opamp two LEDs and a few resistors. If you switch it on and the battery fall below 8V the red LED will lit instead of the green. I wanted to […]
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: EMC design considerations
Ever wonder why your project acts funny and sometimes causes unexpected outcome then one of these reasons are interference and how they inject into or emit from your designs. Learn more about EMC from Atmel’s design consideration notes. The electromagnetic environment is getting tougher. High-frequency radio transmitters, like mobile telephones, are found everywhere. More and […]
App note: EMI noise protection on electronic equipment
This application manual from Murata packs a lot of information about noises generated from most electronics equipment and what are the right filters to suppress these. To make effective noise suppression in electronic equipment it is necessary for design engineers to have a good understanding of the various types of EMI suppression filters available and […]