This video by Steve of Big Mess o’ Wires demonstrates how to solder a 44-pin chip in a typical TQFP package using the drag soldering technique: The process begins by applying a liberal amount of flux to the pads, then positioning the chip on top. I use a pencil eraser to hold the chip steady while I tack down […]
Author Archives: DP
LEWE: the biometric wristband
Boris Landoni from Open Electronics writes about a new open source project the LEWE, a wristband that reads biometric: The Lewe project aims to collect and use available technologies to make a low cost idea that is applicable to all sectors using sensors for data collection. This project goal is the development of a communication protocol, […]
Use an LED as a sensor
Michael Beyhs shows us how to use an LED as a sensor: How the code works: Configure all analog inputs to outputs and pull low to turn on all red LEDs. Turn one analog input pin into an actual Input and read the amount of light that is reflected into it. Turn that input back into […]
#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 […]
Latest ‘New Year’ release of AnalysIR with full support for USB IR Toy
The AnalysIR crew has announced the the latest ‘New Year’ release of AnalysIR with full support for USB IR Toy: A major highlight of this release is full AnalysIR support for USB IR Toy from Dangerous Prototypes (V1 & V2 hardware) for decoding and resending IR signals at all common modulation frequencies. In our opinion, AnalysIR is now […]
NRF24L+ library for XC16
Arhi writes: I ported some NRF24l+ library long time ago but was having lot of problems with it trough time, it was not easy to use and had some conceptual problems that could only be solved by a complete rewrite so I looked around and found a very well written library for NRF24l+ made for […]
HP 6181C DC Current Source Teardown
Kerry Wong did a teardown of an old HP 6181C DC current source: HP 6181C is a lab grade 0 to 250 mA current source manufactured back in the late 70′s and early 80′s. There does not seem to be any pictures on the Internet for this particular model so I thought I would do a teardown […]
Testing switch mode voltage regulators
Bajdi did some tests for switch mode voltage regulators: There are different types of DC-DC regulators. The most common are linear and switch mode regulators. Everyone that has tinkered with electronics has probably used a 78xx series linear regulator. They are easy to use since they don’t need any special components. With most linear regulators you […]
A development board for Lua programming update
doub posted an update on his Lua board we covered previously: Today I soldered a second one, and it looks much better. Here is a picture. I just plugged it on my PC while pressing the DFU button and Windows recognized it as a “STM Device in DFU Mode”, and properly downloaded the drivers, so […]
Daisy chainable I2C splitter PCB
Tom shared his 1-3 I2C splitter he made in the project log forum: One of a series of modular expansion boards for the I2C bus: a 1-3 splitter for branching I2C signals. This is the first of a series of boards with compatible headers for modular expansion to the I2C bus. The boards all have the […]
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: PCB design for 10/100 switches and PHY
Design guide on PCB layout from Micrel on 10/100 switches and PHY This application note is intended to assist customers in designing products that comply with both EMI and ESD standards using Micrel’s 10/100 family of Ethernet products. The printed circuit board (PCB) is the single most important factor that affects EMI, ESD and overall […]
App note: Troubleshooting switching power supplies
Having problem with your switching power supply design? Or just curious on common switching power supply failures. Here’s a good resource from Micrel on troubleshooting power supplies. This application note provides insight on troubleshooting and taking measurements in switching power supplies. Specific measurements include output ripple, line and load regulation, efficiency, and transient response. Troubleshooting […]
electric imp-Controlled 120VAC relay switcher
Dillon Nichols blog about his electric imp-Controlled 120Vac relay switcher build: I bought an electric imp about a year and a half ago when they were released. I loved it’s simplicity and made a few temporary projects involving it but wanted to keep it for something more advanced. After all this time, I decided it’s […]
Vacuum fluorescent display alarm clock
Vacuum fluorescent display alarm clock by Andrew Rossignol: I have been working on this fun little project for the last couple of days. I ordered this VFD display from Noritake as a free sample. I am quite grateful for their generosity and I decided to put this display to good use. I have written a driver […]
Overclocking the STM32F4
mux writes: I’ve been doing some tests with the STM32F407 to see how fast it can go, STMicro has released an almost identical one that runs at 180MHz, is it a marketing thing ? will they release a 200MHz version in a few months? who cares, anyway, I was able to run the STM32F407 at […]
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 […]
Free PCB Store restock: Prototype Bus Pirate probe cables
Bus Pirate v3 probe cable (yellow and white) labels are available now in the free PCB drawer. A prototype probe cable for the Bus Pirate with male pins that fit in a breadboard. Each lead is labeled with a white or yellow printed shrink tube. Fits Bus Pirate v2go up to Bus Pirate v3.5.
Week in (p)review January 31, 2014
Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon. Free PCB Store restock: Heat shrink labels for Bus Pirate probe cable, and Dangerous Prototypes Stickers Programming a Silicon Labs’ EFM32 zero gecko with python via the Bus Pirate Using the Bus Blaster to program Lattice CPLDs Cristian’s 18F2550 […]
HP 3468A bench multimeter repair
HP 3468A bench multimeter repair: There are a number of great older bench meters out there that would be perfect when upgrading from a hand held meter when working on the bench. The HP 3468A meter can be had for under $200 in good working condition and often around $100 for a unit that powers […]