The ATX breakout board bench power supply is back in stock at Seeed Studio. This board recycles an old computer PSU into a handy bench tool with 3.3/5/12/-12 volt supplies. You can get one for $14 at Seeed Studio. You can also get a Sick of Beige case for your ATX breakout board for $4 […]
Author Archives: DP
ESP8266 breadboard adapter board
Markus designed a single-sided ESP-12/ ESP-07 breadboard adapter PCB: Features are: – Fits ESP-12 and ESP-07 module – Single-sided self-etchable design – Few, cheap parts in SMD – Breadboard-style – one row on each side accessible – Vin >4.5V (max. 7V) input possible with 3V3 onboard voltage regulator (with two capacitors 10µF) – Power-indicator LED […]
Mullard 3-3 Amplifier project (part 2)
Dilshan Jayakody writes: This is a second article related to Mullard 3-3 Amplifier Project and in this article we introduce HT transformer and HT power supply related to this amplifier. As mentioned in previous post, power supply unit of this tube amplifier is constructed using 400V 5A bridge rectifier, 220µF (400V) and 82µF (400V) electrolytic […]
555 timer teardown: Inside the world’s most popular IC
Another great teardown article by Ken Shirriff, a look inside the 555 timer chip: Given the popularity of the 555 timer, I thought it would be interesting to find out what’s inside the 555 timer and how it works. While the 555 timer is usually sold as a black plastic IC, it is also available […]
App note: Voltage generating circuits for LCD contrast control
Another application note from Hantronix, Inc. on simple to digitally controlled efficient power supply for LCD display contrast. Link here (PDF) Many LCD display modules require a negative or positive voltage that is higher than the logic voltage used to power an LCD. This voltage, called Vl, Vee or the bias voltage, would require a […]
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: An explanation of LCD viewing angle
An application note from Hantronix, Inc. on LCD viewing angles and how it influences the selection of the right LCD for your application. Link here (PDF) LCD displays have a limited viewing angle. They lose contrast and become hard to read at some viewing angles and they have more contrast and are easier to read […]
App note: Designing with the EZ-USB FX3 Slave FIFO Interface
Designing with the EZ-USB FX3 Slave FIFO Interface application note (PDF!) from Cypress: AN65974 describes the synchronous Slave FIFO interface of EZ-USB FX3. The hardware interface and configuration settings for the FLAGs are described in detail with examples. The application note includes references to GPIF™ II Designer to make the Slave FIFO interface easy to […]
App note: MMCM and PLL dynamic reconfiguration
Xilinx application note (PDF!) on MMCM and PLL dynamic reconfiguration: This application note describes the information necessary to reconfigure the MMCM or PLL and provides a reference design that implements all of the algorithms covered. The PLL and MMCM share very similar functionality but are not identical. Due to some subtle functionality differences and the requirement […]
An S/PDIF sound card using the PCM2906
Joesugar writes: When S/PDIF became available in the Teensy Audio Library I thought this might be the solution to ground loop problems I’d been having when interfacing projects to my PC. However, I quickly realized I didn’t have any sound cards with an S/PDIF interface. In the belief that I’d rather build than buy I decided […]
OpenDrop – Digital Microfludics Plattform
An open source digital microfludics platform from GaudiLabs, that is available on github: OpenDrop is a new design for an open source digital microfludics platform for research purposes. The device uses recent electro-wetting technology to control small droplets of liquids. Potential applications are lab on a chip devices for automating processes of digital biology. How […]
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. The coupon code usually go to Facebook ‘Other’ Messages Folder . More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three […]
PWM dimmer for LED lighting
Lukas Fassler has published a new build, a DIY PWM dimmer for LED lighting: I have recently moved to a new apartment and was looking for a PWM dimmer to control some 12V LED strips. I thought that should be easy enough nowadays but it proved more difficult than I thought. All I found either didn’t meet […]
Quantifying cooling
Chris Palmer (a.k.a nophead) has designed and built this coolometer project to quantify the cooling effectiveness of various fan: I was wondering about how I was going to calibrate the airflow reading but then realised that the flow rate is not actually what I am interested in. It is the cooling effect the airflow has, which is […]
Programmable CW Morse Keyer / beacon
Marko Pavlin has designed a Mini USB dongle with STM32F0xx , he writes: Mini USB dongle with STM32F0xx is suitable many for simple, mini projects. I attached speaker to Timer14 PWM output (Pin PA6) and LED (or optocoupler connected to PTT) to GPIO pin PA0 The provided software is based on USB Virtual Com Port (VCP) device. […]
#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 […]
Inside the arm1v – the ALU control logic
Dave writes: This is one of a number of posts on my work on reverse engineering the armv1 processor. The first in the series, and an index of the other articles can be found here. My first post in this series described in some detail a one-bit slice of the ALU, and identified quite a […]
DIY synth building, part 2
Here’s a video tutorial on making a sequencer circuits from Casper Electronics: Learn how to make a variety of musical pattern sequencers using a few common electrical components and a breadboard. See the part 1 video on building oscillators here.
Nixie thermometer
Luca Dentella has developed a Nixie thermometer to measure the temperature of the liquid cooling system, that is available on Github. I decided to log the design and the development of the project in ten blog posts. They show my “divide et impera” approach: I divided the whole project in small tasks (drive a nixie […]
App note: High-speed input clock issues
Clock jitter are a big issue in high-speed ADC, here’s an application note from e2V to guide users deals with these problems. Link here (PDF) The e2v converters family addresses the high-speed market in the field of ADCs as well as DACs, with frequencies operating in the GHz range. Such high-speed devices require high-speed clock […]