Author Archives: DP

#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 […]

Ceramic, tantalum, and electrolytic capacitor comparison

Arhi made use of his precision LCR meter to measure capacitance and ESR values of ceramic, tantalum, and electrolytic capacitors. He made his measurements at various frequencies to help him graph the changes to the values over a wide frequency range. From the graph it can be extrapolated that the ceramic capacitors have the lowest […]

Ultra-small vusbtiny AVR programmer

Philip wanted to make the smallest vusbtiny AVR programmer possible. His design incorporates both an edge PCB and a mini-B cable connector for the USB. Vusbtiny is a AVR programer based on the V-USB virtual low-speed USB firmware. V-USB is a software USB engine for AVR devices that don’t have hardware USB serial interface engines. […]

Sure Electronics PICkit 3 clone review

Sure Electronics starred carrying PICKIT 3 programmer/debugger clones. Chr bought one and wrote a in-depth review of this product. Rather annoyingly it didn’t work right out of the box, and the support staff was slow to respond. After hunting down an incorrect resistor value causing voltage reading problems Chr was able to repair the programmer.  […]

Portable software defined transceiver: VFO

Jason has been working on a portable software defined transceiver design for the past year. Every day this week he’ll discuss a different part of the hardware in a series of guest posts. You can chat with the designer in the forum.  Today’s post is about variable-frequency oscillators. The VFO is the heart of any […]

Soldering iron driver v2 build

Fcobcn received some soldering iron driver V2 PCBs from Arhi. He used replacement parts for those components he couldn’t find locally. The version 2 unfortunately only supports thermocouple type soldering pencils. Our recommendation is to use the V2 driver with ether the cheaper Solomon SR-976 pencil, or the more expensive Weller PES51. Support for PTC […]

App note: HV boost power supply for Nixie tubes

Here is a app note from Microchip describing how to implement a high-voltage boost DC-DC converter intended for Nixie tube designs. The basic principle of Nixie tubes is that they require more than 170V to function properly. This design uses the internal PWM generator of a PIC16 microcontroller to drive the DC-DC converter. A comparator […]

App note: Buck-boost converter

Here is an article from Texas Instruments featured on EETimes describing how to design a buck-boost converter. These converters are used when the input voltage can be both above and below the output voltage. One example are 3.3V systems powered by lithium-ion batteries which swing from ~3V to ~4V. This design is in effect a […]

App Note: Optimizing visibility and battery life of portable displays

Here is an app note from Maxim describing how to implement light intensity sensing in the visible spectrum. This is used to adjust the brightness of displays in portable devices. Human eyes only perceive a limited light spectrum. Sensors used to detect light intensity require complex conversions of their spectrum to emulate human eyes. Another […]

App note: Trouble shooting EZ-USB FX USB peripheral ICs

Here is an app note from Cypress with design guidelines for their EZ-USB FX1 and FX2LP USB peripheral ICs. They are basically 8051 microcontrollers with a built in USB serial interface engine. While these devices are easy to use, sometimes getting a new board up and running is tricky  due to the various details that […]

JuKu’s new Altium NanoBoard FPGA dev-board

JuKu got his hands on an Altium NanoBoard 3000. It’s a FPGA development board that goes with Altium Designer software. You get a choice of Xilinx, Altera, and Lattice FPGAs. One down side is that the license provided for the software expires in a year. This will be the basis of several projects I have […]

Custom PSoC3 development board updates

Kartik continues to develop his custom PSoC3 dev-board. In this update he was mainly concerned with adhering to USB guidelines. Another major change is the removal of a crystal oscillator. After checking out some Cypress development boards, Katrik noticed that most PSoC boards use an internal IC clock instead of crystals or oscillators. So he […]

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 a every week: Free PCB Sunday. The classic. Every week, […]

Week in (p)review: December 16, 2011

Here’s a summary of major developments over the last week: Bus Pirate week, day 1 – firmware development, day 2 – accessories and cables,  day 3 – cases and enclosures Bus Pirate firmware v6 test release a4 Bus Pirate servo driver documentation Application to Proto Labs for a Protomold Bus Pirate case We added documentation […]