Wingnut built an Equivalent Series Resistance meter based on this design. He made a couple mods to the original design to get better performance: I used a LMH6619 opamp for the oscillator, this is rail-to-rail output/input and 35mA current sourcing. This allows for a wider voltage swing and better drive capability compared to standard opamps. […]
Author Archives: DP
Bravia LCD TV teardown
Hak80r has been busy disemboweling electronic stuff lately. His latest is a cracked Bravia LCD TV. There’s lots of pictures, users with a slow connections be advised. Via the forum.
43oh winner: MSP430 iambic keyer
43oh, a forum dedicated to the MSP430 microcontroller, hosts a design contest. Last month we gave free PCB coupons to the winners. The winners also let us host their boards in the free PCB drawer. This board is an iambic keyer: On the heels of Rob’s Iambic Keyer comes N1KSN’s keyer. An iambic keyer is […]
REVIEW: Olimex PICkit3 programmer clone
A few weeks ago we wrote about a PICkit3 clone from Olimex available on eBay for $30. Compared to the original it is considerably smaller and at first glace it looks sturdier as well. We like that Olimex decided to use the large type-B connector which seems more reliable then the original mini-B. The ICSP […]
Turning your Flash Destroyer into a clock
Ok, so you burned all the memory chips you had around, and now a nice 7-digit display is standing on your desktop just taking up space. This hack turns your unused Flash Destroyer into a clock using a real time clock IC and some spare logic. Via the forum.
Simple USB to UART adapter that works with 3.3V and 5V UART signals
The serial UART is a common interface used by many chips and devices. Ginpb designed a USB-to-UART adapter that works with 3.3V and 5V UART signals. The device is based around the FTDI FT232BL USB-to-UART IC with an added 3.3V power supply. The different interface levels are selected by an on-board jumper. Via the forum.
App note: Detecting and locating RF bugs
We wrote about a phone bug in a previous post. Here’s an app note about a circuit for detecting and locating radio frequency transmitters. This design idea showcases a circuit that detects RF “bugs,” such as hidden wireless cameras, eavesdropping microphones, and other spying devices that emit RF frequencies in the 100MHz to 3000MHz range. […]
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 […]
48 ways to use a charge time measurement unit
The Charge Time Measurement Unit (CTMU) found on some PIC microcontrollers is a peripheral to interface with capacitive touch sensors. It can also be used in other functions, and the app note linked above provides a few ideas: In a nutshell, the CTMU is an on-chip constant-current source, surrounded by digital circuitry to precisely control […]
App note: dsPIC33E simultaneous analog sampling
Some new PIC 33E and 24E microcontrollers can take simultaneous samples from multiple analog to digital converters. Most chips measure analog values sequentially, but this ADC can sample 4 signals at once. Samples are still converted one after the other, but they’re collected at the same moment. More in the reference manual for dsPic33E and […]
4-Wire and 8-Wire resistive touch-screen controller using the MSP430
Resistive touch-screen films add more interface options to your projects. Here’s an app note from Texas Instruments on how to interface resistive touch-screens with MSP430 microcontrollers, but it’s good info for any chip: This application report describes how to use an MSP4309 microcontroller to drive and read a resistive touch screen. The hardware and software […]
High resolution capacitor meter
We’ve been researching various component testers, and BrentBXR tipped us about this high-resolution capacitor meter. It’s accuracy is claimed to be around 0.2%, which is much lower than typical capacitor tolerances. Internal comparators in a PIC16F628 create an oscillator with the capacitor under test. The oscillator frequency is proportional to the value of the capacitor. […]
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: January 06, 2012
Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon: Bus Pirate firmware v6.0 is now available for download Motherboard saved with the Bus Pirate and flashrom Boost converter shield for PIC programming with the Bus Pirate v4 Use Bus Pirate to upload Sketch to Arduino Ethernet CoolRunner-II […]
Hand soldering a BGA using the SchmartBoard|ez
Ball Grid Array chips have multiple rows of contacts under the chip. These are difficult to solder by hand, as we found out when Sjaak tried to solder a TMP006. Zeta tipped us to this video of hand soldering a 400 pin BGA chip to a SchmartBoard breakout. The breakout board has a via under […]
Telephone FM transmiter, AKA phone bug
If you ever wondered how those phone bugs from spy movies work, here is the schematic for your very own. This simple FM transmitter uses a phone line to both power the device and receive the audio signal. Just hook it up to the phone line you want to monitor and tune your FM radio […]
DIY clock based on 4000-series logic ICs
Terry built a LED bar display clock using only logic ICs: Although I’m way too late for the 7400 contest, I had built a chips-only digital clock from 4000-series IC’s The time was displayed by columns of LEDs i.e. first columnt was 1-12, and the led for that hour would be lit. The next column […]
PREVIEW: CPLD-based XT-IDE adapter V2
The second version of our CPLD-based XT-IDE adapter PCB is about to go to the board house. In this update all the logic ICs have been moved to the CPLD, making it fully programmable. The XT-IDE project is a Vintage Computer forum driven project to develop and manufacturer an 8-bit ISA IDE controller. It allows […]
AVR-based PIC programmer update
Fezoj made some updates to the user interface of his AVR-based PIC programmer. The project supports the PIC24F microcontrollers used in the Bus Pirate. There’s still lots of work to be done on this project, so if you’d like to contribute join the discussion in the forum.
WiFi-Jacket: Atmel-based MRF24 WiFi development board
Léon and a couple of his mates made a development board for the Microchip MRF24WB0MB/RM WiFi module. It’s based on the Atmel ATmega328 microcontroller and features lots of breakout pins, as well as some LEDs and buttons. Via the contact form.