Nearly completed travel, meals, and entertainment log for tax year 2012. Filed Iowa state sales tax for the free PCB store experiment. Paid federal and state 4th quarter estimated taxes. Super important hint: Federal tax payment with EFTPS.gov is free, but you need to do it a few days in advance. Also filed 2012 1099-MISC […]
Author Archives: DP
Web Platform scratch and dent on its way to recovery
Tom redeemed one of his 7400 competition coupons for a Web Platform from the scratch and dent category of our free PCB drawer. He was able to ping it successfully and get it recognized over USB, so it looks like the major IC’s are functioning as intended. Dangerous Prototypes recently organized a give away of some […]
{AVR|PIC} Stamp dev board is simple, fast, has lots of I/O and serial
Bertho is working on an {Avr|Pic} Stamp development board for his local hackerspace. These USB interface boards are based on the ATmega32A and PIC18F46K22 microcontrollers. Both boards use the MCP2200 USB-to-Serial IC to interact with computers over a USB virtual COM port. There are often things you want to test quickly when designing something. Most […]
HOW-TO: MYSQL database remote backup script
Thanks to amazing Linux server admin Alex, this site is extremely well backed up. Every hour we make a complete copy of the local harddrive, and then incrementally sync any new data to an offsite storage location. If all this fails, we want to preserve the most important part of the site – the databases […]
No video today due to holidays
Sorry but there won’t be a video today due to the holidays. We had a few relaxing days off during the past week, and the workload has backed up on us. Sorry about that! We’ll be back next week to talk about PCB boxes and pull apart some trinkets we gathered from the electronics markets. […]
FT311D now supports Android Open Accessory Mode 2.0
A few weeks ago we posted that the FT311D Android Open Accessory (AOA) ICs didn’t support AOA 2.0 devices. This has been rectified in the latest silicon revision (rev C.). The device required a change to enable connection to the latest revision of Android Open Accessory Mode, upgraded from 1.0 to 2.0 in November 2012. […]
Jeremy Blum’s CadSoft Eagle video tutorials
OpenEnergyMonitor tweeted: Get started with Eagle CAD PCB design with Jeremy Blum’s video tutorials on @element14 site www.jeremyblum.com Via Twitter.
SPICEing Op Amp Stability
Drone writes: Here is a nice little app-note that describes a quick test for op-amp stability using SPICE. (Actually the technique might be useful on the bench as well.) The approach involves applying a step directly to the op-amp input pin and observing the step response. The Author points out what to look for in […]
ATX Breakout board free PCB build
Cosminnci built an ATX Breakout board v1.0 free PCB. The ATX breakout board routes the -12, 3.3, 5 and 12 volt ATX outputs to screw terminals, each protected by a 1.25 amp resettable polyfuse. If you build a free PCB we’ll send you another one! Blog about it, post a picture on Flicker, whatever – […]
7-channel relay and inductive load sink driver ICs
Uwe tipped us to Texas Instruments’ low power 7-channel relay and inductive load sink driver ICs: TI offers two rather new low power 1,8V & 3.3V & 5V 7-channel relay and inductive load sink driver ICs: – ULN2003LV (Output/Switching Voltage max. 8V – e.g. for 5V relays) – ULN2003V12 (Output/Switching Voltage max. 16V – e.g. […]
PCB a Week 3: Double sided breakout boards
Mats continues his challenge of designing one PCB every week. In week 3 he came up with a double sided breakout board containing footprints for 24 ICs on a 5cmx5cm board. Via the forum.
Why right angle bends on a PCB are not so bad
We’ve heard it numerous times: avoid using right angle bends in PCB routing. Here’s an article from EDN magazine explaining why it’s not as bad as most people think. The article explains that the “bad” effects like increased capacitance and circuit noise only start to be a pain for designers where signal speeds are above […]
GcStar personal collections manager
A followup to the Component Organizer source code released post: Another good program for organizing things (not limited to components) is called GcStar It’s very customizable. You can add whatever fields and categories you want, pictures of the component, etc. Thanks Wefwef! Via the comments.
App Note: Practical guide to high-speed PCB layout
Here’s an article from Analog Devices going into the details of high-speed PCB layout design. While the article mainly focuses on analog electronics, lots of good tips can be picked up for digital designers as well. Intelligent circuit-board layout is important to successful op-amp circuit design, especially for high-speed circuits. A good schematic is 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: Combining peripherals to implement a high resolution PWM
Here’s an app note from Microchip describing how to use the configurable logic cell (CLC) and the numerically controlled oscillator (NCO) peripherals to generate a high resolution pulse-width modulation signal. These peripherals are relatively new to Microchip’s product line and can only be found on some PIC10F and PIC16F devices: By itself, the NCO peripheral […]
App Note: DACs vs digital potentiometers
Here is an article from Maxim describing the differences between DACs and digital potentiometers. The article explains the characteristics and advantages of each, giving you a better idea of what you may need for your project. This application note compares digital to analog converters (DACs) to digital potentiometers. Traditionally digital potentiometers were meant to replace […]
App Note: Nuts and bolts of delta-sigma analog to digital converters
Here’s is a video from Texas Instruments describing the inner workings of delta-sigma analog to digital converters. The DS ADC is broken down into it’s basic parts. The delta-sigma modulator and digital decimating filter are then discussed. Delta-sigma converters are ideal for converting signals over a wide range of frequencies from DC to several megahertz […]
Workshop Update for December 28th, 2012
We’ve installed a second, duplicate WordPress blog to try to sort our the comments posting problem. We also searched for and wrote up the app note posts for this weekend.
Logic Shrimp v2b free PCB build
Mikelelere built a free Logic Shrimp v2b PCB. This board uses a single 23LC1024 SRAM to capture data on 4 inputs. The current v1 uses four 23K256s with each recording a single channel. Aerial data lines (SD0 – SD3) are now bi-directional as well. If you build a free PCB we’ll send you another one! […]