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 […]
Author Archives: DP
The 1 bit = 6 dB rule of thumb, revisited
Steven writes: Almost ten years ago I wrote an entry about the “1 bit = 6 dB” rule of thumb. This rule states that for each bit you add to a signal, you add 6 dB of signal to noise ratio. The first derivation I gave then was focused on the noise, where the noise […]
BGA Reballing Practice Kit
@joegrand tweeted, “Practicing BGA reballing with the @dangerousproto BGA Reballing Practice Kit.” More resources and instructions available here. Get your own kit for $79 at Seeed.
#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 […]
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: Low-power battery temperature monitoring
Low current consumption temperature battery monitoring TMP303 from Texas Instruments. Link here (PDF) Charging a battery cannot be independent of temperature. In fact, most batteries specify a range of temperatures where charging is permitted. Charging outside these bounds risks damage, failure or worse. To prevent charging when the temperature is too hot or too cold, […]
App note: Stopping reverse current flow in standard hot swap applications
Application report from Texas Instruments about a simple circuit that blocks reverse currents. Link here (PDF) The proposed circuit uses an inexpensive operational amplifier to sense the condition of the output voltage exceeding the input voltage, and subsequently disable the hot swap controller, stopping the flow of reverse current (current flow from the output (load) […]
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 […]
GPS tracking with an MSP430F5510 over GPRS
Bluehash over at 43oh.com writes: I found a tiny gem while browsing Github for MSP430 projects. This one is a GPS tracker based on a MSP430F5510 with a GPRS cellular connection for reporting and command input. The GPS is a FGPMMOPA6H from GlobalTop and the GPRS module is a SIM900 from Simcom. The Github link has […]
The 2017 Hackaday Prize
Hackaday just launched the 2017 Hackaday Prize, “Build Something That Matters” Hackaday is calling for the curious, the creative, the determined. The Hackaday Prize is for creating for social change in order to transform the world. Using your hardware and programming knowledge on top of your scientific, design, and mechanical abilities, you will innovate to make […]
DIY programming adapters
Sjaak writes: Today came in a new batch of PCBs from DirtyPCB.com, of which one is a new revision of the BlackMagicProbe. This revision is almost the same except it has a polyfuse in its powersupply to the target, a dedicated voltage regulator instead of P-FET, its programming header on the 90 degree on the […]
#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 […]
Practical RF filter design
Craig writes, “RF filter design is a piece of cake these days thanks to computer design and simulation tools. But actually realizing the simulated filter response in the real world can be a completely different matter! This video provides an introduction to practical RF filter design by building, testing, and tweaking a 137MHz bandpass filter […]
Inside the vintage 74181 ALU chip: how it works and why it’s so strange
Ken Shirriff writes: The 74181 ALU (arithmetic/logic unit) chip powered many of the minicomputers of the 1970s: it provided fast 4-bit arithmetic and logic functions, and could be combined to handle larger words, making it a key part of many CPUs. But if you look at the chip more closely, there are a few mysteries. […]
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: Fast Rail-to-Rail operational amplifiers ease design constraints in low voltage high speed systems
Migration to lower rail voltages considerations on operational amplifier designs an Application note from Analog Devices. Link here (PDF) Movement towards lower power supply voltages is driven by the demand that systems consume less and less power coupled with the desire to reduce the number of power supply voltages in the system. Lowering power supply […]
App note: Resolution enhancements of digital potentiometers with multiple devices
An old application note from Analog Devices about configuring multiple digital potentiometers to improve resolution, accuracy and programming complexity might add-up to the mix though. Link here (PDF) Digital potentiometers usually come with standard resistance values of 10k, 100k, and 1MW at a given number of adjustable steps. If an application requires a resistance range […]
USB Infrared Toy free PCB build
Ben Kazemi built a free USB IR Toy PCB. With the USB IR Toy you can use a remote control with your computer, view infrared signals on a logic analyzer, capture and replay remote control buttons. If you build a free PCB we’ll send you another one! Blog about it, post a picture on Flicker, […]
5V Regulator Cap for 9V battery
David Cook built a 5V regulator to sit atop a 9V battery: For quick portable projects and temporary hacks, it is often faster to reuse a simple 5V regulator circuit than to integrate a power supply into the device design. My toolbox has an LED tester and magnifier light, so why not add a convenient […]
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 […]