Microsoft “Intellimouse” teardown from Electronupdate:
Before the advent of optical mice, the go to technology was a steel ball which moved two drive shafts to indicate position.
A good example of this is this Microsoft “Intellimouse”.
As expected the electronics are built around a small micro controller
Check out the video after the break.
Steve Chamberlin has written an article about Raspberry Pi GPIO programming in C:
The Raspberry Pi’s 40-pin GPIO connector often gets overlooked. Typical Pi projects use the hardware as a very small desktop PC (RetroPie, Pi-hole, media center, print server, etc), and don’t make any use of general-purpose IO pins. That’s too bad, because with a little bit of work, the Raspberry Pi can make a powerful physical computing device for many applications.
More details at Big Mess o’ Wires homepage.
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 get a coupon code for the free PCB drawer tomorrow morning. Pick your own PCB. You get unlimited free PCBs now – finish one and we’ll send you another! Don’t forget there’s free PCBs three times every week:
Good read app note from Texas Instruments about configuring unused op amps on multi amp chips. Link here (PDF)
Multi-channel operational amplifiers (op amps) are often implemented in circuits that do not require the use of all channels. Undesired behavior in an unused amplifier channel can negatively impact system performance, as well as the performance of the channels in use. To avoid degradation of both the op amp and system performance, the unused op amp channels must be configured properly.
App note from Texas Instruments about output current sensing in class-D amplfiers. Link here (PDF)
Current sensing in audio subsystems are widely used in conjunction with CLASS-D amplifiers for diagnostics or to provide speaker current feedback to the DSP for speaker enhancement to emulate smartamp. The most expensive component in the audio subsystem is the speaker. The impedance of the speakers ranges from 2Ω for subwoofer to a 8Ω for stereo speakers. Exceeding the current flowing through the speakers has a potential to create excessive heat in the voice coil which can lead to permanent damage of the speakers.
From the comments on our ChipKIT based weather station using BME280 sensor module post, Edward Mallon writes:
A lot of us have ended up at this sensor / screen combination. But I couldn’t afford the extravagance of six dedicated control lines on our little pro mini based loggers.
However with some slight modification, you can drive the Nokia 5110 LCD with only 3 control lines, and power the display from a digital pin
More details thecavepearlproject.org.
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 times every week:
Continue reading “Free PCB coupon via Facebook to 2 random commenters”
Ken Shirriff has written an excellent in-depth look at the 76477 sound effects chip:
The 76477 Complex Sound Generation chip (1978) provided sound effects for Space Invaders1 and many other video games. It was also a popular hobbyist chip, easy to experiment with and available at Radio Shack. I reverse-engineered the chip from die photos and found some interesting digital circuitry inside. Perhaps the most interesting is a shift register based white noise generator, useful for drums, gunshots, explosions and other similar sound effects. The chip also uses a digital mixer to combine the chip’s different sound generators. An unusual feature of the chip is that it uses Integrated Injection Logic (I2L), a type of digital logic developed in the 1970s with the goal of high-density, high-speed chips. (I wrote about the chip’s analog circuitry last year in this article.)
See the full post on his blog here.
Dilshan Jayakody published a new build:
Couple of months back we decided to create our own media server to store our MP3s and digital photographs. But it gets postpone several months due to unavailability of main-boards and other resources. Finally, after reviewing several prototypes we decided to build our media server using Banana Pi (BPI) and MiniDLNA. Before finalize BPI we checked several main-boards which including Raspberry Pi B+, Orange Pi One and BeagleBone Black. Out of all above main-boards we choose BPI M1 because of its inbuilt SATA2.0 interface, Gigabit Ethernet port and availability in local market.
See the full post on his blog here.
Dave Richards (a.k.a. AA7EE) has a nice write-up about building another Si5351 VFO project:
To many, this will be just another Si5351 VFO project, with nothing to distinguish it from the others. In fact, that’s exactly what it is. The “how to” of connecting an Arduino board to an Si5351 board, wiring up a display, and loading the firmware, is straightforward, and well established. To me though, it was a complete mystery.
See the full post on his blog here.
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:
Some stuff:
We try to stagger free PCB posts so every time zone has a chance to participate, but the best way to see it first is to subscribe to the RSS feed, follow us on Twitter, or like us on Facebook.
Kerry Wong did a teardown of a cheap GM3120 field strength meter:
There are a lot of cheap electromagnetic radiation testers out there which boast some quite impressive claims. So I decided to pick up a popular one (GM3120) from eBay to see how well it works. And perhaps more importantly, I wanted to take a look inside to see how the E field and H field sensing is done.
Most professional field strength meters feature a dome-like sensor. Housed inside are three orthogonally arranged antennas used for picking up field component in that axis. A cheap tester like the GM3120 clearly doesn’t utilize this kind of sensor topology and presumably can only discern field strength along a single axis.
See the full post on his blog here.
Check out the video after the break. Continue reading “Teardown of a GM3120 electromagnetic radiation tester”
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 get a coupon code for the free PCB drawer tomorrow morning. Pick your own PCB. You get unlimited free PCBs now – finish one and we’ll send you another! Don’t forget there’s free PCBs three times every week:
App note from CREE on driving LEDs over its specified current capability. Link here (PDF)
The Applications Engineering team at Cree is often asked whether it is safe to operate Cree XLamp® LEDs with pulsed currents above the maximum data-sheet rating. This question is usually asked in the context of legitimate product requirements such as those posed by emergency-vehicle applications, specialized stroboscopic illumination and even pulsed modulation for general-illumination dimming applications.
The short answer is “it depends.” Multiple variables affect both initial and long-term performance and reliability of an LED. These include thermal resistance, pulse duration, as well as current amplitude, frequency and duty cycle.
Application note from CREE on efficiently designing a conventional FR4 PCB to manage thermal heat and as a cheap alternative to metal core pcbs. Link here (PDF)
One of the most critical design parameters for an LED illumination system is the system’s ability to draw heat away from the LED junction. High operating temperatures at the LED junction adversely affect the performance of LEDs, resulting in decreased light output and lifetime. To properly manage this heat, specific practices should be followed in the design, assembly and operation of LEDs in lighting applications.
Matt Brailsford (aka Circuitbeard) has a nice write-up about building his mini pinball machine with a lattepanda core running dual monitors:
I generally start my projects by thinking about the hardware that I’m going to want to use as I’ll need to know sizes when it comes to the design phase. My first thought was to go with a Rasberry Pi as it’s what I’m familiar with and it’s what I’ve used for my other arcades, but after looking online, there really didn’t seem to be any good options for pinball emulation on Linux at all. It all seemed to be windows based. Thankfully I remembered reading about a single board Windows computer called a LattePanda so I thought why not give that a go and so this was the approach I ended up taking.
Build log at Circuitbeard blog and the GitHub repository here.
Check out the video after the break. Continue reading “Rombus pinball – a LattePanda mini pinball machine”
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 times every week:
Continue reading “Free PCB coupon via Facebook to 2 random commenters”
CAPS0ff team posted an article taking a closer look at 8 “PIC16C57s”:
We were recently sent 8 “PIC16C57s” from:
*High Seas Havoc (403/C013)
*Wargods (U69, C020)
*MACE (U96, C021)
*Carnevil (U96, C022)
*BioFreaks (C023)
*Gauntlet Dark Legacy (C024)
*Gauntlet (U37, C025)
*Blitz 99 (U96, C026)
More details at CAPS0ff blog.
bdring posted an update on NickelBot project we covered previously:
The NickelBot is complete and it works great. The goal of the project was to create an easily portable machine that creates low cost items that could be given away at events like Maker Faires. I think it has completely achieved that goal. The nickels are purchased from Amazon and cost about $0.08 each.
Project info at Buildlog.Net blog.
Check out the video after the break. Continue reading “Nickelbot – wooden nickel laser engraver”
Makervilla is back! It will be held on August 13th, 14th, 15th and 16th at Batam, Indonesia.
MAKERVILLA 2.0 is a 4-day creative learning retreat designed for local and international maker educators to gather under one roof for a time of learning, dreaming, hacking and sharing of ideas.
MAKERVILLA 2.0 is specially organized to address the needs of educators who are involved with maker education. Whether it is the need for peer support or understanding how to develop curriculum ideas, MAKERVILLA 2.0 will be able to facilitate the formation of learning network, professional learning community and special interest groups.
MAKERVILLA 2.0 is organized by Onemaker Group Singapore in collaboration with Ruang Kreasi Indonesia.
Find out more on their website at makervilla.com.
Mark your calendar!
