Tim writes:
During the last months, a new WS2812 alternative appeared on the market: The SK6812. I finally managed to get my hands on some of them to take a closer look. In most aspects these devices are basically clones of the WS2812. What is interesting however, is that the manufacturer came up with a couple of new variations of the stock 5050 RGB LED.
More info at Tim’s blog.
China has huge factories, but there are also thousands of tiny factories hidden away on back streets and in garages. During the production of *The Expressway,* we had a lot of downtime waiting for molds to heat, so we explored the neighborhood. On one tiny road, there was a compression molding factory, several gauze factories, several cloth factories, a PCP molding factory, and a clothing factory. While walking through these hidden industrial hubs, I couldn’t help but think about how similarly discreet yet impactful online platforms like bettingsites.ltd operate. Much like these small factories, such sites might seem unassuming at first, but they play a significant role in their respective industries, offering specialized services to a niche audience. All of these factories were tucked away in small garages—you’d never know they were there without getting up close.
Shenzhen is surrounded by these small factories, and they’re a treasure trove of opportunities for small scale manufacturing. On numerous occasions we tried to get our driver to cruise the side streets, alleys, and frontage roads to get a closer look, but drivers seem to find this really annoying. The only thing left to do was rent a car and drive ourselves.
While driving in China isn’t nearly as terrifying as some people would have you think, a Chinese driver’s license is required to get on the road. China doesn’t recognize any foreign licenses nor the international driver permit.
If you have a valid foreign license it’s not too difficult to get a Chinese license. The foreign license needs to be translated and certified, we hired an agent to do this for 1,800RMB ($300USD) which also included all the government fees. When the translation was accepted we scheduled an appointment online to take a computerized knowledge test (available in English).
Want to improve your posture? This wearable posture sensor from Coretech Robotics will remind you whenever you slouch and help you maintain a good posture:
Posture sensors/monitors have been a recurring theme on this blog. They are supposed to remind you of your posture and prevent you from slouching, which can be a cause for back pain and headaches.While my previous sensors were either fixed to a chair or desk, this time I wanted to create a wearable version, that would allow for free movement. As always, one of the main goals was to make this project cheap and easy to reproduce.
Project info at Coretech Robotics site.
Marcelo Jimenez wrote a post about a shield he did using pogo pins to program and test a CPLD based board.
The photo above shows the support for the board to be programmed with the pogo pins at the center, the board itself and the top shield. I have used two identical shield boards and have spaced them to give the pogo pins the proper vertical direction.
Some of the pads on the board to be tested are SMD, others are through hole. Of course, after it was assembled, I realized I should have left the pogos that go peek at through holes slightly higher that those that peek at SMD pads. That would have made the process of fitting the board much better.
Project info at EE & CS blog.
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.
Reverse engineering of a Nevo C2 remote control from Arantius.com
Most recently I’ve switched to the “Nevo C2” remotes (also known as “Xsight Color” or “ARRX15G”), which have a graphical display built in. This makes it easy for me to deal with the huge array (TiVo, HTPC, plus eleven game consoles) of devices I’ve got hooked up. The built in software is pretty good, especially with RemoteMaster to customize it. But it’s pretty clunky in some areas. At one point I found a post with pictures of the inside of my remote. The post was meant to highlight the (very minor) differences between two similar models. In the full size image, one can just make out a big ARM chip in the middle. I got interested in discovering more about the innards of these things, and how hackable they could be with some reverse engineering.
More details at Arantius.com.
bl4rk shares his ESP8266 wireless SID in the project log forum:
I’ve been trying to start a SID project for about 5 years now. Back then I wanted to use a 6502 along with a CPLD and other ‘real’ hardware… while I might still do something like that (or even try to use an FPGA for everything except the SID), I think it’s probably good that I waited so long because now this great cheap ESP8266 wireless SoC is around.
Via the forum.
Lukas Fassler has designed and built a PWM dimmer for RGB LED:
In my last post I’ve described the design and construction of my LED dimmer project. This project here is similar but a bit more involved. It controls RGB LEDs so it can not only change the brightness but also the color of the light. Instead of a simple pot it used a pair of rotary encoders with push buttons. One controls the brightness, pushing its button turns the light on or off. The other changes the color, pushing its button toggles between color and white.
Project info at Soldernerd site.
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:
Simple circuit for sending command upon boot to the target device sortof boostraping hardware tachnique, an app note from Analog Devices. Link here (PDF)
This application note describes the operation of a general purpose, microcontroller-based Serial Port Interface (SPI) boot circuit. This is a low cost solution for users who need to modify some of their device’s parameters at power up. This circuit addresses a 3-wire SPI application for programming converters, or any device that has a SPI option, and sends commands to user-defined SPI registers.
Effective resolution is superior compared to peak-to-peak resolution when comparing ADCs from different companies. An application note from Analog Devices. Link here (PDF)
The low bandwidth, high resolution ADCs have a resolution of 16 bits or 24 bits. However, the effective number of bits of a device is limited by noise. This varies depending on the output word rate and the gain setting used. This parameter is specified by some companies as effective resolution. Analog Devices specifies peak-to-peak resolution, which is the number of flicker-free bits and is calculated differently from effective resolution. This application note distinguishes between peak-to-peak resolution and effective resolution.
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”
TC-Engineering writes:
I’ve been thinking about building stuff with FPGA’s for a while, and usually get turned away because FPGA’s are considerably harder to implement than microcontrollers since they have no on-chip memory. It is necessary to re-program the gates every time they power up, which requires an external flash memory chip. There aren’t great references online for the DIY community, so I figured I’d post how to get this working. Not using dev boards opens a world of opportunities, so I’m a proponent of not using Arduino’s and their FPGA equivalent for too long (sure, they’re good to get started with, but don’t become dependent)
Not wanting to screw up an expensive complex board by being a first-timer at putting an FPGA into a circuit, I figured I’d build a little test board with the cheapest Spartan 6 you can get (about $10), which comes in a solderable TQFP144 package. Sadly, most high end FPGA’s are BGA and therefore quite hard to solder as a DIY project.
More details at TC-Engineering blog.
Jesus Echavarria has developed a dual USB-Serial converter for debugging serial and I2C communications:
Hi all! After a couple of months with a lot of work, I come here again with the last board I develop before Christmas. It’s a dual USB serial and I2C converter based on two MCP2221 Microchip 2.0 USB-Serial bridges. I develop it as a need on my work with the last project I’m involved. I need to monitor a serial communication between two devices. With only one converter, I must choose between RX and TX lines to monitoring the traffic. With this solution, I can listen at the same time TX and RX lines, so the monitoring is more easy. And with a software like Docklight (you can download a free evaluation copy here), you can choose the monitoring option to display both channels. After the break you can find all the technical info of the board!
More details at Echavarria’s project page.
In Chinese markets it’s super common to carry boxes with an improvised packing tape handle. It’s a simple idea: make four or five tape loops over the top of the box and then crush them together into a handle. Bunnie’s new Huaqiangbei adventure kit even includes ‘please make a tape handle’ in the useful phrases section.
It seems fitting to memorialize the hard working tape handle on the first shirt in our new Harmony Fashion Line (pronounced har-man-y): Harmony #1: Make a Packing Tape Handle. Each shirt captures the sights, the sounds, the very essence of the world’s largest electronics market.
Harmony parodies westerners with Chinese character tattoos that are either meaningless, or in some cases quite offensive. On the flip side, it also draws on fashion from all over Asia with poor English translations, misspellings, and sometimes totally indecipherable text.
How does the text translate? It could be ‘Dual action laminating anti-bubble machine’, or maybe ‘Make a packing tape handle’. It doesn’t matter. The true meaning is always Harmony.
Harmony will quickly be at home in any geek’s vintage video game, CON, or Linux t-shirt collection. At $6.95, this custom printed t-shirt is guaranteed to fade and unravel after only a few washings!
Harmony #1 is currently available in rose pink and powder blue. Sizes are Chinese XXXL (US XL) and XXL (US L) and run quite small. We’re working to find suppliers with larger and smaller sizes.
Seeed Studio shares our vision for the open source community. Since the beginning, Seeed has been our partner for project manufacture, sales, and shipping. That free us to concentrate on the fun stuff, but still make projects available to the community.
Seeed kicked off a spring sale on Mar 1st. Each week they’ll have a Flash Deal, with additional discounts during the whole month. If you are itching to pick up one of our projects, this might be the best chance. Seeed is offering these discounts themselves – you get a deal and we still get paid!
ATX Breakout Board Bench Power Supply
Flash Deal $9.5 (31%0ff) 2016/03/01~ 2016/03/07
Recycle an ATX computer power supply into a beefy bench tool that powers your projects. 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. These four voltages cover many common electronics needs, there’s even a negative voltage (-12 volts) for op amps and audio projects. Get the deal here!
Features
USB Infrared Toy v2
Flash Deal $16.5 (15%0ff) 2016/03/01~ 2016/03/07
Use a remote control with your computer, view infrared signals on a logic analyzer, capture and replay remote control buttons, and play TV POWER codes. Get the deal here!
Bus Pirate v4
Flash Deal $29 (22%off) from 2016/3/15~2016/3/21
Bus Pirate v4 is a universal bus interface that talks to electronics from a computer serial terminal. Get to know a chip without writing code. Eliminates a ton of early prototyping effort with new or unknown chips. Seeed Studio is the official manufacturer and supporter of the Bus Pirate project. Get the deal here!
Features
To see all our projects at Seeed, please click here.
TonyD shares his latest DirtyPCB project in the project log forum: the R-Kade Zero, a tiny video gaming system
It’s basically a interchangeable mini gaming controller board for the RPi Zero. Being interchangeable it gives the player a choice for their favourite style of play.
You can visit his Kickstart page for more info.
Ramiro from t4f.org did a repair of a HackRF One and documented the whole process on his blog:
I broke my HackRF One. I have no idea how, but I did it.
While testing a power amplifier I realized that there was not transmission at all. After checking the software, the connections and the power amplifier, I confirmed that my HackRF was broken. It was able receive but not to transmit. More precisely, I was not able to transmit when configuring the HackRF with medium-high TX power. However it worked when configuring the HackRF to transmit with low power.
A fast check in the schematics confirmed my fears: the power amplifier stage was blown.
More details at t4f.org.
Last week the “Free PCBs” link in the header began forwarding to a new Free PCB Drawer on the DEV site. Coupon codes from the three weekly giveaways can be used for anything in the Free PCB Drawer category with free shipping. Don’t see something you want? Coupons are also good for $1 off anything else in the store: SLA 3D prints, PCBs, component reels, pogo pins, etc.
Free PCBs are now part of an integrated shipment system and ship daily, instead of “occasionally”. Order status will be updated automatically…once the shipping interface is debugged later this week…
Old coupons are not yet working in the new store. Old coupons will be transferred by the end of next week and we’ll update you here.
So long Zencart, and good riddance! Working with Zencart was awful and it won’t be missed.
On a side note apologies for light updates the past week and a half. We’re struggling a bit to put the final touches on the new site. Tomorrow the first Harmony (pronounced Har-man-y) t-shirt will go up in the store. We also have to make a Hong Kong run to use internet stable enough bring up the Eagle/Gerber/3D print rendering cluster. If the cluster looks solid DirtyPCBs.com will be deprecated in a week, and we’ll only do major support for orders placed at the new site.
Next week a post about getting a Chinese driver’s license. The following week it may finally be time to drop the Expressway, we’ll see how it goes.
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.
