Tiny ATtiny Node with temperature sensor project at Arduino Praxis:
Tiny sensor board with ATtiny84 and RFM12B Transceiver. The size of the PCB is 25 x 30mm, sightly larger than a canadian quarter coin.
$2 DIY compost thermometer build
afraser-kruck wrote this instructable detailing his DIY compost thermometer build:
Here are some basic instructions on how to build a $2 compost thermometer using readily available supplies. It looks crappy (in a good rustic kind of way), but works great and uses few materials.
You really don’t need to read this… I like this design because it’s pretty functional, reaches the correct temperature faster, and looks cool, but you could just duct tape everything together in a minute and see if it works for you first.
120 seconds voice record – play back
A message recording board capable of recording 120 secs of audio by Rajkumar Sharma over at Electronics Lab:
This project is designed around ISD25120 which can store 120 Seconds audio. Recording and playback operations are controlled with tact switches. The kit has an onboard microphone and LED to indicate the functions of Play and Recording. IC has a re recordable non-volatile memory which means that the message will be stored even after the units are turned off and even when it is turned on again.
Dirty DIY stencils
Matt Mets of Blinkinlabs shared a tutorial on making solder paste stencils quickly by hand:
This is a truly quick and dirty method for making solder masks, and is nice because it only requires a few hand tools. It’s great for situations when you want to test a new design or make a single, small run of boards, but don’t want to waste time and money on a professional stencil.
Via the contact form.
Digitally controlled bench PSU project update
An update on Bertho’s digitally controlled bench PSU project, we wrote about it previously:
Finally some spare time to get the PCBs finished and on order. Lets see how many brainfarts are there to be discovered ;-)
Expected delivery in a couple of weeks, so there is some time before I can dive into the lab to do some testing.A rendering of the PCBs…
Power board
NTSC video signal generation demystified
Sagar has posted the final installment on his blog series demystifying the NTSC video standard.
NTSC progressive scanning mode and simpler sync methods are not well documented and this issue is addressed here. Producing video signals by going to lowest hardware level is fun and satisfying. With the number of very capable digital controllers available to hobbyists today, it has become possible to generate analog video signals entirely in software. With the techniques and sync patterns presented here, generating “software video” becomes a much easier task.
For an index of all seven tutorial segemtns visit Sagar’s blog.
Via the contact form.
Cheap entropy using RTL-SDR dongle
We’ve seen the RTL-SDR dongle used for a number of interesting projects, but here’s an unusual one not directly related to signal monitoring. Noel Bourke was considering the topic of entropy and randomness as it relates to encryption and came up with a unique use for the RTL-SDR.
When RTL-SDRs came on the market back in 2012 my first thought was “Oooh! a cheap homemade radio noise RNG!”. RTL-SDRs are USB TV tuners based on the RTL2832U chipset. Rather than building a different tuner for each market’s frequencies, Realtek built a cheap wide-band software defined radio, wrote the TV tuner in software and then built millions of units for less $1 a piece. So we can just turn the RTL-SDR on, sample everything it can see and instead of a TV tuner we have an ultra wide-band radio entropy source! Before reinventing the wheel I did a quick search and found Paul Warren’s RTL-Entropy.
So today I was installing ArchLinux on one of my computers and decided it would be probably be a good idea to document a few things I usually do. And if I do that, I might as well just stick my documentation on a blog in the hope it’s useful to someone else.
You can find Noel’s post on SecurityLaxity.
App note: Surface mount LEDs- applications
How to use SMD LEDs to replace through hole LEDs, this app note (PDF) from OSRAM discusses about light guides/pipes, backlighting and lenses to channel its display efficiently.
The use of SMT-TOPLED varies greatly from the use of traditional through hole LEDs. Historically through hole LEDs have been incorporated directly into front panels using the leads as a stand. Due to the automated nature of SMT assembly, and the size constraints of SMT component and assemblies, SMT-TOPLED applications are different from through hole applications. For SMT applications the LED is often 10 mm or more from the front panel. Employing light guides can create the optimum display to the final viewer. Because of the size and radiation pattern of the Osram Opto Semiconductor SMT-TOPLED the final light emitting surfaces can be created in almost any shape. Lenses can also be combined with SMT-TOPLED. Because of the uniform repeatable radiation pattern, the lens design can be matched to the exact customer requirements. Additional applications include backlighting of symbols and liquid crystal displays.
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 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:
- Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
- Facebook PCB Friday. Free PCBs while you wait for the weekend
- Free PCB Sunday, right here on the blog
- Check out how we mail PCBs worldwide
App note: Analog switch allows USB switching at low voltages
Multiplexing USB pins using analog switches solves pin sharing between devices. Here’s a good app note(PDF) from ON Semiconductor.
NLAS2066 is a dual SPST (Single Pole Single Throw) switch with over-voltage tolerance (OVT) in its input pins. The OVT feature permits the device to be used for the purpose of sharing of pins in size constrained applications. Shared pins permit the designer to have a smaller connector, saving cost on both male and female portions.
App note: DS2406 PIO command examples
An app note from Maxim, DS2406 PIO command examples:
This application note reviews and provides example commands for using the I/O capabilities of the DS2406.
DirtyPCB IKEA Samtid mood-light upgrade
madworm writes:
Just wanting to share one of my latest projects, made possible by DirtyPCBs. I got a lot of good boards (actually 2 designs) and saved 25$ using this service. Very nice.
It’s a simple thing, just a micro (ATmega168) + a bunch of WS2812B LEDs. Main purpose: more colours :-)
It’s meant to fit nicely into IKEA Samtid lamps, runs with 5V DC and takes up to 2.75A. The control module is removable, so one doesn’t have to rip the lamp apart every time you change code. I used microMaTch connectors, as they’re somewhat low profile, at least compared to standard headers, and provide quite good mechanical support.
All design files + code are available via My2µF blog.
Check out the video after the break. Continue reading “DirtyPCB IKEA Samtid mood-light upgrade”
What happened to Motorola
An interesting take on the formation of what todays china mfg is. (via Adafruit blog), h/t Tom Keddie
Introducing Bo & Yana – robots helping kids learn to code
Two of the guys working on this pass through Shenzhen regularly, no end to the cool stuff going on around here:
Play possibilities are endless
A pusher bar to clean up your room, or an arm to present a flower to a friend — there are many accessories to give Bo & Yana new capabilities!
Use Music, Animation, Stories and Puppeteering to program Bo & Yana.
Bo can detect Yana (and another Bo too!) using RoboSense — making it possible for robots to play hide-and-seek, tag and soccer!
Teach your old toys new tricks with our Building Brick Extensions! They are compatible with Lego® bricks, Technics, and Mindstorms kits (also Hero Factory). You can build Bo & Yana into anything you imagine.
Now Bo can be a spy, a messenger or a treasure hunter.
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 every week:
- Free PCB Sunday. The classic. Every week, get free PCBs right here on the blog comments
- Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
- Facebook PCB Friday. Free PCBs while you wait for the weekend
- Check out our video on how we mail PCBs worldwide.
Continue reading “Free PCB coupon via Facebook to 2 random commenters”
Week in (p)review August 29, 2014
Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon.
- Say hello to the new server!
- ATX Breakout Board V1.1 Acrylic case back in stock
- Maker Villa Penang – We got to attend the first two days full of hacks, food, and making new friends
- Check out kjetilei’s Charliecube in the project log forum
Coming up:
- Free PCBs via Facebook on Friday
- App notes on the weekend
- Free PCB Sunday
- Free PCBs via Twitter on Tuesday
- Weekly roundup and preview every Friday
Maker Villa Penang workshop
Maker Villa Penang started out with a breakfast of local street food at the historic Ren I Tang hotel, we grabbed a bag of Indian pastries and curry dips on the corner and met the group.
Hackers with style. Maker Villa Penang rented this entire building in a UNESCO world heritage site for our accomidations. It’s a far cry from City Inn in Shenzhen, where we put most visiting hackers.
After breakfast we headed to the industrial area where most big brand flash storage and chip manufacturers have a factory. Penang has been a chip making power house since the 1970s.
Postbag from Sparkfun ‘Ding and Dents PCBs’
Jan Henrik writes, “I just recieved some postbags from Sparkfun with Ding and Dents, so I decided to make a review, what I got and if its worth it…”
Via the contact form.
Say hello to the new server!
If you can see this post you have reached the new server! Please report any problems you experience. We’re now running on Varnish and some cached stuff may need tweaking before it runs smoothly.
We will post the full setup of the server next week.
BT-C3100 intelligent battery charger teardown
Alan Parekh of Hacked Gadgets writes:
Thanks to GearBest for sending in this Opus BT-C3100 V2.0 Intelligent Battery Charger for review. at a quick glance this charger might look like any other charger that you see at the grocery store. Your generic store bought brand probably also has 4 charging bays for AA and AAA batteries, it probably has 2 charging circuits which places 2 cells in series to charge them, it most likely has 2 charging lights which just turns off when charging is done. If you leave the batteries in your generic charger you will most likely have batteries that have been overcharging or running down. Also your generic charger can probably just charge one chemistry of battery.
When you have a closer look at the Opus BT-C3100 V2.0 Intelligent Battery Charger you can see how this system differs from your every day generic battery charger. It can auto detect and charge NiCd, NiMH and Li-ion batteries. It charges each cell independently preventing bad cells from interfering from other cells from charging properly. Forget charging lights, this has a full LCD display that provides tons of status. It will monitor batteries that are left in the charger and keep them topped up and ready to go. From here the features go on and on. Don’t let the small package fool you, there is a ton of smarts and features built into this small package.
Have a look at the pictures below and in the video for a look inside the charger. The construction is a dual sided SMD load, the construction looks very professional. The battery contact spring tensioners work well and the connection to the PCB has been beefed up with a thick metal bar…
Via Hacked Gadgets.
Check out the video after the break. Continue reading “BT-C3100 intelligent battery charger teardown”