ChainringGen – making a chainring with open source software

Rich Olson writes:

ChainringGen is an OpenSCAD script I wrote that can generate a bike chainring with any specifications you like.
You can download ChainringGen here.  You can control parameters like bolt-circle-diameter (BCD), number of bolt holes, number of teeth and other stuff.
I primarily created ChainringGen because I thought designing / milling my own 110 BCD 39 tooth chainring would be the most practical and economic way to obtain one.
I also wanted to explore ways I could get from an OpenSCAD design to an object created on my CNC mill.  It’s a bit trickier than just exporting an STL file.
The video above includes instructions on how to use ChainringGen in conjunction with other open-source tools to actually make a chainring out of 7075 aluminum using an inexpensive CNC mill.

More details at Nothinglabs project page.

Via the contact form.

Matchbox car

IMG_20150808_132911

Shane has been working on making small robots and made a prototype of a matchbox car,  a robot car that fits inside a matchbox:

This build consists of a tiny DC motors ripped from a pair of 9g servos, a h-bridge motor controller, an el-cheapo 8 bit pic and a 100mAh 3.7V LiPo battery.

Project info at Wattnotions project page.

Via the contact form.

Check out the video after the break. Continue reading “Matchbox car”

Arduino-based “Analog” slow cooker controller

IMG_0884_SM

Dan Ternes blogged about his Arduino-based controller for analog slow cookers:

With the AC power control figured out, I considered the User Interface. I opted for something simple. The Adafruit RGB LCD Shield would work well as it had both a display and buttons built in. Sure, I could have beat this project about the head and neck with “IoT”-this and “ESP8266″-that, but I was feeling lazy and just wanted a simple timer control. Of course, there’s nothing that says I won’t add some kind of wireless connectivity, but for now, local control is fine.

Code is available on github.

More details at Maniacal Labs project page.

#FreePCB via Twitter to 2 random RTs

buspiratev383

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 it every Sunday, right here on the blog
  • Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
  • Facebook PCB Friday. Free PCBs will be your friend for the weekend

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Check out how we mail PCBs worldwide video.
  • We’ll contact you via Twitter with a coupon code for the PCB drawer.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.

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.

R/C Aircraft lighting controller

file

Ezflyr shared his R/C Aircraft lighting controller in the project log forum.  He writes:

I’m an avid R/C modeler, and I’m just finishing up my latest ‘winter building’ project, a 150″ wingspan Douglas DC-3!  I wanted to add a continuously flashing strobe light on the vertical stabilizer of the airplane, and remotely controlled Red (left) and Green (right) navigation lights on the wingtips. To satisfy this need, I decided to ‘roll my own’ R/C Aircraft Lighting Controller to finish off my DC-3 airplane!
This design is based on the PIC 12F629 microcontroller. The code for this project is written in ‘C’, using the CCS ‘C’ compiler. The schematic and board were done using Cadsoft Eagle software, and the PCB fabrication was done by OshPark!

Via the forum.

Homemade x-ray inspector reveals PCB secrets

capture_021

John McMaster has written an article detailing his homemade x-ray scanner:

In some previous posts I talked about getting an x-ray head working, reverse engineering an x-ray sensor, and working with LinuxCNC.  In this post I put them all together so that I can take a bunch of x-ray snapshots across an entire PCB.  This allows me to more quickly reverse engineer PCBs.

Project info at John McMaster’s blog.

Via Make.

Continue reading “Homemade x-ray inspector reveals PCB secrets”

Automatic feeder mod makes cat work for food

cat_feeder

Here’s a cool automatic feeder for your cat that dispense food in exchange for a wiffle ball by Benjamin Millam.  He wrote a post on his blog detailing its assembly:

I used an Adafruit RFID reader to detect RFID tags embedded in the wiffle balls: the balls are cut slightly, enough to slip in an RFID tag; when the ball drops it rolls down an incline and passes the RFID reader, which reads the tag and initiates the Arduino’s feeding program. The Arduino switches on the relay that closes the feeder’s power circuit, and voila, food.

Project info at Benjamin Millam’s blog.

Via Technabob.

Check out the video after the break. Continue reading “Automatic feeder mod makes cat work for food”

ESP8266 Arduino NetIO Server demo

servo_thumb

Peter Scargill writes:

This week as regular readers know I was far away from our little home in Spain – in fact I was at MIT (Massachusetts Institute of Technology)  in Boston, helping promote ESP8266 technology (why? because I could).
Along the way I met up with Ivan Grokhotkov who as some of you know has done a lot of work to bring the Arduino environment to the ESP8266 community.  As part of what we were doing at MIT, Ivan and I decided to put together a simple demonstration – this would use NETIO (my favourite IOS/Android visual interface) and ESP8266-Arduino to help an ESP board drive a servo via wireless control.

Details at Peter’s blog.

Simple and small temperature fan control

FanControl4

Xristost published a new build, a simple and small temperature fan control:

I published this schematic long ago in this article: Adjustable power supply and since then I made some improvements in PCB to make the board as small as possible. The idea is to be easy to attach the whole board to the heat sink which we want to monitor. The board is only 27mm x 27m

Project info at DIYfan blog.

Free PCB Sunday: Pick your PCB

IRToy

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:

Continue reading “Free PCB Sunday: Pick your PCB”

App note: Live insertion using low voltage differential signaling

an_fairchild_an5047

Hot swapping capability of LVDS, app note from Fairchild Semiconductor. Link here (PDF)

Supporting live insertion or hot swapping is important in certain applications such as the ones used in telecommunications systems. These applications require maintenance, upgrades, and repairs to be conducted without shutting down the system or causing disruptions to traffic on the backplane. Inserting and removing cards on a backplane is a capability often required for maximizing system uptime.
This paper will discuss how Low Voltage Differential Signaling (LVDS) technology supports live insertion for multidrop applications and hardware considerations to minimize the effects inserted cards have on a backplane.

 

App note: LVDS Fundamentals

an_fairchild_an5017

Here’s an app note on LVDS from Fairchild Semiconductor. Link here (PDF)

With the recent developments in the communications market, the demand for throughput is becoming increasingly more crucial. Although older differential technologies provide significant signal integrity benefits compared to single ended technologies, many of them consume much more power at lower throughput than LVDS.
The LVDS standard was created to address applications in the data communications, telecommunications, server, peripheral, and computer markets where high-speed data transfer is necessary. LVDS offers a low cost, high speed, low power solution when compared to the standards of the past.

App note: Using feature set of I2C Master on TM4C129x microcontrollers

apps

An application note (PDF!) from TI on using feature set of I2C Master on TM4C129x microcontrollers:

The inter-integrated circuit (I2C) is a multi-master, multislave, single ended bus that is typically used for attaching lower speed peripheral ICs to processors and micocontrollers. The type of slave devices range from non volatile memory to data acquisition devices like analog-to-digtal converter (ADC), sensors, and so forth.  This application report demonstrates how to use the feature rich I2C master on the TM4C129x microcontrollers to communicate with a host of slave devices in asystem.

Free PCB coupon via Facebook to 2 random commenters

KHOS-2-3-4-5-6P

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”

WiFi smoke detector

FU0VELAICX7JEWX

An instructables on how to make a WiFi smoke detector by Proto G:

This is a simple WiFI Smoke Detector that texts me when it senses smoke. I made this for my battery storage area in case of a lithium polymer fire. I still have all of my regular smoke detectors installed and I don’t suggest relying only on this, but rather as an extra layer of protection. If I had a house I would install a proper fire alarm system that calls the fire department, but I live in a small apartment so I can’t. I can set this one to email and call the local fire department as well(local laws apply). In my county it is allowed as long as you register it with the fire department. Either way, I would rather call the fire department myself when I receive multiple texts.

Check out the video after the break. Continue reading “WiFi smoke detector”

AMQUMO: A Xively AMbient QUality MOnitor built on ATmega328

avr_atmega_ambient_quality_monitor-atmega328

Davide Gironi published a new build, AMQUMO -an ATmega328 AMbient QUality MOnitor:

AMQUMO logs 4 environmental parameters:
-Humidity
-Temperature
-Ambient Noise
-Brightness

The data it is logged to the xively.com platform, and displayed to the user through 4 bi-color leds. It can be used to monitor you Office Ambient Quality over the parameters logged.
This project it is built upon the xively logger ATmega328 library
So, a web page can be used to setup network parameters, and xively tokens.  Network can be set using a Static IP, Gateway, NET Mask, or DHCP.
Obviously xively feed number and API token can be setup by that web page.

More details at Davide’s blog.

Check out the video after the break.

Continue reading “AMQUMO: A Xively AMbient QUality MOnitor built on ATmega328”

Teardown, repair & analysis of a Rohde & Schwarz FSH3 3.0GHz portable spectrum analyzer

A teardown and repair of a Rohde & Schwarz FSH3 3.0GHz portable spectrum analyzer from The Signal Path:

In this episode Shahriar examines a faulty R&S FSH3 100kHz – 3.0GHz Portable Spectrum Analyzer. This exceptionally dirty unit does not power on and is missing a power supply and battery. After verifying the correct operation of the battery charger circuit and keypad the problem is traces to a damaged SOT-23-6 MOSFET device which is part of a fly-back DC-DC converter. A replacement MOSFET with a lower current rating proves to be a failure as the device fails on startup. A higher rated MOSFET resolves the problem and device begins to operate correctly.
The block diagram of the system as well as a detailed block diagram of the RF section is presented and correlated with the teardown of the RF section. The super-heterodyne down-conversion circuits and components are examined.

 

Irrighino, a complete watering system based on Arduino Yun

irrighino_logo_top

Here’s Luca Dentella’s new project Irrighino, a complete watering system based on Arduino Yun.  It features a user friendly AJAX interface and a fully-customizable open source firmware.

The main features are:
-a configurable number of solenoid valves
-an AJAX web interface
-a weekly schedule
-manual activation / deactivation

An Arduino Yun – the “brain” of irrighino – is connected to the switch panel (with phsical switches and status leds), the rain sensor and the relay board that controls the solenoid valves. Yun is also connected to the home wifi network: a device (PC, smartphone…) connected to the same network can open the irrighino webinterface and configure and control it.

Code is available on Github.

Project info at Luca Dentella’s project page.

Check out the video after the break. Continue reading “Irrighino, a complete watering system based on Arduino Yun”

Making an intelligent cap with Crowtail modules

FMZF6R5IBLV5STN

Need an idea for a present? Gebera shares us a present he made for his Dad, an intelligent cap:

It can be a great help to let my father know the time and have a rest if the UV ray is too high and be careful when come back late in night. With this cap, i can not so worry about my father.

You can see the full step by step guide at Instructables.

Via the project log forum.