Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon.
Coming up:
A Static DOM XSS scanner by Ajin Abraham, that is available at Github:
Static DOM XSS Scanner is a Static Analysis tool written in python that will iterate through all the JavaScript and HTML files under the given directory and will list out all the possible sources and sinks that may cause DOM XSS. At the end of the scan, the tool will generate an HTML report.
Mat from Techmoan writes:
In this review we’ll find out exactly what you get for your money and whether this stripped down GoPro is worth the price premium over the SJ4000. I’ll run a few head to head video quality tests and list what features each device has in its favour. Ultimately though its down to you to choose the camera that you prefer. I’ll present the evidence but you have to make the decisions.
Here’s an automatic watering system using AVR from Gadgetronicx:
Primitive irrigation systems possess many drawbacks as it fails to conserve water and human energy. So introducing Automation in it can help us to overcome these drawbacks and pave way to conserve water. This can be done with a simple Soil moisture sensor and a Microcontroller, AVR in our case. You can try out this system to automate watering the plants in your home at affordable cost.
This small IR Toy case by GHPS is up on Thingiverse:
Sick of beige cases? Then print it in blue, red, black – or the color that you want…
The irToy by dangerousprototypes is a small, universal infrared controller for the USB bus. It can receive and send arbitrary ir signals – and is completely open source.
But comes quite naked without any case.
This enclosure is as small as can be allowing it be attached to the screen or desktop case. The front provides posts for an ir foil to shut the box close and still receive/send ir signals.
More cool DIY cases here.
You can get IR Toy v2 for $22.05, including world wide shipping.
XenonJohn posted detailed instructions of how to make this Self-Balancing Raleigh Chopper. He writes:
Data from the IMU is read by the Arduino Mega 1280. I use a Mega 1280 because they are a lot cheaper online than the 2560, and about the same price as an Uno. They have several hard wired serial outputs which means I can conveniently use one of these to send motor control data to the Sabertooth 2 x 25 Amp power controller, and another to send data to the serial-LCD screen. The Deadman switch and steering buttons (actually brake levers from children’s e-scooters) when pressed will connect their respective Mega pins to ground. The deadman is for safety, if you let go of it all power to the motors will stop after half a second. Digital Pin 12 is connected to an LED. This LED stays lit on startup and goes out after a few seconds when the machine is ready to be brought “level” at which point it will start to balance itself. The potentiometer in the diagram is actually on the left handlebar and is a Magura 5K potentiometer “twist-grip” throttle handle designed for electric vehicles. Turning it makes the machine lean forwards a little, and so it starts to roll forwards. Let it spring back and machine will lean backwards a little and slow down. It makes a very effective method of controlling speed (as well as simply leaning like you would on a Segway).
Via Hacked Gadgets.
Check out the video after the break. Continue reading “Self-Balancing Raleigh Chopper”
Kaspar of Monostable shared this helpful purchasing tool the 1clickBOM, a browser extension to quickly add electronic components to shopping carts:
1clickBOM is purchasing tool that let’s you keep one bill of materials (BOM) for items from multiple retailers. It’s a browser extension that fills your online shopping carts for you. To add items to 1clickBOM you simply paste from a spreadsheet or visit an online .tsv file.
Which retailers?
Currently supported retailers are:
-Digikey
-Mouser
-Farnell/Element14
-Newark
-RS
Code is available on Github.
Why did you choose Dirty PCBs? Was there something else you liked about them? Adrian Jones over at WoodUino tried it out:
As you can see, I chose a white coating for the boards but they offer many colours at no extra cost. The plating is excellent and the boards soldered easily. The component silk-screen is clear but all over the place – my fault because I didn’t bother to take the time to pretty it up. The boards are clean and tidy and look very professional.
Here’s a different and unconventional way to view a VHS tape (as if VHS tapes aren’t considered unusual enough today). DogsRNiceMineCraft posted this video on YouTube showing video received using an RTL-SDR dongle.
I got a VCR today and wanted to see if I could receive the signal from the RF out using TV sharp. I wrapped the antenna cord that came with my dongle around the RF out cable from the VCR, but it only works if the cable is barely touching the RF out port.
An unusual proof of concept which could have other applications.
The TV Sharp program referred to by the video’s poster appears to be available for download from radioamatoripeligni.it (Note: website primary language is Italian.) It allows reception of certain analog video signals using the RTL-SDR.
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.
Davide Gironi writes:
This is an op-amp Electret Condenser Microphone Preamp board design for the use with microcontrollers ADC.
For the NPN version of this board, an for more information about microcontroller ADC and microphone input, please refer to this page
The proposed circuit is just a revision of a pretty usually op-amp electret mic preamplifier.
The selected op-amp is the TLC272, because it can be drive in single rail operation, it’s common mode input range, and has good noise performance. Also other op-amp could work. The op-amp is configured in inverting mode.
Check out the video after the break. Continue reading “An op-amp based Electret Condenser Microphone Preamp for microcontrollers”
James built a USB IR Toy v3 free 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, whatever – we’ll send you a coupon code for the free PCB drawer.
You can get IR Toy v2 for $22.05, including world wide shipping.
Via Twitter.
Teardown and hacking of Schlage smart door lock by Felix Rusu of LowPowerLab:
As the title suggests it’s a smart door lock with a for coded entry and is based on “Iris” which in turn uses ZWave RF wireless technology (made by Zensys), a closed source patented protocol+hardware stack that is OEM-able to automation system makers who want an “off-the-shelf” wireless stack to integrate into their product.
Check out the video after the break. Continue reading “Schlage smart door lock hack/teardown”
Check out Elpis’ FPV system in the project log forum:
I’ve started flying quadcopter and tricopters a few months ago and now I am going towards FPV (First Person View). So, instead of having all the cables around and the different components on top of the other I put the receiver inside the small LCD screen and connect everything internally. The result is compact and most of all cheap!
I am sure that I could do a better job with the cables!
Latter, I will include a video recorder, I will add a 3.5mm jack for the second output of the receiver and I am designing a diversity receiver as well (again it will go inside the plastic cases of the LCD screen). The first input of the receiver will use the already available circular polarised antenna and the second input will use a panel type or helical antenna!
And yes! Some DangerousPrototypes stickers making this prototype more “dangerous” and an official entry into the makers/hackers community!!!
For more information on this build, visit Embeddedday.
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:
Clever way using linear regulator’s enable pin implementing a voltage supervisory circuit control, an app note(PDF) from ON Semiconductors.
The combination of a voltage regulator and a voltage supervisor, is a popular circuit configuration. The addition of the supervisor ensures that the regulated output turns on and off at sufficient input voltages, as well as giving the system the luxury of a safe and ordered startup.
App note(PDF) from ON Semiconductor.
The load switch is controlled by the system, and connects or disconnects a voltage rail to a specific load. By turning unused circuitry off, the system as a whole can run more efficiently. The load switch provides a simple means to power a load when it is in demand and allows the system to maximize performance.
868 MHz, 915 MHz and 955 MHz inverted F antenna (PDF) application note from Texas Instruments:
This document describes a PCB antenna designed for operation in the 868 MHz, 915 MHz and 955 MHz ISM bands. This antenna can be used with all transceivers and transmitters from Texas Instruments, which operates in these frequency bands. Maximum gain is measured to be −0.12 dB and overall size requirements for this antenna are 43 x 20 mm. Thus this is a medium size, low cost antenna solution.
Figure 1 shows a picture of the board being used to develop and characterize this antenna. The board is pin compatible with CC1110 EM and is equipped with two LEDs, a push button, a 10-pin debug connector and a 2-pin power connector for test and characterization purpose.
An app note (PDF!) from Renesas on how to minimize power consumption when sensing switch inputs
A switch input is one of the simplest interfaces to an MCU. However, when very low power designs are needed the pullup or pulldown resistor for the switch can draw a significant current. If the switch input is a momentary switch the current flow is very short so it is rarely significant. However, if the switch input is a door switch or level sensing switch
or any other switch which may remain in the active state for a relatively long time the energy used must be considered
Most of the discussion that follows gives examples for pull-up devices with the switches, the same principles apply for pull-down components. Also all the discussions assume that the EVdd = Vdd (all ports powered from the same supply voltage).
Rohit Gupta wrote a basic library for using MMA7361 3axis Accelerometer with Arduino, that is available at Github:
This library helps you to easily play with the almost universal 3 axis accelerometer available in most Hobby markets that is based on Freescale’s MMA7361.
In order to get in working you have to pull-up the sleep pin using a 10K resistor to the 3.3V pin. All other connections are labelled.
Via the contact form.
