Android Doorbell Notifier

July 7, 2014 by Eric Evenchick 38 Comments

It’s always unfortunate to find a FedEx tag on your door saying you missed a delivery; especially when you were home the whole time. After having this problem a few times [Lee] decided to rig up a doorbell notifier for his Android phone.

[Lee]’s doorbell uses a 10 VAC supply to ring a chime. To reduce modifications to the doorbell, he added an integrated rectifier and a PNP transistor. The rectifier drives the transistor when the bell rings, and pulls a line to ground.

An old Netgear router running OpenWRT senses this on a GPIO pin. Hotplugd is used to run a script when the button push is detected.

The software is discussed in a separate post. The router runs a simple UDP server written in C. The phone polls this server periodically using SL4A: a Python scripting layer for the Android platform. To put it all together, hotplugd sends a UNIX signal to the UDP server when the doorbell is pushed. Once the phone polls the server a notification will appear, and [Lee] can pick up his package without delay.

Extending EagleCAD With Python

June 30, 2014 by Brian Benchoff 45 Comments

eagle Although it’s derided for not being open source, EagleCAD is an extremely popular piece of schematic and PCB layout software. Most of the popularity is probably due to the incredible amount of part libraries – it’s certainly not the features Eagle has to offer or its horrible scripting capabilities. [Rob] had enough of the lack of good scripting support in Eagle, so he’s been spending his time making Eagle’s ULP work with Python. He’s only been at it a short time, but already it’s much more usable than the usual Eagle scripts.

Below you can check out a pair of videos of [Rob]’s Python tools for Eagle in action. The first video goes through aligning a few symbols and creating a board outline (with proper curves!) from a DXF file. The second video shows exactly how valuable these tools are when laying out a board: imagine hundreds of LEDs and resistors automatically aligned to each other with a single click of a mouse. Beautiful.

All the PyEagle stuff is available on [Rob]’s github, with a DXF importer, group manager, and alignment tool included. Now that everything’s Python, it’s easy to build your own tools without relying on Eagle’s odd ULP language.

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WiFinder Is A Python Driven Roommate Warning System

June 28, 2014 by Rick Osgood 30 Comments

WiFinder

We’ve all been there. Your roommate is finally out of the house and you have some time alone. Wait a minute… your roommate never said when they would be back. It would be nice to be warned ahead of time. What should you do? [Mattia] racked his brain for a solution to this problem when he realized it was so simple. His roommates have been warning him all along. He just wasn’t listening.

Most Hackaday readers probably have a WiFi network in their homes. Most people nowadays have mobile phones that are configured to automatically connect to these networks when they are in range. This is usually smart because it can save you money by not using your expensive 4G data plan. [Mattia] realized that he can just watch the wireless network to see when his roommates’ phones suddenly appear. If their devices appear on the network, it’s likely that they have just arrived and are on their way to the front door.

Enter wifinder. Wifinder is a simple Python script that Mattia wrote to constantly scan the network and alert him to new devices. Once his roommates are gone, Mattia can start the script. It will then run NMap to get a list of all devices on the network. It periodically runs NMap after this, comparing the new host list to the old one. If any new devices show up, it alerts with an audible beep and a rather hilarious output string. This type of scanning is nothing new to those in the network security field, but the use case is rather novel.

Autonomous Balloon Popping

June 20, 2014 by Eric Evenchick 7 Comments

Taking on an autonomous vehicle challenge, [Randy] put together this drone which can locate and pop balloons. It’s been assembled for this year’s Sparkfun Autonomous Vehicle Competition, which will challenge entrants to locate and pop ~~99 luftbaloons~~ red balloons without human intervention.

The main controller for this robot is the Pixhawk, which runs a modified version of the ArduCopter firmware. These modifications enable the Pixhawk to receive commands from an Odroid U3 computer module. The Odroid uses a webcam to take images, and then processes them using OpenCV. It tries to locate large red objects and fly towards them.

The vision processing and control code on the Odroid was developed using MAVProxy and Drone API. This allows for all the custom code to be developed using Python.

The Sparkfun AVC takes place tomorrow — June 21st in Boulder, Colorado. You can still register to spectate for free. We’re hoping [Randy]’s drone is up to the task, and based on the video after the break, it should be able to complete this challenge.

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How To Upgrade Jasper’s Voice Recognition With AT&T’s Speech-to-Text API

June 7, 2014 by Rick Osgood 9 Comments

Jarvis upgrade

Jasper is an open-source platform for developing always-on voice-controlled applications — you talk and your electronics listen! It’s designed to run on a Raspberry Pi. [Zach] has been playing around with it and wasn’t satisfied with Jasper’s built-in speech-to-text recognition system. He decided to take the advice of the Jasper development team and modify the system to use AT&T’s speech-to-text engine.

The built-in system works, but it has limitations. Mainly, you have to specify exactly which keywords you want Jasper to look out for. This can be problematic if you aren’t sure what the user is going to say. It can also cause problems when there are many possibilities of what the user might say. For example if the user is going to say a number between one and one hundred, you don’t want to have to type out all one hundred numbers into the voice recognition system in order to make it work.

The Jasper FAQ does recommend using the AT&T’s speech-to-text engine in this situation but this has its own downsides. You are limited to only one request per second and it’s also slower to recognize the speech. [Zach] was just fine with these restrictions but he couldn’t find much information online about how to modify Jasper to make the AT&T engine work. Now that he’s gotten it functional, he shared his work to make it easier for others.

The modification first requires that you have at AT&T developer account. Once that’s setup, you need to make some changes to Jasper’s mic.py module. That’s the only part of Jasper’s core that must be changed, and it’s only a few lines of code. Outside of that, there are a couple of other Python scripts that need to be added. We won’t go into the finer details here since [Zach] goes into great detail on his own page, including the complete scripts. If you are interested in using the AT&T module with your Jasper installation, be sure to check out [Zach’s] work. He will likely save you a lot of time.

HAL Is Duct Tape For Home Automation

May 31, 2014 by Rick Osgood 17 Comments

HAL Home Automation

When it comes to home automation, there are a lot of different products out there that all do different things. Many of them are made by different companies, and they don’t often play very well together. This frustration ultimately led [Daniel] to develop his own Python based middleware solution to get these various components to work as a single cohesive system. What exactly did [Daniel] want to control?

First up was the door lock. [Daniel] lives in an apartment building, so there are actually two locks. First, a visitor must be allowed into the building by pressing a button on the intercom system in the apartment. Second, the apartment door has its own dead bolt lock that needs to be opened and closed. [Daniel] was able to control the building’s front door using just a transistor hooked up to an Arduino to simulate the press of the physical button. The original button remains in tact so [Daniel] can still easily “buzz” in a visitor.

The apartment’s dead bolt was a bit trickier. There are off-the-shelf solutions to control a dead bolt, but they are often expensive. [Daniel] built his own solution using a simple servo motor bolted to the door. The servo is controlled by the Arduino which is in turn controlled via two broken intercom buttons that already existed within the apartment. The buttons were originally used to either speak to or listen to a visitor before buzzing them into the building. They had never worked for [Daniel] so he re-purposed them for his own project. The whole DIY door locker is enclosed in a custom-made laser cut wooden box.

Click past the break for the rest of [Daniel’s] story.

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Arduino Garage Door Opener Is Security Minded

May 25, 2014 by Rick Osgood 13 Comments

Do it yourself garage door openers must be all the rage nowadays. We just got word of another take on this popular idea. [Giles] was commissioned by his friend to find a way to control the friend’s garage door using a smart phone. The request was understandable, considering the costly garage door remote and the fact that the buttons on the expensive remote tended to fail after a while. The inspiration for this project came from some YouTube videos of other similar projects. Those projects all paired an Arduino with a Bluetooth headset in order to control the door from a mobile phone. [Giles] understood that while this would get the job done, it wouldn’t be very secure. Bluetooth headsets typically connect to mobile phones using a four digit PIN. Many of them have known default PINs and even if the default is changed, it wouldn’t take very long to guess a four digit PIN. [Giles] knew he had to find a more secure way.

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