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Enchanted Objects

25 Posts authored by: amgalbu Top Member
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After building the MagicHat, I was wondering: what if I want to wear the hat at a party? I need a bow tie... so this is a quick tutorial to build the bow tie for your MagicHat     IMPORTANT NOTES 1. it's better to wear the bow tie with a shirt 2. charge MagicHat battery before the party 3. remember to shave!! 4. say thanks to balearicdynamics  for this wonderful idea   ...
This week I completed my project for the Enchanted Objects design challenge. It has been funny even if some external activities (namely work and family :-)) didn't allow me to get a more in-depth view of some aspects. I will now try to assess whether I met the requirements of this challenge   Security The MagicHat does not publish anything on the Internet. Local connections are encrypted through SSL and access to web UI is protected by user authentication Accuracy: how well does the propos ...
Even if the MagicHat is not sending any sensitive data out on the Internet, it's always important to make communication as secure as possible. For this reason, I will implement HTTPS communication between the web browser and NodeJS running on Arduino Yun. Since the communication is now encrypted, we can use basic authentication (were password is just Base64 coded, but not encrypted) To add HTTPS support, we need to:   Install OpenSSL OpenSSL setup can be downloaded from here. Installation ...
This is the last week of the challenge The hardware and software are almost completed, so it's time to build the real hat. In a previous post, I started building some parts of the hat. First of all, I cut out from plywood a circle that will be the brim of the hat. I then fixed the blood pressure measurements device to the plywood using some self-tapping screws   Then I covered everthing with a fabric. It's not very fashion, but that's what my mother has in house     I the ...
Thanks to the Text-To_Speech engine, I can easily add a nice function to the MagicHat: the capability to say wisdom phrases while it's idling The implementation will be based on a web service that provides quotes as a JSON document I found a lot of alternatives on www.mashape.com and I selected the quotes service provided by quotbook.com The URL to invoke to get a new quote has the following format https://yusufnb-quotes-v1.p.mashape.com/widget/~{search}.json where {search} is th ...
amgalbu

19 - MagicHat first words

Posted by amgalbu Top Member Jun 12, 2015
I completed the mouth and the MagicHat now can speak. I had to make some changes to the circuit for reading audio output. The new version includes two resistors and a capacitor to shift up voltage level by 2.5V     Using an headphone, I cut off one of the speakers and added a connector to be connected to the Arduino board     The video shows MagicHat saying its first word. "Hello". Unfortunately audio quality is not that good due to my smartphone limitations, but it gi ...
The last missing piece of hardware to complete the MagicHat is the mouth The mouth will be a simple VuMeter that continously read the line output from the USB audio card and switch on LEDs accordingly LEDs will be switched on from the center to the sides to give the impression that the mouth is more open when the sound is louder   Here is the circuit schematic     and here is the flowchart of the code that switches on and off LEDs     NOTE: (threshold1 < thre ...
I went through and interesting article here   Basically, what they state is that once you got the correspondence between biosignal ADC reading and maximum blood pressure, you can determine systolic and diastolic pressure by applying a linear equation on the minimum and maximum ADC reading for each heart beat   So I have a very simple (yet not optimal) solution to the problem of determining the systolic and diastolic pressure The flow chart of the process for measuring blood pressure ...
Not that I can play an mp3 file, let's find a way to build a simple TTS speech As we live in a connected world, why not leveraging the power out there on the web to overtake hardware limitations?   I found an interesting site here http://tts-api.com/   that provides a text-to-speech web service   To convert a text programmatically from NodeJS, the URL to invoke is the following one   var mp3url='http://tts-api.com/tts.mp3?q='+encodeURIComponent(text);   Given this url, ...
After finishing the data acquisition part of the project, let's see how to make the MagicHat a little more... magic   To make Arduino Yun speak, I first need an external USB audio card like this one here     Then, I need to install an mp3 player that will play a file stored on SD card. Installing the mp3 player is just a few packages away...   opkg update opkg install kmod-sound-core opkg install kmod-usb-audio opkg install madplay   Since the control logic runs ...
I finally succeeded in measuring blood pressure in an almost reliable way. In this post I will show the results of my experiments   In order to determine the law between the value returned by the Force Sensor Resistor and the blood pressure, I run some comparison tests. Basically, I measured my real blood pressure with a normal home medical device (see picture) and associate the readings of the medical devices with the corresponding ADC reading of the FSR. I made a test on myself (I have a ...
In this post we will have a look  at how the client side of the web application is implemented For the web client I used the Angular JS framework and the graphical components made by Telerik. This components are not free (I have a licence since I used those components at work, but they can be easily replaced with free and/or open source components)   The most interesting part is how the web socket is created and how data is processed to update the web page. The web socket is created ...
While struggling to complete the blood-pressure measurement device, let's have a look about how to show measured value   In this project, measures will be communicated to the user in two way through a web interface that can be accessed by any device running a web browser through a Text-To-Speech engine   As I'm still waiting for the components required to build the Text-To-Speech engine, in this post I will focus on the web interface The web interface will be built using node. Th ...
The blood pressure measurement system revealed to be more challenging than I expected... As a matter of fact, the pulse detection algorithm takes up most of the Atmel 32U4 resources, thus leaving too few time to other tasks. This has some counter-effects, the most noticeable being a non-uniform movement of the continuous rotation servo. I tried several workaround, like moving the pulse detection algorithm in Timer3 ISR instead of Timer1 ISR (and obviously forcing the Servo  library to use ...