Mongodb

MongoDB on Raspberry Pi Model 1

One of my projects is to automate a LEGO City, especially the train section. For that i need a place to save all the information. Initially choose a SQL database (MySQL), but as necessary to create custom tables for each case and create relations. But as i didn’t know what information was supplied by the City and i would need a communication protocol ( i’ll use MQTT. In the future i’ll write a tutorial how to use it) i choose a NoSQl database, MongoDB.

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RC Car Arduino Controlled

In this year Eletrónica e Informática (http://ei.aicb.pt) i presented a project prototype of an autonomous car controlled by an Arduino Nano.
The project was simple: a r/c car was controlled by an Arduino nano and uses an ultrasound sensor to detect obstacles that was in his front. If it was detected an obstacle, it stops, moves back and changed direction.

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S-Video – RF Conversion

Today I came across a relevant situation. I was necessary to show a Microsoft PowerPoint presentation an a TV. But the TV and the laptor were 50 meters away, the laptop could not be places near the TV and the only cable that was installed between the two was a coaxial RF cable. The only laptop output that could be used was an S-Video.

How to convert S-Video to RF only with the existing equipment?

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Sensor de detecção de obstáculos

Keyes IR Obstacle Sensor with Arduino

A project that i was developing for a workshop about electronics is a LEGO® train controled by an arduino. The project it’s explained in here. There were two situations where it was necessary to detect the train’s position. When this is was arriving to the station and when is was on an external track. First i’ve tried to use “Line Tracking” sensors but didn’t have enough range. On the second try used a Keyes IR Obstacle Sensor (this model) and they worked.

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