After months of good work, the quality of my 3D prints started decaying until there was no extrusion at all.

This is usually caused by a clogged nozzle: low quality impure ABS filaments leave traces of other material sticked to the nozzle channel. You can solve this easily by leaving the nozzle soaked on acetone overnight.

But after I removed the nozzle to clean it, I realized that I sill couldn't extrude. So, I disassembled the whole extruder and saw that the fault was on the teflon (PTFE) tube, as you can see on the following image:

ESP-8266 is an easy and low-cost alternative to the expensive Arduino WiFi shields. While those shields can cost over USD 50, you can find an ESP module for less that USD 3 at ebay

There are several ESP module models around there. All of them are based on the same IC. This article is based on the ESP-01, which is, probably, the most common model.

All ESP-8266 modules are programable. You can use the default factory firmware or you can write your own firmware and upload it to your module. My module came with the firmware version 0018000902-AI03.

Bem vindo à minha horta wifi:

A caixinha amarela acima monitora a umidade do solo e a quantidade de luz recebida pelas plantas. Estes dados são capturados continuamente, e enviados a um servidor, que gera relatórios e alarmes:

This is a very simple weekend project: A gas leakage alarm for your kitchen.

It's based on a MQ-2 sensor, which detects LGP (Liquefied Petroleum Gas), alcohol, smoke, propane and some other gases. It comes froma family of sensors, all of them with the same pinout, so any project using them can be easily "ported" to detect different gases. For example, MQ-7 detects Carbon Monoxide and ME2-O2 detects Oxigen.

This is the result of my home-made motion capture system. I've used it to animate videogame characters for another project

Of course, there's a lot of free game assets around the net, but, as usually, it's funnier to go with your own solution.

On the video, the character seems to lose a keyframe, but I've managed to fix this at the game

 

This month I was invited to help at a local videogame faire, Arena Game Show. The guys from Python Brazil, the Brazilian Python community, got a stand at the event and were planning some workshops and classes.

This is the game I brought there:

 

I was getting too much distortion on my drawings on the oscilloscope. After checking that the waveform was correct, I started trying different soundcards, and figured out they can make a huge difference on the final image.

Here are what I found about them

I tried the following soundcards:

I've been working on a full-body homebuilt 3d scanner.

Here you can play with a virtual version of me:

This is a low-poly 3D model. These files are usually too big for web, so I reduced it to around 4k vertices. The original was 100 times bigger.

My homebuilt 3d scanner is comprised by 3 Kinect sensors and two lighting poles. I used a led strip for the poles. They are used to set an even lighting around the 3d object.

Cassapa is a system to help aiming at pool games. It uses augmented reality to help the player to adjust the cue direction. Check this video:

How it works

Everything starts with a webcam, fixed at the ceiling above the pool table.