Clever way of measuring defectiveness of cooling fans

Have you ever wandered how effective are cooling fans when compared to each other. Some of them are noisy, other quieter. But with more silence there comes a question – are they effective enough. Instead of probing with bare fingers, nop head decided build his own coolometer which would give some objective results. He surfed through various methods and instead of anemometer he decided to use a 12V 0.8W light bulb and measure the cooling effect – measure how fast bulb filament is cooled. Knowing that when bulb is cold, resistance is about 15 Ohms, when hot – resistance is ten times higher. He constructed Wheatstone bridge circuit where one resistor is replaced with bulb. To make it digital, he has chosen MicroView module which comes with Arduino and OLED … Continue reading

Wearable OLED display powered with attiny85

Wearable electronics is commonly used in many areas. We are not talking about professional stuff like medical devices, but more hobby corner. But who knows where is a limit. Today anyone can assemble wearable projects with cheap building blocks that are mostly based on Arduino. AwesomePCB have shared his instructable on how to build a wearable OLED display covered with leather frame that blends pretty well on fabric. He used small SSD1306 128×64 OLED display which is connected to small Attiny85 Arduino compatible board. Coin cell battery is enough to power it for quite some time. He paid some attention to details on how display is attached to leather piece and how this piece is snapped to clothes. You can do many fun stuff with the display including a temperature … Continue reading

Driving SSD1306 based OLED display with DMA library

People love using OLED displays in their projects because they offer better contrast, color depth and different feel from LCD. So there are plenty of OLED display modules ready to be used with microcontroller boards like Arduino. Adafruit also offers great 128×64 SSD1306 based OLED display which has great library for Arduino. But problem is that there are so many Arduino variations with different processor families that using one generic library doesn’t ensure its efficiency. So the guys from grav-corp decided to tweak the library so it would work with Arduino Due much faster because of DMA. Arduino Due is equipped with ARM microcontroller which most of the features aren’t used by standard Arduino library that are initially built for AVR micros. And so the LCD is driven with SPI … Continue reading

Wrist watch size Enigma machine

If you are WWII enthusiast or simply interested in ciphers then take a look at this great project. Basically this is a replica of famous German Enigma coding machine which fits on a wrist. It is built around Arduino and can be controlled with three buttons. Information is visible in graphical OLED display. User interface is quite well thought and robust. Initially you need to know a bit about setting Enigma wheels to start encoding letters. Custom enclosure and straps looks really firm and durable.

Simple OLED alarm clock with temperature feature

OLED displays have many benefits over regular LCDs. They have better better contrast. Because there are not back-light used, a deep black levels can be displayed. They have wider viewing angles and are more power efficient. Also are more lightweight what makes them attractive for using in hand-held devices. OLED displays are available in hobby market so everyone can use them for great projects and see the benefits. Df99 have shared his instructable where he builds pretty cool alarm clock with temperature display by using Arduino Micro and 128×64 OLED display based on SSD1306 controller. Clock function is implemented with DS3231 RTC IC which has Arduino library support. Clock has two push-buttons for clock setting. Temperature readings are done from RTC chip where sensor is used to compensate temperature drift.