Tiny RGB LED cube

RGB LED cube

LED cubes are cheap and great approach to 3D visualization. All you need is a hand full of single color or RGB LEDs and microcontroller. We’ve seen lots of interesting projects that use standard through hole LEDs that already have legs allowing to solder a cube grid. But there are not to many attempts to build cube with SMT LEDs especially with RGB. Hari Wiguna decided to build a tiny RGB LED cube as a module which could be driven by microcontroller platforms like Arduino. Since RGB LEDs are already three LEDs packed in, he build 4x4x4 configuration which already require 64 LEDs. If we count individual diodes there are 192 of them. So controlling them all already is some task. The size of cube is also tiny – cross cut is same size as quarter coin. When you squeeze the cube you very quickly loose the 3D effect, since diodes start masking each other. In this case I think this limit is quite reached, because SMT RBG LEDs aren’t transparent. Anyway it still allows creating lots of great effects.… Continue reading

Arduino based non contact infrared thermometer

Arduino infrared thermometer

In some cases you might want to measure temperature without touching object. One solution is to use infrared thermometer. You’ve probably seen one somewhere in hospital where nurses usually measure temperature of patient from distance. Educ8s.tv has been sponsored with couple parts needed to build a simple infrared thermometer. The key element here is MLX90614 IR temperature sensor, which has pretty good characteristics: measured temperature range from -70 to 380ºC accuracy of 0.5ºC (when measured between 0 and 50ºC) resolution of 0.02ºC IIC digital interface small size He built thermometer by using Arduino and Nokia 5110 LCD shield. Fun fact is if you point thermometer to your body it will show much lower temperature than it is inside body. Simple explanation to this is that skin temperature is lower ~ 32ºC while normal body temperature is 36.6ºC. You should calibrate thermometer before measuring actual body temperature. You could use such infrared thermometer in many interesting projects like scanning thermovisor, inspecting temperature of home appliances, live stock, green house monitoring, movement detection, thermal relays and more. Continue reading

Nixie tube based digital thermometer

It is always handy to have few digital thermometers around the house. You may want continuously monitor indoor and outdoor temperatures, Use it for specific needs, for instance when preparing food or regulating boiler water temperature. If you would like to check digital thermometer value from a distance, then you should go with bright display. You can always use large bright LED seven segment displays, but if you have few spare nixie tubes around, why not use them instead. Luca Dentella have build three digit Nixie tube digital thermometer based on Arduino. He has chosen 10K thermistor based temperature sensor which can be easily read through Arduino analog input. He wanted nixies to look even cooler, so he added RGB LEDs with WS2812 control chips underneath each tube. This way he could get cool effects by adjusting background color according to temperature values. Lately he completed his project by assembling thermometer on PCB he received. Only one thing that is still missing is enclosure. Continue reading

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 64×48 Lcd display. He soldered all components on prototyping board and put in to 3D printed enclosure with display, bulb sensor connector, power plug and control button. With his meter he was able to take pretty interesting measurements including cooling maps taken from cooling fan area with 2mm resolution. Continue reading

Displaying analog signals on TFT LCD display with Arduino


If you want to see analog or digital signals there is always an oscilloscope where you can choose various parameters (scale, time). But if you are building a project where you only need constantly to monitor some known signals like audio or sensor data, then oscilloscope would be an overkill. Why not to include TFT LCD display module to your project and have visual feedback on what’s going on. dmainmon in his instructable have shared his demo where he used Arduino Mega 2560 R3 and 2.8” TFT LCD display to display the analog signals of your choice. In his demonstration he used couple signal sources: light sensor and audio sensor. The graphs simply compile on LCD display continuously. He implemented simple touchscreen menu where he can select some properties on how those graphs are displayed. He can select graph color and sweep direction. Continue reading

Universal Arduino based distance meter

One way to measure the distance is to use ultrasonic transducer which is cheap and robust. Paoson Woodwork constantly needs to measure distances inside room while installing furniture or doing repair work. So he came up with idea of building an universal distance meter which would measure distances in all four directions at once. He put electronics in to his custom made plywood enclosure where he made openings for sr04 ultrasonic transducers. He put an LCD in front, along with two buttons for unit selection and function. Additionally there is a bubble level tube included to keep things straight when hanging on the wall. All you have to do is to hang the meter on the wall and it displays the distance on LCD for in all four directions. It can display the area of wall with a single button press. There are other programs available along with area and distance. These are Rel – to measure relative distance, Total – to measure total distance between two opposing surfaces. Continue reading