This is a great credit card sized business card and gaming console based on Arduino.
The primary trick of this design is having milled cutouts made for surface mount components to be press fit into, using the circuit board as a kind of frame. Components selected have a thickness near that of the circuit board (1.6mm). Furthermore, to minimize the board thickness, the Atmega328P is inverted so that the bulk of its height below the surface. The result of equal thickness and recessed installation provides a flush appearance. The primary benefit beyond the aesthetic quality is the device is easily slid from a wallet. The high quality boards and the excellent service from oshpark also makes this build possible.
Arduboy: The Interactive Digital Business Card - [Link]
This soldering station controls a 24v 50W solder. Based on ATmega328p microcontroller, with combination of IRL3103 or IRFZ44 MOSFET, 5v 0.5A and 24v 3A power supplies,1500uF 35v capacitor, DS1307 – Real Time Clock, MAX7219 – 4 digit 7 segment LED driver, LEDs and other electronic components. Hakko 936 soldering iron handle with thermocouple control. A LM358 amplifies signal from thermocouple with gain 101.
DIY Soldering Station - [Link]
svkatz80 @ fritzing.org build a nice LED clock. He writes:
This clock is based on ATmega328p microcontroller, with combination of DS1307 – Real Time Clock, MAX7219 – 64 LEDs drivers, 74HC595 – shift registers, DS18B20 – temperature sensor, GL5528 – photoresistor, LEDs and other electronic components.
- Clock with RGB seconds — Four 74HC595 control 10 RGB leds. But TLC5940 is a better choice.
- Ellipse clock — Three MAX7219 control all LEDs. No shift registers needed.
Each MAX7219 can control 64 LEDs. For ellipse clock I used tree of them. The first one controls 2 hour’s digits (2x7x4=56 green leds + 6 blue leds + 2 dots between hours and minutes ). The second one controls 2 minute’s digits (2x7x4=56 green leds + 6 blue leds). The third MAX7219 controls second’s 60 red leds .
For making a 7 segment digits, I used 5×7 cm prototype PCB circuit board. Before solder the LEDs, I wired the board for 4 digits and 7 segments each of four boards with copper wire. See circuit.
As a main board I used a coroplast (polygal) sheet. Just print the sketch and make on polygal holes with a needle for LEDs.
ATmega328p based LED wall clock - [Link]
Kerry Wong built a DIY constant current/constant power electronic load. It can sink more than 200W of power:
A while back I built a simple constant current electronic load using an aluminum HDD cooler case as the heatsink. While it was sufficient for a few amps’ load under low voltages, it could not handle load much higher than a few dozen watts at least not for a prolonged period of time. So this time around, I decided to build a much beefier electronic load so it could be used in more demanding situations.
One of the features a lot of commercial electronic loads has in common is the ability to sink constant power. Constant power would come in handy when measuring battery capacities (Wh) or testing power supplies for instance. To accommodate this, I decided to use an Arduino (ATmega328p) microcontroller.
Building a constant current/constant power electronic load - [Link]
Zak Kemble build a digital wristwatch with a 1.3″ 128×64 OLED display & AVR ATmega328P microcontroller:
The main incentive behind this project was to see how much I could cram, in terms of both hardware and software, into a wristwatch-like device that is no larger than the display itself. An OLED display was chosen for being only 1.5mm thick and not requiring a backlight (each pixel produces its own light), but mostly because they look cool. The watch was originally going to have a 0.96″ display, but this proved too difficult to get all the things I wanted underneath it. Going up a size to 1.3″ was perfect.
DIY OLED digital wristwatch - [Link]
Niek designed this BareDuino micro, that is available at github:
For some Arduino projects, you don’t actually need that many IO pins. That’s exactly the case when I tried to build a simple RGB throwie that would cycle through colours. I was looking for a cheaper alternative to the Arduino UNO’s ATmega328P when I stumbled across this post by MIT’s High-Low Tech lab. They developed a library for programming the 8-pins ATtiny45/85 from the Arduino IDE. It’s a very smart solution to use permanently in some low pin-usage projects, but you still need to hook up individual wires from your programmer to the ATtiny to be able to program it. That’s when I came up with the idea of the BareDuino Micro.
BareDuino micro - [Link]
Harrymatic @ instructables.com writes:
I am in the process of designing a function generator and I needed a frequency counter to check it against. This project uses a minimal number of components for a very economical and compact design. A bare-bones Arduino clone is at the heart of this project and the measured frequency is shown on an LCD display. The maximum frequency that this can measure is about 8 MHz (at a 50% duty cycle). Despite the fact that this counts the frequency on one of the digital pins, I have found that it will quite happily measure sine and triangle waves providing that they have a suitable amplitude.
8MHz Frequency Counter - [Link]
Unit is based on Arduino Atmega328P MCU, with over 430 UV LEDs. The PCB board is made using Toner transfer method and isn’t perfect. It was just too big and I was too lazy to do it again. However, marker here, scratch it there and it it good enough.
The unit itself is on single sided copper clad board, no additional cables, no narrow paths (except for one for power on the MCU). Design is straight forward. It’s designed to be powered from 12V source (computer) and take around 2,7Amps @ full power which means around 30Watts.
DIY UV Exposure Unit with LED and Arduino - [Link]
An Arduino-based clock with 180 RGB LEDs. The LEDs are driven via 12 TLC5925 1- channel constant-current addressable drivers – [via]
Its built on doublesided copper clad board using Toner transfer method. The routes aren’t smaller than 0.44mm and all vias are made for 0.8mm drilling (truly DIY). Just around 5 vias are under a component and 7 segment displays have singnals only from bottom side (for easy soldering)
- 180 RGB LEDs driven by TLC5925 constant current LED drivers
- each LED addressed separately (12x TLC5925 with 16 outputs each)
- each colour adressed individually
- 4x 7 segment LED display
- Atmega328P as MCU
- DS1307 real time clock
- Photoresistor (for adjusting brightness)
- And DHT11 for temperature and humidity
- Backup battery for clock
- 5V DC (eg USB)
Clock with 180 RGB LEDs on home-etched circuit board - [Link]