A reference design for an Arduino UNO compatible board based on the FTDI FT231X USB UART, delivers 5V at a full 1A without overheating.
This project started out as an accessory for another planned KickStarter project – a smart TFT display for Arduino called CleO. Now, the display itself required 150mA current, fine, but when you add a camera with its LED lights, this goes up to 250mA and if you have 1W audio playing simultaneously, unlikely,but possible, then it would require 450mA of current at 5V in order to guarantee operation. You could the USB jack to supply 500mA power, but this doesn’t leave much headroom to power other Arduino shields, so connecting a PSU to the DC jack seemed to be the answer. This started us thinking – well, the LDO regulator on an UNO and compatible boards is rated at 1A **but** how much current can you actually take without the regulator overheating and shutting down. We decided to measure it on a genuine UNO R3 board at 9V and 12V input, and the answer was surprisingly low especially with a 12V supply. Our measurements and test methodology are shared with you below.
The UNO R3 is the staple of most Arduino based projects but it’s been around for a number of years and many of the features have been improved for example by Adafruit and Sparkfun who make excellent enhanced UNO compatibles. However, our additional requirements for a full 1A current without excess heat dissipation and FCC/CE conformity led us to consider a new 3rd party UNO compatible reference design that met these requirements hence the inspiration behind NerO. We were delighted with the results of our prototype so we decided to make it available in its own right for anyone to use. On launch we will make the NerO schematic and pcb design files available publicly as a reference design under OSHWA ( Open Source Hardware Association ) terms and welcome the community to benefit from our original design work.
NerO – An Energy Efficient Arduino UNO Compatible Design – [Link]