There is always a dilemma on how to build an indicator for your next project. There are many options like LCDs, LEDs, VFD. Sometimes one or another is enough, but eventually you want something eye catching and obvious that could be seen from distance. For instance for water meter a dial based display probably is better than LCD. IT can be seen from distance and is informative to tell how mutch water is in tank.
John simply built a LED ring display out of 16 single color LEDs. He needed to use shift register, but he thought that popular 74xx595 chip is very current limited. Total current draw shouldn’t exceed 50mA which is like 2 more powerful LEDs at a time. So he looked for more proper shift register and came op with better one – TLC59282 16-bit shift register which is capable of sinking 30mA on each pin. Neat feature of this chip is that it comes with current setting pin, meaning that you only need single resistor for setting current for all LEDs. This saves space on the board. He wrote a nice demo for PIC microcontroller which goes through several display effects. Once you’ve done playing you can use code snippets for displaying info on it like water level, RPM, speed or what ever you want.