Digital Clock - Part 5

This is part of the Arduino-based Digital Clock series. This post is the fifth post in the series. For the previous post in this series, go to Part 4.

I have replaced the Arduino Nano with Arduino Pro Mini. In my initial setup I just pulled out the Nano, plug in the Pro Mini to a different half length breadboard, and used jumper wires to connect the mini to the original wires from the previous part. For the software side I made no change to the sketch/C++ source code, I only need to instruct that the build target is now Pro Mini instead of Nano.

Considering the original reason to change the Nano to Pro Mini is to reduce the current consumption, I started measuring.

  • At LCD backlight min setting, 21.07mA - 22.83mA.
  • At LCD backlight min setting and alarm triggered, 50.66mA - 51.18mA.
  • At LCD backlight max setting, 40.04mA - 41.69mA.
  • At LCD backlight max setting and alarm triggered, 69.3mA - 69.9mA.

Subjectively the LCD is best viewed with 75% brightness setting, and I measured the consumption as: 22mA - 23.77mA. This will be its typical consumption. So for the typical usage there’s already an improvement compared to Part 4, but very little (reduction of 1.69mA - 1.88mA). Looks like I’ll have to take a look at Arduino Low-Power library next. And maybe to cut off the power LED from the Pro Mini. Meanwhile, I decided to tidy up the rat tails.

No new components are added other than replacing the Nano with Pro Mini. The other notable change is that the LCD contrast and LCD brightness potentiometers are now grouped on top right of the breadboard. Other than that I only make the modules closer to each other and rewirings necessary for that.

See you laters.