Inspired by Kevin Darrahs video on Low Power Arduino! Deep Sleep Tutorial, I set out to see if I could apply some power saving to the basic blink program.
After the usual trial and error, I did get results. Normal current usage of lit/unlit Arduino nano running blink is 14/12mA. Replacing delay() with my own function going to sleep in power-down mode reduced the current to 6.6/4.6mA.
The power LED is always lit, consuming 2mA. Kevin was running his tests on a breadboard Atmega328P, obviously the Nano has a bunch more circuitry so thats where a bunch of current goes to.
And also, both the Arduino Nano and Arduino UNO will happily run off a 4 volt battery. Just connect + to the 5V rail (not VIN) and – to GND. I was using a battery from a mobile phone (nominal 3.7V but fully charged to 4V).
Source can be found here: PowerBlink.ino
From a post on /r/Arduino I had some ideas about how to make a simple wind sensor.
Tested one of the Hall sensors I have with a neodymium magnet I took out of an old CD-ROM. The particular Hall sensor in the breakout board is a 49E501BG. At first I tried another Hall sensor but the output from that one was almost digital, useless.
When I tested it I attached the magnet to the tip of a screwdriver and moved it around in all kinds of ways around the sensor. It gave nice clear readings from 300 with the magnet at its closest to 600 with no magnet or even 800 if the reverse side of the magnet was close.
Pingpong ball would give the wind more to drag on. A dampener (more rubber bands) would be good so that the magnet doesnt move too far away even in a full storm.
Received package from China yesterday. Went through all the goodies quickly and my attention stopped at the 32×8 LED matrix. Worked on it the rest of the evening, got it powered up and figured out how to light individual LEDs just before it was bedtime.
This morning I continued with the Arduino programming and by noon I had the result I was aiming for, for now.
“Happy new year 2017!!!”
Delivery arrived from China. Order placed on November 30, 2016.