Prototype Highlight:
Powered on prototype board successfully from USB power. LCD display was powered on at 5V. The light sensor has LED indicators showing power GOOD. Using a multimeter, measured 5V power pins on the prototype board and everything is okay so far.
Next step is start programming with Arduino!
Recap from last time:
- Smart Gardening #3: Wiring with microcontroller on Prototype Board
- Smart Gardening #2: Concept Design by drawing Block Diagram
- Smart Gardening #1: Study Data Science in Analog Way
Detailed Progress:
Arduino micro has operating voltage at 5V. I like this because most LCD displays need 5V not 3.3V. Te DC current per IO pin is 20mA at 5V and 50mA at 3.3V, which is adequate for most sensors. Reference: https://store.arduino.cc/usa/arduino-micro

Today, I just powered on the prototype board ver 1 by a microUSB cable connected to a Desktop PC. The multimeter showed 4.96V on one of the sensor power supply pin. This is because there is a on-board voltage regulator on Arduino micro board and the 5V pin may not be exactly 5V due to dropout voltage. If the dropout voltage was too big, this may cause the Arudino and other sensors unstable. So far, it doesn’t seem to be a problem.
Next Steps:
- Start using Arudino IDE on Windows PC
- Programming Arduino for LCD Display first