Engineering, Gardening

Smart Gardening #5: LCD Display

Now, it is time to program a LCD display with Arduino Micro. This can be used to monitor sensor data (Sensor information), date and weather.

LCD Display.png

Components used in this post

LCD device and programming reference: Sunfounder Wikipage

This LCD has 4 lines (rows) and 20 characters (columns).

Each character position is set by lcd.setCursor(row, column)

We can use a lcd.print(“”) function to print out a message.

If we want to print out a mixture of characters and variables (ex: numbers), lcd.println(variable, DEC) can be called.

Live Demo of LCD Display showing elapsed time

For time and date information, a real time clock (RTC) or GPS module can be used.

Next, start programming a sensor module.

Engineering, Gardening

Smart Gardening #4: Power on 1st prototype board

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!

smart_gardening_prototype_ver1.png

Recap from last time:

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

arduino_micro_spec
Arduino Micro Specification

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
Engineering, Gardening

Smart Gardening #3: Wiring with microcontroller on Prototype Board

Now is time to connect all sensors. Let’s get hands dirty and start soldering on prototype board.

Recap from last time:

Smart Gardening #2: Concept Design by drawing Block Diagram

Components:

uC_and_sensors.png

  1. Define Arduino Micro Pinout

arduino_micro_pinout_ver1.PNG

2. LCD Display to microcontroller

3. Light Sensor Module

4. Moisture Sensor

5. Pressure, Temp + Humidity Sensor

6. Prototype Board

Soldering:

Soldering Tips

  • I like using un-used resistors to run wires on prototype board because I can hold it with the resistor while soldering – wire gets hot!!!
  • When soldering male headers, use 2-pin jumpers to hold it to avoid heat.
img_4668
Running 5V Power Rail horizontally through Arduino pins
img_4669
Wiring and Soldering completed
img_4670
Back side of Prototype Board – took about 1 hour of soldering

Next steps

  • Time to hook up with PC and power on
  • Start Programming and test the sensors individually