design.md

layout	design
title	Design
permalink	/design
sequence	5
items	name url height width depth dimension_unit weight weight_unit comment Battery holder for 3AA https://docs-apac.rs-online.com/webdocs/1659/0900766b81659aed.pdf 57.7 47 16.6 mm 9.4 g enclosure
sub_system	true
state_machine	true
terminologies	term definition Device Pine, the entire electronics with embedded firmware and associated software term definition Ideal temperature Desired room temperature as configured by the first-time user term definition Power on A DPST switch to power on the entire device term definition Power off A DPST switch to power off the entire device term definition Start button A push button to start the device function every interval for a duration of time term definition ON command Array of raw IR code to turn on the aircon at a certain temperature term definition OFF command Array of raw IR code to turn off the aircon term definition Interval Time period after which the device will check for room temperature and turn on or off the aircon E.g. 30 minutes term definition Duration Length of total time during which the device will start functioning and then stop until it is started again term definition Ideal temperature Desired room temperature as configured by the first-time user
user_stories	user actions first-time user goal reason save the ON command of the aircon remote controller it can be stored and replayed goal reason save the OFF command of the aircon remote controller it can be stored and replayed goal reason configure the interval time for checking the room temperature it can wakeup periodically to check the temperature goal reason configure the total period of time when the device should be checking the temperature it can stop checking the temperature to regulate the room environment after a while goal reason configure the ideal room temperature it can turn ON/OFF the aircon according to the measured temperature user actions user goal reason turn ON the device with an on-board button it can measure the current temperature and turn ON/OFF the aircon periodically goal reason turn OFF the device with an on-board button it can measure the current temperature and turn ON/OFF the aircon periodically goal reason replace the battery the device can be powered again goal reason turn ON the aircon automatically the room becomes cooler towards my ideal temperature goal reason turn OFF the aircon automatically the room becomes warmer towards my ideal temperature goal reason place the device on a vertical surface in line of sight with the aircon it can send the ON command to the aircon goal reason know whether the room temperature is colder or warmer than the ideal temperature through an on-board LED it can send the OFF command to the aircon
features	name Store 2 arrays of about 300 elements of 12-bit integer for raw IR code name Flash in a program with sufficient memory containing IRLib2 with both IR emitter and receiver, compression algorithm. <code> Sketch uses 5476 bytes (16%) of program storage space. Maximum is 32256 bytes. Global variables use 2156 bytes (105%) of dynamic memory, leaving -108 bytes for local variables. Maximum is 2048 bytes.</code> Not enough memory; see <a href="https://www.arduino.cc/en/Guide/Troubleshooting#size">Troubleshooting Guide</a> for tips on reducing your footprint. name Sleep and wakeup periodically with a timer name Support Web USB protocol name Support I2C protocol for temperature sensor
comparison	title samd21 atmega328p Arduino board <a href="https://store.arduino.cc/usa/arduino-mkrzero">Arduino Mkr Zero</a> <a href="https://store.arduino.cc/usa/arduino-uno-rev3">Arduino UNO Rev3</a> title samd21 atmega328p Flash (usage) 256 kB Flash (program and config) 32 kB Flash (program) title samd21 atmega328p EEPROM (usage) no EEPROM 1 kB EEPROM (config) title samd21 atmega328p RAM (usage) 32KB (variables) 2KB (variables) title samd21 RTC 32-bit title samd21 Sleep modes IDLE / STANDBY (<a href="https://www.electrokit.com/uploads/productfile/41014/Atmel-42181-SAM-D21_Datasheet.pdf">Section 18.6.8 Sleep Mode Operation</a>) title samd21 USB USB 2.0 host and device interface title samd21 atmega328p I2C true true

Required features

{% for f in page.features %}
1. {{ f.name }}
{% endfor %}

Aircon compatibility for IR protocols

Options for both supported and unsupported IR protocols are available.

• Supported protocols: Check IRLib2 supported protocols
• Unsupported protocols: Record the IR raw code.
• Example of unsupported protocols: Mitsubishi Aircon remote

SAMD21 vs ATmega328p

{% for chip in page.comparison %} {% endfor %}

	SAMD21	ATmega328p
{{ chip.title }}	{{ chip.samd21 }}	{{ chip.atmega328p }}