# Fifth Lichuang Electronic Design Competition # Native HomeKit air conditioner remote control and multi-sensor

Native HomeKit air conditioner remote control and multi-sensor

Self introduction

Hello everyone, I am Wang Xiaocai, an amateur DIY enthusiast.

Project Introduction

This product is a DIY smart home accessory with functions such as air conditioner infrared remote control, temperature, humidity and light sensor , and supports Apple's native HomeKit protocol .

1. Project details

The main functions of this work are air conditioning remote control, temperature and humidity and light sensing, and supports HomeKit protocol and Web control.

• Native HomeKit accessories : can run independently without any bridge server such as homeassistant or homebridge. This accessory can be added directly to the home APP of iPhone, iPad, Mac, etc., and supports Siri voice control, home automation, multi-device iCloud synchronization, etc.
• Air conditioning control : air conditioning switch, mode, temperature, wind speed, sweep, lighting (digital display), etc., supports dozens of air conditioning infrared protocols
• Sensor : Temperature, humidity and light real-time data, historical curves, export CSV format data document
• Mini size : PCB length and width 3.6x3.6cm, case length and width 3.88x3.88cm and thickness 1.64cm

Note: The accessory implements Apple's public non-commercial versionHomeKit Accessory Protocol (Non-Commercial Version) , see developer.apple.com .

1.1 HomeKit functions

• Add this accessory to the Home APP on iPhone, iPad, Mac and other Apple devices. The pairing code is111-11-111
• Accessories include air conditioners and air conditioner lights, temperature, humidity, lighting
• Supports control of air conditioner switches, modes, temperature, wind speed, sweep, and lighting (digital display)
• Supports real-time updates of temperature, humidity, and light
• Supports Siri voice control, automation, multi-device iCloud synchronization, and remote control

Note: Remote control, automation and other functions require the configuration of a home hub. An iPad, Apple TV or HomePod is required as the home hub. Please refer to the introduction on the Home APP Automation tab page.

1.2 Web functions

• Access http://{ip}the web page and {ip}provide more comprehensive control and functions than HomeKit for the IP address of ESP8266 after it is connected to the Internet.

• Air conditioning: Configure air conditioning infrared protocols and sub-models, supporting advanced air conditioning controls such as silent, powerful, economical, economical, and filtering.

• Sensor: View real-time data, view historical record line charts by day/week/month, and export historical data in CSV format for the past month in File Manager

• Historical data: Sensor historical data is stored in the built-in Flash of ESP8266, based on the SPIFFS file system. It is recorded every 10 minutes and retains historical data within the past 30 days.

• Other functions: View system information, WiFi configuration, internal file browsing, online firmware upgrade

• Support Apple-WebAPP full screen mode: Safari browser->Share->Add to home screen

2. Challenges faced and problems solved

The main goal of this work is to realize native HomeKit accessories. Compared with other smart home solutions, the advantage is that it can be directly connected to the Apple HomeKit smart home system and experience Apple's unified, whole-family-style good smart home experience on iPhone, iPad, and Mac. This accessory can be controlled and used on , Watch.

Apple HomeKit is one of the mature smart home protocols. The HomeKit protocol has been publicly released for many years. For a long time, a bridge server has been commonly used to connect DIY devices to HomeKit, such as homeassistant or homebridge. The cost is high and the configuration is complicated.

I have noticed before that the esp-homekit project on github can realize the ESP8266 to run the HomeKit protocol independently, and can abandon the configuration of the bridge server. The fly in the ointment is that the project is based on the non-Espressif official ESP8266 development SDK. The compilation tool configuration is complicated and it is difficult to get started.

During the epidemic in the first half of this year, I personally transplanted the project to Espressif's official Arduino SDK and released Arduino-HomeKit-ESP8266 , which is compatible with Arduino one-click compilation, lowers the compilation threshold, and provides an easy-to-use method that supports HomeKit in the Arduino environment. plan. In addition, this library is also officially recommended by Espressif as an alternative to implement HomeKit on ESP8266 .

3. Key points of project hardware and software

PCB

• Compact layout : The size is only 3.6x3.6cm, only larger than a one-yuan coin (diameter 2.5cm).

• Omnidirectional full-power infrared emission : The layout refers to the finished universal remote controls of Mijia and Tmall Genie, using seven 5MM transmitting tubes to achieve 360° omnidirectional remote control. Use an N-MOS tube to drive the transmitter tube, and select the current limiting resistor based on the maximum current (100mA) in the transmitter tube data sheet. The actual current is about 92mA. According to actual measurements, omnidirectional coverage can be achieved in a general room. When the transmitter tube faces away from the air conditioner, it relies on wall reflection. It can also be controlled normally.

• High-precision temperature and humidity sensor : Using the SHTC3 high-precision sensor from Sensirion, Switzerland, the accuracy is ±0.2℃ / ±2%RH, the range is -40~125℃ / 0~100%RH. The DFN 4-pin package of the chip is compared to the DFN The 8-pin package SHT3x is relatively easy to solder.

• Digital light sensor : Use BH1750 digital ambient light sensor, supports 0.11lx accuracy, range 1 - 65535 lx, welding is slightly difficult.

• Thermal isolation design : The main heating element ESP8266 and the voltage-reducing chip are located on the right side of the top surface of the PCB. The temperature and humidity chip SHTC3 is located on the left side of the bottom surface of the PCB. In addition, a PCB slot is dug out in SHTC3 to isolate it from other parts to minimize the impact of component heating on temperature and humidity. Sensor effects.

• Burning interface : Using the ESP-01 layout, you can directly connect the ESP-01 burning tool with the onboard automatic burning circuit to achieve one-click burning, or you can use other USB-TTL burning tools for burning.

shell

• Mini size : length and width 3.88x3.88cm, thickness 1.64cm, fixed with 4 M2 screws about 6mm long.

• 3D printing model : can be printed with translucent (natural color) or transparent PLA. In the middle 2 pictures, the upper side is translucent material (PCB is not soldered), and the lower side is transparent material (PCB is soldered). The actual object of translucent material has a more texture, while the actual object of transparent material has a different feeling. There is no need to add support to the top cover, and only the round groove part of the magnet in the bottom cover needs support. The model size is optimized for 0.2mm layer thickness and 0.4mm nozzle.

• Heat dissipation design : The top cover has a large range of heat dissipation openings to enhance heat dissipation, and the bottom SHTC3 is completely exposed to reduce the impact of component heating on the temperature and humidity sensor.

• Magnetic fixation : A 2.5cm diameter magnet (the same size as a 1-yuan coin) can be attached to the back. The accessory can be attached to any iron-containing surface, or double-sided tape can be used to fix it. Omnidirectional full-power infrared emission, magnetic placement is relatively free.

software

• Using my personal open source Arduino-HomeKit-ESP8266 to implement the HomeKit protocol, native HomeKit accessories can be directly implemented.

• Use crankyoldgit's open source IRremoteESP8266 library to implement air conditioner remote control infrared encoding and decoding, supporting dozens of models of air conditioner infrared protocols.

4. Project material list

5. Project pictures

The above is the actual picture of the PCB after welding and the 2D rendering in Lichuang EDA. Both the top and bottom surfaces have the competition logo.

6. Project demonstration video

6.1. Video upload contest official website

uploaded.

6.2. Video title and link at Station B

Self-introduction: The 5th LiChuang Electronics Design Competition: DIY HomeKit air conditioner remote control and multi-sensor - self-introduction

Project Introduction: The 5th Lichuang Electronic Design Competition: DIY HomeKit Air Conditioner Remote Control and Multi-Sensor - Project Introduction

Function Demonstration & Performance Test: The 5th Lichuang Electronic Design Competition: DIY HomeKit Air Conditioner Remote Control and Multi-Sensor - Function Demonstration & Performance Test

7. Whether it is released to the public for the first time

This project is being made public for the first time.

8. Open source documents

The schematic diagram and PCB are completely produced using Lichuang EDA. They are published in this project and can be opened in the editor. See attachments for firmware and shell models.

9. References

Click the link for more details: https://www.szlcsc.com/go/dsxq