MVHR Bypass

IOT device able to control the MVHR Summer Bypass based on inside and outside temperatures.

Compilation

Both the mvhr-bypass-arduino and the mvhr-bypass-esp8266 projects can be edited and compiled with VSCode, which needs the Arduino IDE installed and the following VSCode plugins:

• Arduino
• C/C++

Dependencies and versions

Check the release notes for each MVHR Bypass repo for the latest dependency versions known to work with that specific release.

In addition, the mvhr-bypass-arduino project relies on the TFT_ILI9163 library, which is included as a git submodule.

The mvhr-bypass-common repository contains code which is shared by both mvhr-bypass-arduino and mvhr-bypass-esp8266 and is included in those repos as a git submodule.

Software version compatibility

Add a new entry every time a new version is released. New releases go on top.

mvhr-bypass-arduino	TFT_ILI9163	mvhr-bypass-esp8266	mvhr-bypass-common	mvhr-bypass-android
1.0.0	1.0.0	1.0.0	1.0.0	1.0.0

Flashing software updates on ATmega328p

Available options:

1. Flashing with a USB to Serial converter

2. Using an Arduino board as an ISP:

   • Write the ArduinoISP sketch which is included with Arduino IDE (located in File -> Examples -> ArduinoISP)

   • Hook up the Arduino Uno to the ATmega328p (Double check the sketch in case these change in future versions):

   Arduino Uno Pin	ATmega328p Pin
   D10	RST
   D11	D11
   D12	D12
   D13	D13

   • In VSCode, select the Arduino as ISP programmer and then run the Arduino: Upload Using Programmer command.

Flashing software updates on ESP8266

Available options:

1. OTA Update:

   • Have the PC connected to the same network as ESP8266
   • In VSCode, in arduino.json, set the port value to the current IP address of the ESP8266
   • Upload

2. Direct Serial Flashing:

   • On the Arduino board, hook up the RST pin to GND (this bypasses the onboard microcontroller so you can use just the built in USB to Serial functionality)

   • Remove the two header jumpers that allow the ESP8266 and the ATmega328p to communicate through serial

   • Hook up the Arduino board to the ESP8266:

     Arduino Pin	ESP8266 Pin
     RX	RX (through the voltage divider)
     TX	TX

   • Get the ESP8266 in Program Mode:

     • Press and hold the ESP RST micro-switch
     • Press and hold the ESP PROG micro-switch
     • Release the ESP RST micro-switch
     • Release the ESP PROG micro-switch

   • In VSCode, select the appropriate Serial port

   • Upload

   • Press the ESP RST micro-switch to reset to normal mode

Receiving serial messages for debugging purposes

• On the Arduino board, hook up the RST pin to GND

• For the ATmega328p, hook up:

  Arduino Pin	ATmega328p Pin
  TX	TX

• For the ESP8266, hook up:

  Arduino Pin	ESP8266 Pin
  TX	Serial1 TX

• Open the Serial Monitor and set the baud rate to 9600 bps

Hardware

• 1x 2 pin screw connector
• 1x 6 pin screw connector (or 2x 3 pin)
• 1x AMS1117 module (3.3 V)
• 1x 10 µF capacitor
• 1x ATmega328P-PU
• 2x 22 pF capacitors
• 1x 16 MHz crystal
• 1x ESP8266-01 (labeled "AI-Cloud inside")
• 5x push buttons (4 pin)
• 2x micro-switches (2 pin)
• 2x header jumpers (2 pin)
• 11x header pins
• 1x ILI9163 1.8" SPI TFT 128*160 (labeled "KMR-1.8 SPI")
• 1x 47 Ω resistor
• 1x 1 kΩ resistor
• 1x 2 kΩ resistor
• 9x 2.2 kΩ resistor
• 5x 3.3 kΩ resistor
• 1x 4.7 kΩ resistor
• 5x 10 kΩ resistor
• 1x Relay (5 V)
• 4x DS18B20 Temperature sensors

PCB

Wiring