Overview

Firmware for a homemade automated electric armchair.
Extensive details about this project can be found here:

• V1: Electric Armchair V1
• V2: Electric Armchair V2

In the current version V2.2, only the esp-project in the board_single/ folder plus the custom libraries in common/ are used.
Note: The projects in the folders board_control/ and board_motorctl/ are no longer compatible and legacy from V2.1.

Hardware Setup / Electrical

PCB

The firmware in this repository is designed for an ESP32 microcontroller integrated into a custom PCB developed here: Project Work 2020

Connection Plan

A detailed diagram illustrating all components and wiring can be found in the file connection-plan.drawio.pdf

For more details refer to the documentation on the website.

Current Features

• Control Modes:
  • Joystick: Control via hardware joystick mounted on the right armrest
  • HTTP: Control via virtual joystick on a web interface
  • Massage: Armchair shaking depending on stick position
  • Auto: Execute stored driving commands sequentially
• Electric Chair Adjustment: Leg and backrest control via joystick
• Advanced Motor Control: Configurable motor fading (acceleration, deceleration limit), current limit, braking; compatible with different hardware
• Wi-Fi:
  • Hosts wireless network
  • Webserver with webroot in SPIFFS
  • HTTP API for controlling the chair
• UART Communication between 2 boards (V2.1)
• Speed Measurement: Measures speed and direction of each tire individually using custom encoders
• Current Measurement: Monitors current of each motor
• Battery Capacity: Measures battery voltage and calculates percentage according to discharge curve
• Fan Control: Cooling fan for motor driver activated only when needed
• Display:
  • Various status screens showing battery status, speed, RPM, motor current, mode, power, duty cycle, stick data
  • Menu for setting various options using encoder
• Buzzer: Provides acoustic feedback when switching modes or interacting with menu

Planned Features

• More Sensors:
  • Accelerometer
  • Lidar sensor / collision detection
  • GPS receiver
  • Temperature sensors
• Anti-Slip Regulation
• Self-Driving Algorithm
• Lights
• Improved Web Interface
• App
• Camera

Installation

Install esp-idf

For this project ESP-IDF v4.4.4 is required (with other versions it might not compile)

#download esp-idf
yay -S esp-idf #alternatively clone the esp-idf repository from github
#run installation script in installed folder
/opt/esp-idf/install.sh

Clone this repo

git clone git@github.com:Jonny999999/armchair_fw

Instal node packages

For the react app packages have to be installed using npm. TODO: add this to cmake?

cd react-app
npm install

Building the Project

React-webapp

When flashing to the ESP32, the files in the react-app/build/ folder are written to a SPIFFS partition.
These files are then served via HTTP in the Wi-Fi network "armchair" created by the ESP32.
In HTTP control mode, you can control the armchair using a joystick on the provided website.

Initially, or when changing the React code, you need to manually build the React app:

cd react-app
#compile
npm run build
#remove unwanted license file (filename too long for spiffs)
rm build/static/js/main.8f9aec76.js.LICENSE.txt

Note: Use npm start for starting the webapp locally for testing

Firmware

Set up environment

source /opt/esp-idf/export.sh

(run once per terminal)

Compile

cd board_single
idf.py build

Upload

• connect FTDI programmer to board (VCC to VCC; TX to RX; RX to TX)
• press REST and BOOT button
• release RESET button (keep pressing boot)
• run flash command:

idf.py flash

• once "connecting...' was successfully, BOOT button can be released

Monitor

To view log output for debugging, follow the same steps as in the Upload section, but run:

idf.py monitor

Usage / User Interface

Encoder Functions

When not in MENU mode, the button (encoder click) has the following functions:

Count	Type	Action	Description
1x long	switch mode	MENU	Open menu to set various options, controlled via display and rotary encoder.
1x	control	[MASSAGE] freeze input	When in massage mode: lock or unlock joystick input at current position.
1x short, 1x long	switch mode	ADJUST-CHAIR	Switch to mode where the armchair leg and backrest are controlled via joystick.
2x	toggle mode	IDLE <=> previous	Enable/disable chair armchair (e.g., enable after startup or switch to previous mode after timeout).
3x	switch mode	JOYSTICK	Switch to JOYSTICK mode, to control armchair using joystick (default).
4x	switch mode	HTTP	Switch to remote control via web-app http://191.168.4.1 in wifi armchair.
5x
6x	switch mode	MASSAGE	Switch to MASSAGE mode where armchair shakes differently, depending on joystick position.
7x
8x	toggle option	deceleration limit	Disable/enable deceleration limit (default on) => more responsive.
12x	toggle option	alt stick mapping	Toggle between default and alternative stick mapping (reverse direction swapped).

When in MENU mode (1x long press), the encoder controls the menu:

Encoder Event	Current Menu	Action
long press	main-menu	Exit MENU mode to previous control mode (e.g., JOYSTICK).
long press	value-select	Exit to main-menu without changing the value.
click	main-menu	Select currently highlighted menu item -> enter value-select screen.
click	value-select	Confirm value / run action.
rotate	main-menu	Scroll through menu items.
rotate	value-select	Change value.

HTTP Mode

Control the armchair via a virtual joystick on the web interface.

Usage:

• Switch to HTTP mode (4 button presses).
• Connect to WiFi armchar, no password.
• Access http://192.168.4.1 (note: http NOT https, some browsers automatically add https!).