Smart Prosthesis

The project simplifies the customization and configuration of smart prosthetic hands for diverse user’s needs. Provides a platform that enables the customization of smart prosthetic hands.

Table of Contents

• 1   overview
  • 1.1   System flow
    • 1.1.1   Configuration
    • 1.1.2   Operation
  • 1.2   Class Diagram
• 2   Admin (user) Instructions
  • 2.1   YAML sctucture
  • 2.2   Sending Configs
  • 2.3   Sensors Activity
• 3   Developer Instructions
  • 3.1   Write A Hand Function
  • 3.2   Sending Data Via Wi-Fi
  • 3.3   Sending Data Via BLE
• 4   Poster

1   overview

1.1   System flow

The flow can be divided into two main parts: configuration and operation.

1.1.1   Configuration

The configuration of the hand consists of two main parts:

1. YAML file -

   The system either loads from memory or receives from the user a YAML file that specifies the system components. This allows for full flexibility in modifying the hand structure in the future. The YAML file also associates sensors with their target functionalities (see functionality).

   After receiving a new configuration file from the user, it will be saved to memory and loaded the next time the controller is launched.

   Example for such YAML file:

   

2. Functionality -

   Each sensor corresponds to a specific function that defines the desired behavior of the hand based on the values sensed by the sensor.

   These functions are pre-written by the administrator and can be easily added or modified as needed. Each sensor's functionality should be specified in the YAML file.

note The configuration of the hand is a one-time operation and does not need to be repeated each time the hand is relaunched.

1.1.2   Operation

After the hand is configured, the system operates with three main flows, managed by three threads:

1. BLE + WIFI listenner:

   This thread listens for asynchronous interrupts. once caught an interrupt - creates a new command object which allows the communication with the third thread. A new command is labeled with a "pending" flag to be executed by the third thread (described below).

2. HW management:

   This is the only thread that writes to and reads from HW.

   Commands received from sensors are translated into basic motor actions and stored as the current "state." Each state has an "end condition" (i.e., the current value sensed by the motor). The HW Management thread iterates through all motors, checks their states, and directs the motors to start an action (with custom direction and speed), stop an action, or make no change to their operation.

3. Process payload and manage logic:

   This thread is responsible for parsing payloads received from sensors and triggering the relevant hand functions. These functions update the motor states used for communication with the HW Management thread, which controls the motors.

note: The threads communicate with shared resources, protected and synchronized with locks.

1.2   Class Diagram

2   Admin (user) Instructions

This section covers:

1. Writing a New Configuration File (YAML): YAML structure
2. Sending a New Configuration (YAML) to the Hand: sending configs
3. Getting Data About Connected Sensors: sensors activity

2.1   YAML sctucture

The YAML file should start with a file type field set to config_system. The YAML consists of two main parts:

1. Inputs (Sensors): Attributes include name, id, type, and function (the corresponding hand function pre-coded by the admin).
2. Outputs (Motors): Attributes include name, type, and pins.

An example YAML file is provided in this repository under the name config_system_usecase.yaml (or see YAML_FIGURE above).

2.2   Sending Configs

When the hand (controller) is powered on, it acts as a Wi-Fi access point, creating a small LAN for communication. To send your YAML file:

1. Connect to the hand's Wi-Fi network from your PC. Look for "smart_prosthesis" and enter the password: "100inIOT".
2. Open a web browser and navigate to "192.168.4.1" (the default IP address of the controller).
3. a text box will appear; paste your YAML file or modify the default configuration and click 'Send'.

2.3   Sensors Activity

Connect to the hand's Wi-Fi network as described above and access the page at 192.168.4.1/sensors_activity.

3   Developer Instructions

This section covers:

1. Writing New Hand Functions: write hand function
2. Sending Data Via Wi-Fi:
3. Sending Data Via BLE:

3.1   Write A Hand Function

Hand functions are defined and implemented in ./main/hand_functions.ino. The API for accessing hand elements (motors, sensors, etc.) can be found in ./main/classes.h. Example for accessing a parameter defined in the YAML:

To access param1: 100 (from the YAML file), use params["param1"] in your function. For more details, see the examples in ./main/hand_functions.ino. (For more info see the examples in './main/hand_functions.ino')

note: After adding a new function, add it to the `func_map` defined in `./main/hand_functions.ino`.

3.2   Sending Data Via Wi-Fi

There are 2 ways to send data via wifi:

1. Regular client - wifi client that connects to the hand controller LAN, see wifi client example in './WIFI_client/WIFI_client.ino' note the controller expects to get the payload as a string, which the first byte is the sensor id, followed by the values. we supply the function for converting the payload from uint8_t to string and sending it to the wifi server (controller) - 'send_sensor_values' at './WIFI_client/WIFI_client.ino'.
2. Web page - for easier debug, we support sending a simulated sensor values through a web page. Connect to the hand wifi and enter '192.168.4.1/send_command'

An image of the web page for sending commands:

3.3   Sending Data Via BLE

We support sending data via a BLE terminal (e.g., the BLE Scanner app). The device name for the BLE is 'smart_prosthesis'. The UUID for sending the payload is 'e0198002-7544-42c1-0001-b24344b6aa70'. Note: Due to BLE limitations, we currently support sending payloads up to 20 bytes.

4   Poster