ARIZON USB APIServer

An APIServer for ARIZON USB force sensors.

Installation

Clone & cd into this repository then:

python setup.py install

Or download from PyPI:

python -m pip install arizon-usb-apiserver

Get Started

The apiserver operates in two modes: RESTful and gRPC. They share the same configuration schema.

Basics

To read the sensor locally, use this snippet:

from serial import Serial
from arizon_usb_apiserver import Sensor

if __name__ == '__main__':
    conn = Serial("COM16", 115200)
    sensor = Sensor(conn)
    sensor.reset()
    while True:
        print(sensor.read_once())

To generate configuration from command line interaction run:

python -m arizon_usb_apiserver configure

RESTful

To launch the apiserver in RESTful mode, set the API_SERVER_RESTFUL to 1 before run apiserver command:

export API_SERVER_RESTFUL=1

Or run with variable

API_SERVER_RESTFUL=1 python -m arizon_usb_apiserver apiserver

Powershell: Set-Item -Path Env:API_SERVER_RESTFUL -Value 1

Or you can directely run apiserver.restful

python -m arizon_usb_apiserver apiserver.restful

Here are some examples to test the apiserver using curl

• Init sensor

  curl -X 'PUT' \
    'http://127.0.0.1:8080/v1/arizon/force?flag=true' \
    -H 'accept: application/json'

• Read sensor

  curl -X 'GET' \
    'http://127.0.0.1:8080/v1/arizon/force' \
    -H 'accept: application/json'

• Shutdown sensor

  curl -X 'PUT' \
    'http://127.0.0.1:8080/v1/arizon/force?flag=false' \
    -H 'accept: application/json'

gRPC

Run this command

python -m arizon_usb_apiserver apiserver

Or you can directely run apiserver.grpc

python -m arizon_usb_apiserver apiserver.grpc

Testing with cli tools

To test RESTful API, run:

python -m arizon_usb_apiserver test.restful

You will be asked to input API endpoint.

To test gRPC API, run:

python -m arizon_usb_apiserver test.grpc

You will be asked to input API endpoint.

Generate Client

Restful

First launch the apiserver, then run openapi-python-client:

openapi-python-client generate --url http://127.0.0.1:8080/openapi.json
rm -rf ./arizon_usb_driver/client/restful
mv fast-api-client/fast_api_client ./arizon_usb_driver/client/restful
rm -rf ./fast-api-client

GRPC

First cd arizon_usb_apiserver/grpc, then run:

python -m grpc_tools.protoc -I../../manifests/protos --python_out=. --pyi_out=. --grpc_python_out=. ../../manifests/protos/force_packet.proto

You might need to replace import force_packet_pb2 as force__packet__pb2 with import arizon_usb_apiserver.grpc.force_packet_pb2 as force__packet__pb2

Serial Protocol

Field	Content
Head	0xFE
Status	1 Byte
Data	3 Byte
XOR checksum	1 Byte

• Status: 4 bits of address + 4 bits represents number of digits
• Data: 3 bytes of signed integers, no digit, big-endian.
• Checksum: xor() of first 5 bytes

Configuration

Here is an template of configuration

arizon_usb_apiserver: # Key
  api: # Control API settings
    interface: 0.0.0.0 # Listen interface
    port: 8080 # Listen port
  debug: false # Enable debug
  serials: # Serial connections, can be a list
    - baudrate: 115200 # Baudrate, default is 115200, no need to change
      port: COM8 # Port name
      addr: "dev1" # Friendly name
  data_path: ./arizon_data # Path to save data