Python Library for reTerminal

This is a Python library which enables you to use the onboard hardware on the reTerminal and reTerminal Bridge. Currently the accelerometer, user LEDs, user buttons and buzzer can be accessed using this Python library on reTerminal, and the fan, RS232, RS485, CAN can be accessed by using this Python library on reTerminal Bridge.

Installation

From PyPI

• To install the latest release from PyPI

  sudo pip3 install seeed-python-reterminal

From Source

• To install from source, clone this repository

  git clone https://github.com/Seeed-Studio/Seeed_Python_ReTerminal

• Install the library

cd Seeed_Python_ReTerminal
sudo pip3 install .

Usage

User LEDs Test

import seeed_python_reterminal.core as rt
import time

print("STA ON, USR OFF")
rt.sta_led = True
rt.usr_led = False
time.sleep(1)

print("STA OFF, USR ON")
rt.sta_led = False
rt.usr_led = True
time.sleep(1)

print("STA RED, USR OFF")
rt.sta_led_green = False
rt.sta_led_red = True
rt.usr_led = False
time.sleep(1)

print("STA OFF, USR OFF")
rt.sta_led = False
rt.usr_led = False

Buzzer Test

import seeed_python_reterminal.core as rt
import time

print("BUZZER ON")
rt.buzzer = True
time.sleep(1)

print("BUZZER OFF")
rt.buzzer = False

User Buttons Test

import seeed_python_reterminal.core as rt
import seeed_python_reterminal.button as rt_btn

device = rt.get_button_device()
while True:
    for event in device.read_loop():
        buttonEvent = rt_btn.ButtonEvent(event)
        if buttonEvent.name != None:
            print(f"name={str(buttonEvent.name)} value={buttonEvent.value}")

Accelerometer Test

import seeed_python_reterminal.core as rt
import seeed_python_reterminal.acceleration as rt_accel

device = rt.get_acceleration_device()
while True:
    for event in device.read_loop():
        accelEvent = rt_accel.AccelerationEvent(event)
        if accelEvent.name != None:
            print(f"name={str(accelEvent.name)} value={accelEvent.value}")

Accelerometer and Buttons Test

import asyncio
import seeed_python_reterminal.core as rt
import seeed_python_reterminal.acceleration as rt_accel
import seeed_python_reterminal.button as rt_btn

async def accel_coroutine(device):
    async for event in device.async_read_loop():
        accelEvent = rt_accel.AccelerationEvent(event)
        if accelEvent.name != None:
            print(f"accel name={str(accelEvent.name)} value={accelEvent.value}")

async def btn_coroutine(device):
    async for event in device.async_read_loop():
        buttonEvent = rt_btn.ButtonEvent(event)
        if buttonEvent.name != None:
            print(f"name={str(buttonEvent.name)} value={buttonEvent.value}")

accel_device = rt.get_acceleration_device()
btn_device = rt.get_button_device()

asyncio.ensure_future(accel_coroutine(accel_device))
asyncio.ensure_future(btn_coroutine(btn_device))

loop = asyncio.get_event_loop()
loop.run_forever()

Illuminance Sensor Test

import time
import seeed_python_reterminal.core as rt

while True:
    print(rt.illuminance)
    time.sleep(0.2)

The Following Test Should Work With Reterminal Bridge

fan Test

import seeed_python_reterminal.core as rt
import time

print("FAN ON")
rt.fan = True
time.sleep(1)

print("FAN OFF")
rt.fan = False

RS232 Test

import sys
import serial
import time
import seeed_python_reterminal.core as rt

param1 = sys.argv[1]

# enable the rs232 for test
rt.rs232_or_rs485 = "RS232"

# init the serial
ser = serial.Serial(
    port='/dev/ttyS0',
    baudrate = 9600,
    parity=serial.PARITY_NONE,
    stopbits=serial.STOPBITS_ONE,
    bytesize=serial.EIGHTBITS,
    timeout=1
)

if param1 == "send":
    counter=0
    try:
        print("rs232 starts now!\n")
        ser.write("rs232 starts now!\n".encode())
        while 1:
                ser.write(("Write counter:{}\n".format(counter)).encode())
                time.sleep(1)
                counter += 1
    except KeyboardInterrupt:
        exit()
elif param1 == "receive":
    try:
        print("Start receiving data now!\n")
        while 1:
            x=ser.readline()
            if x != b'':
                print(x)
    except KeyboardInterrupt:
        exit()
else:
    print('param input error,try again with send or receive')

Note::When we use the test script of RS232/RS485/CAN.We need to pass a parameter to them.

Take the RS232 for example:

python3 test_rs232.py send # test the send(TX) function of RS232
python3 test_rs232.py receive # test the receive(RX) function of RS232

RS485 Test

import sys
import serial
import time
import seeed_python_reterminal.core as rt

param1 = sys.argv[1]

# enable the rs485 for test
rt.rs232_or_rs485 = "RS485"

# init the serial
ser = serial.Serial(
    port='/dev/ttyS0',
    baudrate = 9600,
    parity=serial.PARITY_NONE,
    stopbits=serial.STOPBITS_ONE,
    bytesize=serial.EIGHTBITS,
    timeout=1
)

if param1 == "send":
    counter=0
    # enable the rs485 for tx
    rt.rs485_tx_rx_stat = "TX"
    try:
        print("rs485 starts now!\n")
        ser.write("rs485 starts now!\n".encode())
        while 1:
                ser.write(("Write counter:{}\n".format(counter)).encode())
                time.sleep(1)
                counter += 1
    except KeyboardInterrupt:
        exit()
elif param1 == "receive":
    # enable the rs485 for rx
    rt.rs485_tx_rx_stat = "RX"
    try:
        print("Start receiving data now!\n")
        while 1:
            x=ser.readline()
            if x != b'':
                print(x)
    except KeyboardInterrupt:
        exit()
else:
    print('param input error,try again with send or receive')

CAN Test

# NOTICE: please make sure you have pip3 install python-can
#         before you use this test script
# import the library
import can
import sys
import time

param1 = sys.argv[1]

# create a bus instance
# many other interfaces are supported as well (see documentation)
bus = can.Bus(interface='socketcan',
              channel='can0',
              receive_own_messages=True)

if param1 == "send":
    # send a message
    counter=0
    print("can send starts now!\n")
    try:
        while True:
            message = can.Message(arbitration_id=123, is_extended_id=True,
                      data=[0x11, 0x22, counter])
            bus.send(message, timeout=0.2)
            time.sleep(1)
            counter += 1
    except KeyboardInterrupt:
        exit()

elif param1 == "receive":
    # iterate over received messages
    try:
        for msg in bus:
            print(f"{msg.arbitration_id:X}: {msg.data}")
    except KeyboardInterrupt:
        exit()
else:
    print('param input error,try again with send or receive')

Note: Please make sure your CAN interface is working before run this script. If not. You will get the error log with "Network is down". And you can enable the can with "sudo ip link set can0 up type can bitrate 500000".

API Reference

• usr_led: Turn on/off green USR LED

rt.usr_led = True #Turn on green USR LED
rt.usr_led = False #Turn off green USR LED

• sta_led_red: Turn on/off red STA LED

rt.sta_led_red = True #Turn on red STA LED
rt.sta_led_red = False #Turn off red STA LED

• sta_led_green: Turn on/off green STA LED

rt.sta_led_green = True #Turn on green STA LED
rt.sta_led_green = False #Turn off green STA LED

Note: If red STA LED is on during this time, the green STA LED will turn on over the red STA LED

• sta_led: Turn on/off green STA LED

rt.sta_led = True #Turn on green STA LED
rt.sta_led = False #Turn off green STA LED

Note: If red STA LED is on during this time, the green STA LED will turn on and the red STA LED will turn off

• buzzer : Turn on/off buzzer

rt.buzzer = True #Turn on buzzer
rt.buzzer = False #Turn off buzzer

• get_button_device(): Obtain information about the buttons including all the events supported by them

device = rt.get_button_device()

• ButtonEvent(): Calls the ButtonEvent() and returns the EVENT

buttonEvent = rt_btn.ButtonEvent(event)

• get_acceleration_device(): Obtain information about the accelerometer including all the events supported by it

device = rt.get_acceleration_device()

• AccelerationEvent(): Calls the AccelerationEvent() and returns the EVENT

accelEvent = rt_accel.AccelerationEvent(event)

• Illuminance :Obtain the current value from the illuminance sensor

  illuminance = rt.illuminance

• fan: Turn on/off fan

rt.fan = True # Turn on fan
rt.fan = False # Turn off fan

• rs232_or_rs485: Open the RS232 or RS485

rt.rs232_or_rs485 = "RS232" # open the RS232
rt.rs232_or_rs485 = "RS485" # open the RS485

• rs485_tx_rx_stat: Switch the function between send(TX) and receive(Rx) of RS485

rt.rs485_tx_rx_stat = "TX" # enable the send(TX) of RS485
rt.rs485_tx_rx_stat = "RX" # enable the receive(RX) of RS485