pySerialTransfer

Python package to transfer data in a fast, reliable, and packetized form.

If using this package to communicate with Arduinos, see https://github.com/PowerBroker2/SerialTransfer for the corresponding and compatible library (also available through the Arduino IDE's Libraries Manager).

To Install

pip install pySerialTransfer

Example Python Script

import time
from pySerialTransfer import pySerialTransfer as txfer


if __name__ == '__main__':
    try:
        link = txfer.SerialTransfer('COM17')
        
        link.open()
        time.sleep(2) # allow some time for the Arduino to completely reset
        
        while True:
            send_size = 0
            
            ###################################################################
            # Send a list
            ###################################################################
            list_ = [1, 3]
            list_size = link.tx_obj(list_)
            send_size += list_size
            
            ###################################################################
            # Send a string
            ###################################################################
            str_ = 'hello'
            str_size = link.tx_obj(str_, send_size) - send_size
            send_size += str_size
            
            ###################################################################
            # Send a float
            ###################################################################
            float_ = 5.234
            float_size = link.tx_obj(float_, send_size) - send_size
            send_size += float_size
            
            ###################################################################
            # Transmit all the data to send in a single packet
            ###################################################################
            link.send(send_size)
            
            ###################################################################
            # Wait for a response and report any errors while receiving packets
            ###################################################################
            while not link.available():
                # A negative value for status indicates an error
                if link.status.value < 0:
                    if link.status == txfer.Status.CRC_ERROR:
                        print('ERROR: CRC_ERROR')
                    elif link.status == txfer.Status.PAYLOAD_ERROR:
                        print('ERROR: PAYLOAD_ERROR')
                    elif link.status == txfer.Status.STOP_BYTE_ERROR:
                        print('ERROR: STOP_BYTE_ERROR')
                    else:
                        print('ERROR: {}'.format(link.status.name))
            
            ###################################################################
            # Parse response list
            ###################################################################
            rec_list_  = link.rx_obj(obj_type=type(list_),
                                     obj_byte_size=list_size,
                                     list_format='i')
            
            ###################################################################
            # Parse response string
            ###################################################################
            rec_str_   = link.rx_obj(obj_type=type(str_),
                                     obj_byte_size=str_size,
                                     start_pos=list_size)
            
            ###################################################################
            # Parse response float
            ###################################################################
            rec_float_ = link.rx_obj(obj_type=type(float_),
                                     obj_byte_size=float_size,
                                     start_pos=(list_size + str_size))
            
            ###################################################################
            # Display the received data
            ###################################################################
            print('SENT: {} {} {}'.format(list_, str_, float_))
            print('RCVD: {} {} {}'.format(rec_list_, rec_str_, rec_float_))
            print(' ')
    
    except KeyboardInterrupt:
        try:
            link.close()
        except:
            pass
    
    except:
        import traceback
        traceback.print_exc()
        
        try:
            link.close()
        except:
            pass

Example Arduino Sketch

#include "SerialTransfer.h"


SerialTransfer myTransfer;


void setup()
{
  Serial.begin(115200);
  myTransfer.begin(Serial);
}


void loop()
{
  if(myTransfer.available())
  {
    // send all received data back to Python
    for(uint16_t i=0; i < myTransfer.bytesRead; i++)
      myTransfer.packet.txBuff[i] = myTransfer.packet.rxBuff[i];
    
    myTransfer.sendData(myTransfer.bytesRead);
  }
}

Example Python Script with Callback Functionality

Note that you can specify many callbacks, but only one per packet ID

import time
from pySerialTransfer import pySerialTransfer as txfer


def hi():
    '''
    Callback function that will automatically be called by link.tick() whenever
    a packet with ID of 0 is successfully parsed.
    '''
    
    print("hi")
    
'''
list of callback functions to be called during tick. The index of the function
reference within this list must correspond to the packet ID. For instance, if
you want to call the function hi() when you parse a packet with an ID of 0, you
would write the callback list with "hi" being in the 0th place of the list:
'''
callback_list = [ hi ]


if __name__ == '__main__':
    try:
        link = txfer.SerialTransfer('COM17')
        
        link.set_callbacks(callback_list)
        link.open()
        time.sleep(2) # allow some time for the Arduino to completely reset
        
        while True:
            link.tick()
    
    except KeyboardInterrupt:
        link.close()
    
    except:
        import traceback
        traceback.print_exc()
        
        link.close()