Testing communication with SARA R410M on iLab Challenger Board

test_coms_with_SARA_R4.py

import board
import busio
import digitalio
import time


uart = busio.UART(board.SARA_TX,board.SARA_RX,rts=board.SARA_RTS, cts=board.SARA_CTS, baudrate=115200,timeout=5)



# For most CircuitPython boards:
led = digitalio.DigitalInOut(board.LED)
led.direction = digitalio.Direction.OUTPUT


# Do a HW reset by applying a low pulse to the reset line for 1mSec
# bool Challenger2040LTEClass::doPowerOn() {
#   bool ret;
#   digitalWrite(PIN_SARA_PWR, HIGH);         // Make sure LDO is on
#   delay(100);                               // let the power stabilize
#   pinMode(PIN_SARA_ON, OUTPUT);             // Pull power on control low
#   delay(150);                               // For 150mS
#   pinMode(PIN_SARA_ON, INPUT_PULLUP);       // before releasing it again.
#   delay(1000);                              // Now wait for 1 second
#   SARA_SERIAL_PORT.begin(DEFAULT_SARA_BAUDRATE);
#   serialPortConfigured = true;
#   ret = isAlive();                          // Makie sure the modem is
#                                             // up and running
# 
#   delay(250);                               // Allow for any extra characters
#   // before flushing the input buffer
#   while(SARA_SERIAL_PORT.available()) SARA_SERIAL_PORT.read();
# 
#   return ret;
# }
# 
# 
# 
# SARA_BTN == PIN_SARA_ON

RESET_PIN = digitalio.DigitalInOut(board.SARA_RST)
RESET_PIN.direction = digitalio.Direction.OUTPUT

sara_pwr_on = digitalio.DigitalInOut(board.SARA_BTN)


def doPowerOn():
    time.sleep(0.1)
    sara_pwr_on.direction = digitalio.Direction.OUTPUT
    time.sleep(0.15)
    sara_pwr_on.switch_to_input(pull=digitalio.Pull.UP)
    time.sleep(1)
    
    
def resetModem(resetPin):

    led.value = True # set RGB to blue

    # toggle RST pin
    resetPin.value = 1
    time.sleep(0.1)
    print(sara_pwr_on.value)
    resetPin.value = 0
    time.sleep(0.15)
    print(sara_pwr_on.value)
    resetPin.value = 1
#     time.sleep(1)

    for x in range(0,5): # wait 5 seconds for modem to startup
        led.value = False # blink RGB
        time.sleep(0.5)
        led.value = True
        time.sleep(0.5)
    led.value = False
    print(sara_pwr_on.value)

# print(f"-= Reset Sara modem =-")
# print(f"-= and wait 5 sec. =-")
# resetModem(RESET_PIN)
print("Doing PowerOn")
doPowerOn()

print("Sending AT")
uart.write(bytes(f"AT\n","ascii"))
time.sleep(0.2)

while True:

    byte_read = uart.read(1)  # Read one byte over UART lines
    if byte_read is None:
        # Nothing read.
        continue

    if byte_read is not None:
        # Start of message. Start accumulating bytes, but don't record the ";".
        message = []
        print(byte_read)
        unit_present = True
        message_started = True
        continue
    
    if message_started:
        print("In message started")
        if byte_read in [b'\r', b'\n'] :
            print("Got carrige return")
            # End of message. Don't record the "\r or \n".
            # Now we have a complete message. Convert it to a string, and split it up.
            print(message)
            message_parts = "".join(message) #.split(",")
            print(message_parts)
            message_started = False
    
    
    else:
        # Accumulate message byte.
        print(f"Accumulating {byte_read}")
        message.append(chr(byte_read[0]))