6. How to handle Uplink & Downlink Messages?

This section will add in LCD functions to display on the LCD display. If the adding of LCD peripheral was not explored, please skip this section as well. Otherwise, please visit the documentation of adding a LCD peripheral first.

First, we will head down to our Private functions on line 312 and add in another LCD Display function as seen below to display our received downlink message.

void LCDPrintMsg(char Msg_Format[16], int Cursor_1, int Cursor_2, bool Clear) //Murata - Added function that prints msg on LCD Display { if (Clear == true) //Murata- If user puts fourth parameter as true, then clear the screen before printing { clear(); } display(); //Murata - Turn on LCD from sleep setCursor(Cursor_1, Cursor_2); //Murata – Sets cursor to print on LCD, e.g. setCursor(0, 0) will print in 1st column, 1st row sprintf(Rx_Message, Msg_Format, Rx_Characters); //Murata - Stores Rx_Characters in consecutive bytes at address of MSG string print(Rx_Message); //Murata - Prints message on LCD screen }

*Note: This LCD function is different from the previous as this is used to print the downlink messages whereas the previous LCD function is used to print the sensor data

Next, we will proceed to print our LCD messages for each individual functions in OnRxData. Go to line 360 and add in the line below.

*Note: This line prints the downlink message to the LCD Display

LCDPrintMsg("Rx Msg: 0x%x", 0, 0, true); //Murata - Calls LCD function to print downlink message on LCD Display

Next, go to line 366 onwards which is inside case 0 of LORAWAN_SWITCH_CLASS_PORT and add the following LCD print lines.

Next, go to line 400 onwards which is the case of LORAWAN_USER_APP_PORT and add the following LCD print lines.

Next, go to line 433 onwards which is the case of LORAWAN_CHANGE_TX_PERIOD_PORT and add the following LCD print lines.

Finally, rebuild all files, load it into 1SJ and press reset button. Send some downlink messages and observe the LCD display the received messages as well as the respective change in settings.

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