4 years, 10 months ago.

seriallcd not working? showing error on write command. Please help

I am using tx rx serial lcd. https://www.sparkfun.com/tutorials/246.


#include "mbed.h"
//#include "SerialLCD.h"
#include "TextLCD.h"

DigitalOut myled(LED1);
//SoftSerial SoftSerial(PinName p9, PinName NC, const char* name = NULL);
Serial mySerial(NC, p9);
int temp, rpm;
char tempstring[10], rpmstring[10]; // create string arrays

void setup()
  mySerial.baud(9600); // set up serial port for 9600 baud
  wait(500); // wait for display to boot up

  mySerial.write(254); // cursor to beginning of first line

  mySerial.write("RPM:            "); // clear display + legends
  mySerial.write("TEMP:           ");

void loop() 
  temp = rand(1000); // make some fake data
  rpm = rand(10000);

  mySerial.printf(tempstring,"%4d",rpm); // create strings from the numbers
  mySerial.printf(rpmstring,"%4d",temp); // right-justify to 4 spaces

  mySerial.write(254); // cursor to 7th position on first line
  mySerial.write(rpmstring); // write out the RPM value

  mySerial.write(254); // cursor to 7th position on second line

  mySerial.write(tempstring); // write out the TEMP value
  wait(1000); // short delay

int main() {
    while(1) {
        myled = 1;

Jay, which pin on your board is being used for the TX pin for the serial output ? Serial mySerial(NC, p9); cannot use NC for the TX definition

see here for more details: https://developer.mbed.org/handbook/Serial. Suggest to comment out all access to the serial port and work on a single serial output line. Move forward after the single line is working correctly.

posted by Sanjiv Bhatia 08 Nov 2016

Error: Function "mbed::Stream::write" (declared at <a href="#" onmousedown="mbed_doc_goto('/mbed_lcdtesterextras/mbed_25aea2a3f4e3/Stream.h', '52'); return false;">/extras/mbed_25aea2a3f4e3/Stream.h:52</a>) is inaccessible in "main.cpp", Line: 16, Col: 13

this error is shown when compiled. Can you explain me please.

posted by jayendra mishra 08 Nov 2016
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Assigned to Graham Moore 4 years, 10 months ago.

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