Progmem Compiler Errors 1.8.3

Projects Programming
1

Greetings
I've been using the PROGMEM method for years without problem based exactly on the sample code (PROGMEM string demo) from the playground. I have just upgraded to IDE 1.8.3 and the sketch no longer compiles.

I then tried to compile the sample code from the playground and that also fails to compile with exactly the same errors. The output from the compiler is copied below.

A Google search on PROGMEM Compile errors didn't yield anything so clearly I am missing something. Any guidance would be much appreciated.

Arduino: 1.8.3 (Windows 7), Board: "Arduino/Genuino Uno"

Progmem_test:20: error: 'prog_char' does not name a type

 prog_char string_0[] PROGMEM = "String 0";   // "String 0" etc are strings to store - change to suit.

 ^

Progmem_test:21: error: 'prog_char' does not name a type

 prog_char string_1[] PROGMEM = "String 1";

 ^

Progmem_test:22: error: 'prog_char' does not name a type

 prog_char string_2[] PROGMEM = "String 2";

 ^

Progmem_test:23: error: 'prog_char' does not name a type

 prog_char string_3[] PROGMEM = "String 3";

 ^

Progmem_test:24: error: 'prog_char' does not name a type

 prog_char string_4[] PROGMEM = "String 4";

 ^

Progmem_test:25: error: 'prog_char' does not name a type

 prog_char string_5[] PROGMEM = "String 5";

 ^

Progmem_test:30: error: variable 'string_table' must be const in order to be put into read-only section by means of '__attribute__((progmem))'

 PROGMEM const char *string_table[] =     // change "string_table" name to suit

                                  ^

Progmem_test:32: error: 'string_0' was not declared in this scope

   string_0,

   ^

Progmem_test:33: error: 'string_1' was not declared in this scope

   string_1,

   ^

Progmem_test:34: error: 'string_2' was not declared in this scope

   string_2,

   ^

Progmem_test:35: error: 'string_3' was not declared in this scope

   string_3,

   ^

Progmem_test:36: error: 'string_4' was not declared in this scope

   string_4,

   ^

Progmem_test:37: error: 'string_5' was not declared in this scope

   string_5 };

   ^

exit status 1
'prog_char' does not name a type

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.
2

Do you think that it would be helpful if you posted the program that is causing the errors ...

3

Please post a link to the playground page where you found this code. Use the chain links icon on the toolbar when you post links to make them clickable.

4

Thanks for swift responses. The example code giving errors from the playground is at:Arduino Playground - PROGMEM

My sketch uses this example code directly, only changing the field names.

The errors from the compiler are in my original post above

That code is:

/*
PROGMEM string demo
How to store a table of strings in program memory (flash),
and retrieve them.

Information summarized from:
http://www.nongnu.org/avr-libc/user-manual/pgmspace.html

Setting up a table (array) of strings in program memory is slightly complicated, but
here is a good template to follow.

Setting up the strings is a two-step process. First define the strings.

*/

#include <avr/pgmspace.h>
prog_char string_0[] PROGMEM = "String 0"; // "String 0" etc are strings to store - change to suit.
prog_char string_1[] PROGMEM = "String 1";
prog_char string_2[] PROGMEM = "String 2";
prog_char string_3[] PROGMEM = "String 3";
prog_char string_4[] PROGMEM = "String 4";
prog_char string_5[] PROGMEM = "String 5";

// Then set up a table to refer to your strings.

PROGMEM const char *string_table[] = // change "string_table" name to suit
{
string_0,
string_1,
string_2,
string_3,
string_4,
string_5 };

char buffer[30]; // make sure this is large enough for the largest string it must hold

void setup()
{
Serial.begin(9600);
}

void loop()
{
/* Using the string table in program memory requires the use of special functions to retrieve the data.
The strcpy_P function copies a string from program space to a string in RAM ("buffer").
Make sure your receiving string in RAM is large enough to hold whatever
you are retrieving from program space. */

for (int i = 0; i < 6; i++)
{
strcpy_P(buffer, (char*)pgm_read_word(&(string_table*))); // Necessary casts and dereferencing, just copy.*

  • Serial.println( buffer );*
  • delay( 500 );*
  • }*
    }
5

See the progmem reference

prog_char is outdated to my knowledge

6

Damn, that code is outdated... Fixed it :stuck_out_tongue:

All variables with the prog_ prefix no longer exist :slight_smile:

7

Many thanks for swift resolution. Very impressive. I note the playground has been updated to reflect that prog_char is outdated..

8

Bigworrier:
Thanks for swift responses. The example code giving errors from the playground is at:Arduino Playground - HomePage

My sketch uses this example code directly, only changing the field names.

The errors from the compiler are in my original post above

That code is:

You forgot to linkify the URL and to use code tags.

septillion:
Fixed it :stuck_out_tongue:

Thanks septillion!