I was pulling up an old project (A little Simon game which has apparently fallen off the ‘net when I moved my site- will have to repost) to use as a classroom demonstration, and discovered that sometime in the last couple years, the int->unsigned long promotion in Ardino\/Processing broke\/changed without comment. <\/p>\n
The code uses using primitive nested counters and delays to generate sounds and control difficulty, which means rather large numbers (100-microsecond scale delays running for seconds) are being thrown about. To isolate the change, I wrote the following test: void setup() void loop() void testpromote(int input) void testpromote2(int input) Which generates this output: I was pulling up an old project (A little Simon game which has apparently fallen off the ‘net when I moved my site- will have to repost) to use as a classroom demonstration, and discovered that sometime in the last … Continue reading
\n
\nint constint = 500;<\/p>\n
\n{
\n Serial.begin(9600);
\n}<\/p>\n
\n{
\n testpromote(constint);
\n testpromote2(constint);
\n delay(1000);
\n}<\/p>\n
\n{
\n Serial.print(\"Multiplying:\");
\n Serial.print(input);
\n Serial.println(\"*1000\");
\n unsigned long result;
\n result=input*1000;
\n Serial.print(\"Result:\");
\n Serial.println(result);
\n}<\/p>\n
\n{
\n Serial.print(\"Multiplying:\");
\n Serial.print(input);
\n Serial.println(\"*1000L\");
\n unsigned long result;
\n result=input*1000L;
\n Serial.print(\"Result:\");
\n Serial.println(result);
\n}<\/code><\/p>\n
\n
\nMultiplying:500*1000
\nResult:4294943008
\nMultiplying:500*1000L
\nResult:500000
\n<\/code>
\nNote that ul=int*int produces something *distinctly wrong*, while ul=long*int produces a valid result. Easy to work around, but somewhat alarming. <\/p>\n","protected":false},"excerpt":{"rendered":"