[英]Declaration function pointer C++ arduino 1.6.11
我是C ++的初學者,但對於我的arduino,我需要此代碼。 它正在為較低版本的arduino進行編譯和工作,例如arduino-1.6.5.r5。 從1.6.9起,甚至是最新版本的arduino(1.6.11),此聲明都不再編譯。 我不完全理解該錯誤。 可以用其他方式重寫嗎? 我正在使用圖書館CallBack.h。
庫的來源: https : //bitbucket.org/ehsmaes/cmdcallback/wiki/Home
庫中的示例
#include <CallBack.h>
// Compile and upload to arduino. Run the serial monitor and type command
// :help;
// Values for initiation of cmd/response interface.
// After initial boot, id, gid and del are stored in eeprom.
// Change values by command. Make sure each device has a unique id.
String descr="Command/response test program v0.1";
String id="a1";
String gid="a";
int del=0; //delayed response
// List of commands defined by keyword, funtion pointer, number of arguments
// and description used in "help" command.
CallBackDef f[] = {
{(String)"add", (FunctionPointer)&add, (int)2, (String)":num1:num2"}
};
// initiate command handler: function array, number of functions and intial values
CallBack cmd(f, sizeof(f) / sizeof(*f), id, gid, descr, del);
void setup() {
Serial.begin(9600);
cmd.ok(); // say hello
}
void loop() {
// Put code here. Use timers instead of delay if possible as not to disrupt
// command/response interaction with host
}
void serialEvent() {
// Don't forget this line. Parse command if serial data is available.
cmd.cmdCheck();
}
// --------- command initiated callback functions below ---------
// callback functions all need to be defined void and with String argv
// argument list. The command parser will validate the number of input
// parameters but any additional validation has to be perfomed by each
// callback function. As the argument list is passed as strings, type
// casting to other types is the responsibility of the function.
void add(String argv[]) {
int a = cmd.stoi(argv[0]);
int b = cmd.stoi(argv[1]);
cmd.respond(String(a + b));
}
`
CmdCallBack_example_minimum:17: error: 'add' was not declared in this scope
{(String)"add", (FunctionPointer)&add, (int)2, (String)":num1:num2"}
^
Using library CmdCallBack in folder: /Users/adrian/ownCloud/Arduino/libraries/CmdCallBack (legacy)
exit status 1
'add' was not declared in this scope
此錯誤意味着在CallBackDef f[] = ...
之前未聲明函數baseevent
。 您需要在使用函數原型之前或函數定義(在使用函數之前=完整函數)。
Arduino中還有另一個預處理器,負責處理這些定義,並將它們放置在草圖開始處。 但是通常會破壞任何更復雜的東西(生成的原型是完全錯誤的),因此即使合法的c ++代碼也無法編譯。 有時它會改變Arduino版本之間的行為。
示例CmdCallBack_example_minimum在1.6.9中默認情況下不起作用,但是,如果您添加函數原型,則:
#include <CallBack.h>
// Compile and upload to arduino. Run the serial monitor and type command
// :help;
// Values for initiation of cmd/response interface.
// After initial boot, id, gid and del are stored in eeprom.
// Change values by command. Make sure each device has a unique id.
String descr="Command/response test program v0.1";
String id="a1";
String gid="a";
int del=0; //delayed response
byte echo=1; // command back to host
// ------------------------------------------------
// Function Prototype for add:
void add(String argv[]);
// List of commands defined by keyword, funtion pointer, number of arguments
// and description used in "help" command.
CallBackDef f[] = {
{(String)"add", (FunctionPointer)&add, (int)2, (String)":num1:num2"}
};
// initiate command handler: function array, number of functions and intial values
CallBack cmd(f, sizeof(f) / sizeof(*f), id, gid, descr, del, echo);
void setup() {
Serial.begin(9600);
cmd.ok(); // say hello
}
void loop() {
// Don't forget this line. Parse command if serial data is available.
cmd.cmdCheck();
// Put code here. Use timers instead of delay if possible as not to disrupt
// command/response interaction with host
}
// --------- command initiated callback functions below ---------
// callback functions all need to be defined void and with String argv
// argument list. The command parser will validate the number of input
// parameters but any additional validation has to be perfomed by each
// callback function. As the argument list is passed as strings, type
// casting to other types is the responsibility of the function.
void add(String argv[]) {
int a = cmd.stoi(argv[0]);
int b = cmd.stoi(argv[1]);
cmd.respond(String(a + b));
}
沒有顯式函數原型的Arduino預處理器會處理它,但是它會在使用它的行之后插入。 因此仍然存在錯誤。
但是,即使在修復后,您的版本也會被破壞(CallBack cmd中的某些錯誤參數類型...)
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