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Modbus硬件控制03——485串口助手控制继电器 - 创客硬件开发 - 清泛IT社区...
...帖最后由 mzb2012 于 2025-08-28 21:58 编辑
1.软件准备485串口调试助手，它集成485调试功能，自带CRC校验，非常易于使用。
2.硬件连接
通过USB转485接入PC
3.测试步骤
发送字符串，一共两条指令
第一条是闭合继电器
第二条...
本地SQLite实现注册登录功能 - App Inventor 2 中文网 - 清泛IT社区，为创新赋能！
建表的SQL语句如下：
CREATE TABLE user(username TEXT PRIMARY KEY, password TEXT);
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最后提一下日志调试功能：
上面其实是用户密码信息，在日志控制台中能够输出便于调试查看。
PHP passing $_GET in linux command prompt
Say we usually access via
13 Answers
13
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Debug Error \"pure virtual function call\" 原因解析 - 更多技术 - 清泛...
...抛出异常的点已经很远了。所以这种情况相对来讲比较难调试。
三、析构函数与异常
好吧，我知道你忍了好久了，你早想喊出来："你本来就不该在析构函数中抛出异常！"，就像Scott同学说的：Item 11: Prevent exceptions from leaving d...
PHP “php://input” vs $_POST
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The reason is that php://input returns all the raw data after the HTTP-headers of the request, regardless of the content type.
The PHP superglobal $_POST, only is supposed to wrap data that is either
application/x-www-form-urlencoded (standard content type for...
What is a Python equivalent of PHP's var_dump()? [duplicate]
...lay a value nicely, you can use the pprint module. The easiest way to dump all variables with it is to do
from pprint import pprint
pprint(globals())
pprint(locals())
If you are running in CGI, a useful debugging feature is the cgitb module, which displays the value of local variables as part of...
“Notice: Undefined variable”, “Notice: Undefined index”, and “Notice: Undefined offset” using PHP
... can be used to detect if a variable has been already initialized. Additionally and more ideal is the solution of empty() since it does not generate a warning or error message if the variable is not initialized.
From PHP documentation:
No warning is generated if the variable does not exist. T...
How do I read any request header in PHP
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IF: you only need a single header, instead of all headers, the quickest method is:
<?php
// Replace XXXXXX_XXXX with the name of the header you need in UPPERCASE (and with '-' replaced by '_')
$headerStringValue = $_SERVER['HTTP_XXXXXX_XXXX'];
ELSE IF: you run PHP...
How to become an OpenCart guru? [closed]
It seems like they have no documentation except some api calls on their official forums. I have experience with Zend framework and CodeIgniter framework. Can any OpenCart masters recommend me the best way to learn it and master in shortest amount of time? I have to do a big project with it soon.
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How can I add a PHP page to WordPress?
...og that will execute my PHP code in it, whilst remaining a part of the overall site CSS/theme/design.
17 Answers
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