PIC32MX150F128B 5V耐压引脚怎么连接

哪个收发器？什么是有效的高和低电压水平在其发射机输入引脚？为什么？你会让他们打开集电极输出吗？你想让他们做什么？这意味着引脚可以容忍5V的输入而不损坏。你现在指的是什么引脚？这个匿名收发器？



      以下为原文

   
Which transceiver? What are the valid high & low voltage levels on its transmitter input pin?
 

Why. Are you going to make them open collector outputs?
 

What do you want them to do?
 

It means the pin can tolerate 5V input without damage.
 

What pins are you referring to now?
On this unnamed transceiver?

你好！我要使用P48。它将根据数据表使用3.3V信号！我知道控制器的插销有内部的拉起，但以防万一我想添加外部。所以我认为RO引脚将连接到RX UC引脚上拉电阻参考+5V，使能和RI引脚将连接到上拉到3.3V。谢谢！



      以下为原文

    Hi! I`m going to use SP485EEN. It`s going to work with 3.3V signals according to the datasheet! 
I know the controller`s pins have internal pull-ups, but just in case I want to add external. So I think RO pin will be connected to RX uC pin with pull-up resistor refered to +5V, and the enable and RI pins will be connected to pull-up refering to 3.3V.
Thanks!

如果你要把接收器关掉，那么RO会漂浮，所以是的，一个上拉将保持它的有效性。它可以是3.3V或5V，这不重要。为什么你需要弹出？如果你不浮动PIC引脚驱动这些信号，就不需要上拉。



      以下为原文

   
If you're doing to turn the receiver off, then RO will float, so yes a pullup wll keep it valid.
It can be 3.3V or 5V, doesn't matter which.
 

Why do you need pullups at all?
If you don't float the PIC pins driving these signals, there's no need for pullups.
 

我假设你已经重新连接到一个PIN，这也是我们做事的方式。然而，我强烈建议在Re/DE线上下拉，或者你指的是：E.为什么？如果你的PIC去了KAPUT，猜猜总线发生了什么：你的485芯片将处于传输模式。就像一个胖子坐在操场上的跷跷板上一样，没有其他设备能够进入你的网络，因为芯片会占用线路。这将导致管理变得绝对猿***，并不是很容易在现场进行故障排除。



      以下为原文

    I'm assuming that you have RE and DE connected to a single pin; it's the way we do things as well. However I would strongly recommend a PULLDOWN on the RE/DE line, or as you refer to it: E. Why? If your PIC goes kaput, guess what happens to the bus: your 485 chip will be in transmit mode. Like a fat kid sitting on a seesaw on the playground, no other devices will be able to access your network as that chip will be hogging the line. This will lead to management going absolutely ape**** and it's not exactly easy to troubleshoot in the field.