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你好，听起来很蠢，但是如果我使用内部振荡器只对水晶，我能期待什么？什么情况下是明智的，与其他世界在哪里必须是使用晶体振荡器模式只？或者如果使用内部VS外部晶体振荡器，会产生什么“副作用”。（我的意思是，这里主要是4MHz或最大8MHz，但不高）。我知道这是一个全球性的问题，但我只是对答案感到好奇，这就是我没有提到任何特定模块的原因。
以上来自于百度翻译 以下为原文 Hi there, Sounds stupid, but what can I expect if I'm using internal oscillator only vs crystal? What situation(s) is/are sensible, with other worlds where is the must be to use crystal oscillator mode only? Or what "side effect" can arising if I use internal vs external crystal oscillator. (I mean here mainly 4MHz or max 8MHz only, but not higher). I know it's a global question, but I'm just curious about answers, this is the reason why I'm not mentioning any particular module. 
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哪一张照片？近年来情况有了很大改善。这取决于：如果没有涉及到通信（更好：没有异步协议），基本上，您使用它们中的任何一个都足够安全：例如，没有协议，或者I2C，或者类似的。如果你正在做RS232或USB，你可能需要一个水晶或不可以。如果你处理极端温度，内部振荡器可能不够好。
以上来自于百度翻译 以下为原文 Which PIC? Things have improved a lot in the recent years Accuracy... it depends: if no communication (better: no asynchronous protocol) is involved, basically you are safe enough with any of them: say, no protocol, or I2C, or alike. If you need a precise Watch, you usually prefer a crystal. If you're doing RS232 or USB, you may need a crystal or may not. If you're dealing with extreme temperatures, internal oscillator may not be good enough. |
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内部振荡器的精确度一般在5%到0.2%之间，一些当前的PIC是1%，一些专门的PIC稍微好一些。它不太适合制作实时时钟。典型的（便宜的）晶体大约是20PPM，相当于0.002%。
以上来自于百度翻译 以下为原文 Internal oscillator accuracy is typically something like 5% to 0.2%. A number of current PICs are 1%, with a few specialised ones a bit better than that. 1% is only just good enough for doing serial communications. It's not very good for making a real time clock. A typical (cheap) crystal would be something like 20PPM, which is equivalent to 0.002% |
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根据数据表，PIC18F26K22有一个1%精确的内部振荡器，所以只要你能够将波特率设置得足够接近理想值，串行通信就可以了。对于I2C通信，定时一点也不重要，因为主（即你）控制所有的定时。通过时钟信号（SCL）。
以上来自于百度翻译 以下为原文 According to the datasheet, the PIC18F26K22 has a 1% accurate internal oscillator, so it will be ok for serial communications, so long as you are able to set the baud rate close enough to ideal. Timing is not critical at all for I2C communications, because the Master (i.e. you) control all the timing through the clock signal (SCL). |
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幸运的是，I2C不是一个高速版本，只有100k。我的系统由18f26k22组成，其中一位是主控者，他通过RS485与计算机进行通信。
以上来自于百度翻译 以下为原文 Fortunately I2C is not a high speed version, only 100k. My system is built about a bunch of 18f26k22 where one is a master, who is communicating via RS485 with computer. |
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如果串行COMM正在使用，会发生什么奇怪的事情（在速度上高达38 K400）？控制器是18F26k22，内部4MHz时钟。速度不是问题，而是精度。串行通信可以处理发送方和接收方之间高达3%的波特率失配。假设每端具有1%或更好的精度，它应该可以正常工作。不工作“意味着有时会损坏”。字符。正如我已经提到的。精度对I2C没有关系。所有的定时都与I2C SCL时钟信号有关，它连接在主机和从机之间。
以上来自于百度翻译 以下为原文 If serial comm is in use, can something strange happen (in speedwise up to 38k400)? The controller is a 18F26k22 clocked on internal 4MHz. The speed isn't the issue, it's the accuracy. Serial comms can cope with up to 3% mismatch in baud rates between sender and receiver. Assuming each end has 1% or better accuracy, it should work fine. "Not working" means sometimes getting corrupted characters. As I already mentioned. The accuracy does not matter for I2C. All timing is relative to the I2C SCL clock signal, which is connected between the Master and the Slave. |
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我也提到PIC18“K”系列已经足够好了。我只是没有检查整个温度范围，但我猜你不会太在意…
以上来自于百度翻译 以下为原文 And I mentioned that too PIC18 "K" series are good enough. I just did not check over the full temperature range, but I guess you won't care much... |
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温度在从属侧起作用，幸好没有伤害。如果我想得更深一点，对于在工业环境中工作的产品来说，硕士可能会产生影响。原来的设计不是我的，我只需要解决问题。这是原因之一，为什么我有这个问题。第二个原因是，找出设计中的弱点，避免在重新设计过程中出现问题。（可能我必须这样做：）
以上来自于百度翻译 以下为原文 Temperature play on Slave side, so luckily no harm. If I think a bit further, there is a possible effect on Master as this products working in industrial environment. The original design isn't mine, I just have to fix problems. This is one of the reasons, why I have this questions. The second reason is, find the weaknesses in this design and avoid at during redesign process. (Possible I have to do :) ) |
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要考虑的是，如果主和从两者都使用其内部振荡器添加错误。但是你使用的是PC，它有自己的水晶，所以你很好。注CAN总线通常需要外部振荡器的精度。
以上来自于百度翻译 以下为原文 One thing to consider is if the master and slave both are using their internal oscillators the errors add. But you are using a PC and that has its own Crystal , so you are good. Note CAN bus usually requires The accuracy of an external oscillator. |
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你非常小心…如果你使用UART，你还必须有一个在全温度范围内达到最大值+/-2%的从机…如果PIC18F26K22在-40到+85C和Vdd v2.7V到5.5V之间工作，它就不符合这个规格。作为主母通常是时钟从属。
以上来自于百度翻译 以下为原文 Hi Be very careful...if you use UART you must still have a slave which is garanteed for maximum +/-2% over the full temperature range...PIC18F26K22 does not meet this spec if it operates between -40 to +85C and Vdd v2.7V to 5.5V. On the other hand if you use I2C or SPI you d'ont care about the oscillator as the master is generally clocking the slave. Regards |
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谢谢大家，这就是我要找的答案。
以上来自于百度翻译 以下为原文 Thanks for everyone, this kind of answers what I'm looking for. |
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