用于PIC18F45K50的I2C每个字节都被交换

嗨，我也有IC2的问题。看看我的线。也许有一个为你服务……“PIC18F46K22I2C不工作”



      以下为原文

    Hi,

I have problems with IC2, too. Look at my thread. Maybe there is a solutotion for you...

"PIC18F46K22 I2C doesn´t work"
 

嗨，代码1中的代码似乎是一个合理的第一次努力，也许大部分是从某处借来的。在I2C.MistRoad Wrand（…）中交换；永远不能工作，因为这会损坏I2C从地址，这是在数据字节之前发送的。我将检查PCF88A扩展之间的连接。R和任何与一些可疑的事物有关。请注意，当在一个字节内标记位时，最低值表示最低有效位。我期望0xf0出现为p7＝1，p6＝1，p5＝1，p4＝1，p3＝0，p2＝0，p1＝0，p0＝0。但此扩展器旨在驱动与电阻器连接到VCC的LED指示器，P。在这方面，低输出会使LED亮起来，高输出会使它变暗。而不是改变位序列，你可以尝试颠倒数据字节。倾斜'~’字符是C语言运算符的“位不”，这意味着每个位都颠倒过来。读取PCF87A扩展器数据表，可以从TI网站下载。迈西尔



      以下为原文

    Hi,
Code in message #1 seem like a reasonable first effort, maybe most of it is borrowed from somewhere.
Swapping in   I2C_Master_Write(...); could never work,
because that would mangle the I2C slave address, that is sent before the data bytes.
 
I would examine the connection between the PCF8574A expander and whatever with some doubth.
What is connected to bits ?
Be aware that when labeling bits within a byte, then the lowest number mean the least significant bit.
I would expect 0xF0 to appear as P7 =1, P6 = 1, P5 = 1, P4 = 1, P3 = 0, P2 = 0, P1 = 0, P0 = 0.
 
But this expander is intended to drive LED indicators that are connected with a resistor to Vcc, the positive power supply.
In this connection, a Low output will make the LED light up, and High output will make it dark.
Instead of changing sequence of bits, you may try to Invert the data byte only.
   I2C_Master_Write( ~ 0xF0 );    
the tilde '~' character is a C language operator 'bitwise not' that mean each bit be turned upside down.
 
Read Datasheet for PCF8574A expander, it can be downloaded from TI website.
 
   Mysil

感谢所有，我解决了我的问题，这似乎是我使用错误的从地址。现在我已经为I2C实现了功能，但是现在我遇到了一个新的问题。我可以通过设置光标回家和闪烁来设置LCD。但是，由于某种原因，当我发送数据而不是命令时，我不能使它工作。我在想，也许是连接到液晶显示器的RS引脚的PIN不能正常工作，但是当我尝试将数据发送到LCD时，它实际上打开了。事实上，所有的I2C模块的引脚工作。我把我项目的链接发送给你。http://Github.com／Helo…20编程/计时器。谢谢！



      以下为原文

    Thanks to all,
 
I solved my problem and it all seemed to be that I was using the wrong slave address. Now the functions I have implemented for I2C work, but now I encounter a new problem. I am able to setup the LCD by setting the cursor home and blinking. But, for some reason, I cannot make it work when I send data instead of commands. I was thinking that perhaps the pin that is connected to the Rs pin of the LCD was not working properly, but it actually turns on when I try to send data to the LCD. In fact, all pins of the I2C module work. I send you the link of my project.
 
https://github.com/hearco...20programming/TIMERS.X
 
Thanks!

这是正确的计划吗？在那里我看不到任何I2C或LCD代码，只是定时器。



      以下为原文

    Is that the right project?
I cannot see any I2C or LCD code in there, just timers.
 

可能是这个。



      以下为原文

    Probably this instead.

HI，在GITHUB上发布的代码，下面的字节将从I2C主机转移：无论PCF扩展器和LCD显示器之间的布线如何安排，使用I2CYLCDWRead字节（…）发送4位命令到显示控制器，将扰乱所有以下命令的同步在接收到4位命令的第一个字节后，显示控制器将改变通信模式，最好单独做一个功能，发送一个半字节到显示控制器。我没有看到任何配置位设置，所以不知道什么频率的CH。IP实际上是运行的。对于I2C通信来说，实际频率并不重要，只要它不是太高，但是显示控制器对一些命令有不同的时序要求。如果通信的定时被提高，一些命令可能需要额外的延迟。周围的小乌鸦。问候，Mysil



      以下为原文

    Hi,
With the code posted on Github,
the following bytes will be transferred from I2C master:
Start
0x7E               //  I2C slave address

0x4C    E^         //  4bit
0x48    Ev
0x1C    E^
0x18    Ev 
             >     /* After 4bit command have been given, display controller will take these two nibbles together */
0x0C    E^  /      // Clear screen
0x08    Ev /
0x8C    E^
0x88    Ev 
             >
0x0C    E^  /      // Cursor ON
0x08    Ev /
0xFC    E^
0xF8    Ev
 
        ...  
Whatever way the wiring between PCF expander and LCD display may be arranged,
using I2C_LCD_WriteByte(...) to send the 4-bit command to Display controller,
will mess up synchronization for all following commands and data.
Immediately after receiving the first nibble of 4-bit command, display controller will change communication mode.
It will be better to make a separate function to send a single Nibble to display controller.
 
I have not seen any Configuration bit settings, so do not know what frequency the chip is actually running.
For I2C communication, actual frequency do not matter, as long as it is not much too high,
but Display controller have different timing requirements for some commands.
If timing in communication is thightened up, additional delay may be needed for some commands.
 
There are some other small uglies around.
 
Regards,
   Mysil

对不起，DavidBlit是对的。这是一个项目：http://Github.com／HyoCo／PIC18/Trime/Mc/C%20%编程/I2CLCD。XMysil，UC工作在16MHz，但我将在项目上添加明确的配置来解决这个问题。我知道LCD有它自己的时间要求，但是我在想如果我能把LCD打开和闪烁，我也能显示任何字符，但是它没有发生。我想我会再次检查时间要求，看看数据是否被正确地发送。此外，我还要检查发送的NIbBLE函数，看看它是否有效，并在这里发布我的更新。



      以下为原文

   
Sorry, DavidBlit is right. This is the project: https://github.com/hearco/PIC18/tree/master/C%20programming/I2C_LCD.X
 
Mysil,
 
The uC is working at 16MHz, but I will add explicit configurations on the project to address that. I know that the LCD has its own time requirements, but I was thinking that if I am able to set the LCD on and blinking, I should be able to display any character as well, but it is not happening. I think I will check on the time requirements again to see if a data is not being sent properly.
 
Also, I will also check on the sending nibbles function to see if that works and post my update here.
 
Thanks all,