I am trying to port a library and need help with a unit conversion.

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I am trying to port a library and need help with a unit conversion.

(6 posts) (3 voices)

Started 3 years ago by Cyclegadget
Latest reply from gbulmer

Cyclegadget
Member

I am trying to port the MCP2451 spi digital pot to the maple. I am using Notepad++ to edit my .h and .cpp files. I am gradually getting closer. I have got to this piece of code in the .h and I am not sure what the proper way is to convert these commands. I think it may need to be specified as Hex but, I am not sure. I just need to change the B00000000 parts.

Please help,
Mark

( const static uint8 kADR_WIPER0 = B00000000;
const static uint8 kADR_WIPER1 = B00010000;

const static uint8 kCMD_READ = B00001100;
const static uint8 kCMD_WRITE = B00000000;

const static uint8 kADR_VOLATILE = B00000000;
const static uint8 kADR_NON_VOLATILE = B00100000;

const static uint8 kTCON_REGISTER = B01000000;
const static uint8 kSTATUS_REGISTER = B01010000;)

Posted 3 years ago #
gbulmer
Moderator
Put a zero, 0, in front of the things that look a bit like numbers.
So B00001100 becomes 0B00001100.
I find it easier to read using a lower case 'b', and so would be 0b00001100.

If you have *all* of the code available, I think it will compile correctly anyway. I think it used to be there was a set of defined names, e.g.
```
#define B00000000 (0)
#define B00000001 (1)
#define B00000010 (1)
#define B00000100 (1)
```
but it might be an enum or const's now.
Posted 3 years ago #
Cyclegadget
Member

Thank you for the reply and the simple fix. If I am successful, I will share my files.

Posted 3 years ago #
bubulindo
Member

Still #define in wirish\bit_constants.h

Posted 3 years ago #
Cyclegadget
Member

Thanks bubulindo for the reply.

The code I have started with is here: https://github.com/teabot/McpDigitalPot

I got it to work with an Arduino Uno.

I want to take your guys advice about:
#define B00000000 (0)
#define B00000001 (1)
#define B00000010 (1)
#define B00000100 (1)

and:
Still #define in wirish\bit_constants.h

But I am not sure how or where yet. I have been using the "Compile and Error" method" to step through finding problems with the .h and .cpp files. I have started the quest with fixing data types and later, I will have to fix the spi to hardware spi issue.

I am trying to at least do my part first before asking for more help. Some of it has not been hard but, I have just started.

Posted 3 years ago #
gbulmer
Moderator

Cyclegadget - the ... #define B00000001 (1) ... was an old fix which is no longer needed.

In the past, the C/C++ compiler only supported three ways to write literal binary numbers: base 10, base 8 (0...), and base 16 (0x...).

Sometimes it is easier to understand what is happening when the number is written in base 2, so those names were created to help make those cases easier to understand.

Now, GNU's C/C++ compiler supports writing binary numbers using 0b00..., so those old names aren't needed any more.
IMHO, save yourself effort, and use the binary number.

Posted 3 years ago #

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