QUESTION: BCD or BINARY?

After re-reading Hippy's famous BCD to decimal code snippet, this question occurred to me.

Where you had to

• read the values of two 16-bit counters to get LSB and MSB separately
• combine the resulting 16-bit word (LSB) with another 16-bit word (MSB) somehow to get a total count
• subtract that total from a starting count to get an "elapsed" count
• present the "elapsed" count to a visible display

Would you choose to accumulate the count in BINARY or BCD?

Binary for simplicity. To me, BCD is only for simplified presentation of numbers.

Agreed and binary makes more efficient use of memory and serial bandwidth.

I would go with binary. Trying to do maths with BCD numbers can easily become a nightmare so often ends up converting to binary to do that anyway.

Another vote to use binary - the "native" language of most microcontrollers and computers (analog computers and a few others do exist)

Texasclodhopper said:

• ... read the values of two 16-bit counters to get LSB and MSB separately ...

Click to expand...

Is the combined raw count a 32bit number divided into two 16bit words ?

The PICAXE can't read a 32bit number in one operation, so you will have issues when the two 16bit values are read at two seperate times.

You need some method of latching the 32bit value while the read operations take place.

Are these counters in the PICAXE, or external ?

Cheers,

Buzby

Counter is actually external, the outputs are latched, and I will have to deal with two 16-bit words (8-bit nibbles) within the PICAXE to get the total elapsed time. (I'm not expecting any more than 24-bit significance and may mask off the most significant 8-bits.)

I wasn't going there yet, because I don't really have any coding done, but I will have to deal with some math involving the 32-bit number; such as "which 32-bit number is greater" comparison.

The ultimate goal is to transmit the 32-bit number as ASCII via a serial link.

PS. Sounds like since I'm not going to directly transfer the count to a display, BINARY is the hands-down winner.

Texasclodhopper said:

The ultimate goal is to transmit the 32-bit number as ASCII via a serial link.

Click to expand...

There is code on the forum for converting 32-bit binary into decimal / ASCII digits, including ...

http://www.picaxeforum.co.uk/showthread.php?14669-32-bit-DWORD-expressed-in-ASCII-uALFAT-DWORD-to-ascii&p=127083&viewfull=1#post127083

Thanks to all of y'all for your input. Much appreciated.

Just to be complete on some 32-bit math mentioned previous, here's a link to Alleycat's routines.

32-bit Addition and Subtraction

Thanks, again.