What is code B?

throbscottle · Nov 18, 2012

I've been looking at the MAX7219 bcd to 7 seg decoder again (thanks, picbits) after working through some other ideas - all more trouble than they're worth. Anyway, on the data sheet it shows the extra characters for bcd "code b" - can't find a description of what the extra E, H, L, P mean (well, ok it could spell HELP). Do these have specific designations apart from this?

TIA

dr pepper · Nov 18, 2012

I think they display extra characters other than 0 to 9, by the sound of it h,e,l,p.
Some of the cmos decoders will display a to f.

throbscottle · Nov 18, 2012

Oh it gives you a choice - A to F, or "code b" which is "-",e,h,l,p, and blank, which is far more useful to me. I just wondered if there were standard usages for the e h l p characters (apart from "help"). It's a great device - wish I'd taken it more seriously when picbits suggested it ages ago.

Mr RB · Nov 18, 2012

Surely v A C F would have been more useful?

7 seg displays are common in instruments like panel volt and ampmeters, temperature meters. Much more useful than the panel meter needing to say "HELP".

throbscottle · Nov 18, 2012

Well, I'll need to use "-" and blank for sure. The decoder can change code on the fly, so there's room to use both sets. I'm looking at it drive the display for a bench dmm project, so you're spot on there.

Mike odom · Nov 18, 2012

Mr RB said:
Surely v A C F would have been more useful?

7 seg displays are common in instruments like panel volt and ampmeters, temperature meters. Much more useful than the panel meter needing to say "HELP".

you can get the A C F with the binary display functions, but you'd need a 16 segment display to get a V...

throbscottle · Nov 19, 2012

I've read the data sheet properly now. Input registers can correspond to segments, or decode bcd to the mysterious "code b" - so it can be made to display pretty much anything. So for me the 8th digit will be status led's. Very very useful.

Mr RB · Nov 19, 2012

Mike odom said:
you can get the A C F with the binary display functions, but you'd need a 16 segment display to get a V...

I use the bottom 3 segments to make a lower case 'v'. That's a common technique.

What is code B?

throbscottle

Well-Known Member

dr pepper

Well-Known Member

throbscottle

Well-Known Member

Mr RB

Well-Known Member

throbscottle

Well-Known Member

Mike odom

Active Member

throbscottle

Well-Known Member

Mr RB

Well-Known Member

Similar threads

What is code B?

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Active Member

Well-Known Member

Well-Known Member

Similar threads

Privacy & Transparency

Privacy & Transparency