MAX7219 Blank instruction?

[premelec]

I'm using Westy's sample code for learning about the MAX7219 - I wonder if there is a single instruction than blanks all digits [I've got an 8 digit display].
I'm using this for now:

FOR Idx =1 to 8
Register = Idx ; digit position
Data_7219 = DigBlank ; 15 will blank the digit in code B mode
GOSUB ShiftTo7219
NEXT Idx

Thanks...

PS No I don't want 'Shutdown'... I want to be ready for new single digit inputs...

 

[Pongo]

According to the datasheet "The display driver can be programmed while in shutdown mode" and "Typically, it takes less than 250µs for the MAX7219 to leave shutdown mode." so I don't think that would be a limitation.

 

[premelec]

pongo - Thanks for your suggestion but that's not what I'm trying to do - I'm trying to set all digits off - erased in effect. I guess they must be erased one by one only... shutdown keeps them all off - or keeps the data in registers & off.

 

[Pongo]

OK, sorry, I misunderstood. So you want to have a period between displaying values when nothing is displayed - is that right?

 

[premelec]

Clarify...

Well, sort of - I don't want anything showing - but _will_ show when written to... so blank all with '15' then write whatever later... The code above works ok I just wondered if there wasn't a single command like the shutdown that would write the '15' to all digits... no big deal - I'm just getting to know the chip. So many ways to do things.... - I haven't looked into the current draw with all digits blanked compared to shutdown etc... that will also be of interest... thanks for your input...

 

[Pongo]

No, as far as I know if you want to "display" 8 blanks you'll have to write 8 blanks. If you are concerned about seeing the display writing the digits one by one then in my experience using a 20x2 that's not an issue, but you could use shutdown to blank them all and then write the blanks and next data before turning it back on.

 

[John West]

Have you tried opening up the current set resistor line? If that works you might use a FET SW and a spare PICAXE control line to speed up turn on and turn off of everything at once.

You might also try a write to the brightness register to see if the minimum value appears to be "off" under normal light levels.