MAX7219 AppKit

Archiver

In case someone doesn't know.

Just got my MAX7219 LED Driver AppKit and have it up and running. It
receives the time from my DS1302 "master clock" via RF and displays hours and
minutes on a four-digit multiplex module from Mouser.

Had a problem trying to turn on the Dp after the second digit to sort of
separate hours from minutes, and I could find nothing in the AppKit
documentation to explain how to do it. Finally figured out that if I add 128
to digit 2 it turns on the Dp. For instance I originally wrote

dig2 = timestr(1) (Incoming time from the master is received as
str timestr\4. Dig2 refers to the second number,
not to the 2nd digit cathode control.)

I changed it to

dig2 = timestr(1) + 128

The second digit plus the Dp now turns on. It follows that you can turn on
the Dp after any digit just by adding 128 to the digit.

Sid - W4EKQ




[noparse][[/noparse]Non-text portions of this message have been removed]

Archiver

I'm going to be dabbling with the 7219 in the distant future....it'll
be connected to a 4 dig LED display in the jukebox I am building. It
will be forging new ground for me, might bug ya with a question or
two! [noparse]:)[/noparse]

--- In basicstamps@y..., Newzed@a... wrote:
> In case someone doesn't know.
>
> Just got my MAX7219 LED Driver AppKit and have it up and running.
It
> receives the time from my DS1302 "master clock" via RF and displays
hours and
> minutes on a four-digit multiplex module from Mouser.
>
> Had a problem trying to turn on the Dp after the second digit to
sort of
> separate hours from minutes, and I could find nothing in the AppKit
> documentation to explain how to do it. Finally figured out that if
I add 128
> to digit 2 it turns on the Dp. For instance I originally wrote
>
> dig2 = timestr(1) (Incoming time from the master is received as
> str timestr\4. Dig2 refers to the
second number,
> not to the 2nd digit cathode control.)
>
> I changed it to
>
> dig2 = timestr(1) + 128
>
> The second digit plus the Dp now turns on. It follows that you can
turn on
> the Dp after any digit just by adding 128 to the digit.
>
> Sid - W4EKQ
>
>
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]

Archiver

For bdalziel............

Good morning

Suggest you use the 4-digit multiplex module from Mouser. The digits are .56
high, which make them very readable. It is designed for chips like the 7219-
i.e., all the A's are tied together, all the B's are tied together and so on.
Has a total of 12 pins, 2 rows of 6 that are .600 apart. Plugs right in to
a 24-pin x .600 DIP socket. Mouser part number is 512-MSQ6941C for $4.24.

Will be glad to help with the project when you get to it.

Have a nice day.

Sid - W4EKQ

Archiver

Thanks very much Sid, all you engineers/techs are A-1 on this message
board! -Brian

--- In basicstamps@y..., Newzed@a... wrote:
> For bdalziel............
>
> Good morning
>
> Suggest you use the 4-digit multiplex module from Mouser. The
digits are .56
> high, which make them very readable. It is designed for chips like
the 7219-
> i.e., all the A's are tied together, all the B's are tied together
and so on.
> Has a total of 12 pins, 2 rows of 6 that are .600 apart. Plugs
right in to
> a 24-pin x .600 DIP socket. Mouser part number is 512-MSQ6941C for
$4.24.
>
> Will be glad to help with the project when you get to it.
>
> Have a nice day.
>
> Sid - W4EKQ