Electronics > Beginners
9-bit Addressable Latch Required
<< < (3/4) > >>
Ian.M:
Have you looked at the TPIC6C595 I suggested?   If you don't mind the 9th LED briefly flickering during updates (which could be so fast the flicker would be essentially invisible), you can drive the 9th LED MOSFET from the same I/O pin as data in to the  TPIC6C595 and just set the desired level immediately after clocking out the 8 bits, which gets it down to only 3 I/Os.

Its unfortunate that Camden Boss don't offer a 5V version of the buttons.
james_s:
Can you use a shift register? You can chain a pair of 74HC595's to get 16 bits and you don't have to use them all.

You could also use any number of different 8 bit latches or decoders and run the 9th LED directly from one of the uC pins.
JS:

--- Quote from: james_s on July 08, 2018, 04:55:02 pm ---Can you use a shift register? You can chain a pair of 74HC595's to get 16 bits and you don't have to use them all.

You could also use any number of different 8 bit latches or decoders and run the 9th LED directly from one of the uC pins.

--- End quote ---
That's the idea I was missing, I knew I was missing something as simple and efficent as that but I couldn't get it!

JS

boB:

--- Quote from: james_s on July 08, 2018, 04:55:02 pm ---Can you use a shift register? You can chain a pair of 74HC595's to get 16 bits and you don't have to use them all.

You could also use any number of different 8 bit latches or decoders and run the 9th LED directly from one of the uC pins.

--- End quote ---

Something like this is good.  AND, if you don't want to use 2 of them and 8 of the bits are going to be latched "somehow", maybe you could use the processor bit itself that is going into the 595 as the 9th bit ?  As long as they aren't written too often, you probably wouldn't notice that 9th LED being shortly turned on when 1's are coming out and into the shift register ?

Fun problem !

boB
Ian.M:
As I said 12 hours ago: TPIC6C595 + 1 MOSFET.   Its an 8 bit shift register that's controlled like a 74HC595, but has 30V 100mA open drain outputs.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod