Can the MC14489 Multiplexor work with BS1?

ccjung

Hi everyone,

After some development with the BS2 for a temperature controller I am working on, I am looking to move to the BS1 for production costs.

I have searched quite a few times and on google and have found very little on the subject.

Does anyone know if the MC14489 Multiplexor for 7 Segment LED will work with the BS1?
Thanks in advance,

Chris

·

Chris Savage

Chris,

·· It will work, but you will have to bit-bang the data since there is no SHIFTIN/SHIFTOUT command on the BS1.· You can write a subroutine to handle those details and just call that when you need to send data to the display.


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Chris Savage
Parallax Tech Support
csavage@parallax.com

ccjung

Thank you Chris,

This also begs the question, would it be better with a 16x2 Parallel LCD?

Mike Green

If you were using a BS2, I'd recommend the parallel LCD. It's compact, low-power, there's lots of code already available for it. The problem is that it uses a lot of pins which are scarce on the BS1. Best choice for everything but cost is a serial LCD.

Chris Savage

Mike is right...If you want to go with the LCD you should use the Serial Display...1 I/O line is used and the BS1 has a command to handle these.· Just as a matter of point of wouldn't really be that hard to talk to an SPI device like the MC14489 if you wrote the subroutine, since you only need to do the bit-bang routine once.· Basically you're going to activate the CS line, and then generate 8 clock cycles (LOW-HIGH-LOW) while generating the output bytes by shifting them or picking them from the variable.· You could probably work it out, or find a routine for the BS1 that talked to something else SPI like the DS1302 or DS1620.

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Chris Savage
Parallax Tech Support
csavage@parallax.com