7 segment display connecting

RichardO

Joined May 4, 2013
2,273
Do you have to use that exact display? Using a multiplexed LCD would take fewer pins on the PIC. There is a Microchip application note on how to multiplex an LCD using regular port pins.

For instance, does a VIM-310 or VIM-332 work for you?
 

riddhi_shah

Joined Apr 3, 2017
8
Hi i have a 7 seg display http://www.farnell.com/datasheets/425221.pdf?_ga=2.195509480.533202882.1525861513-2134987385.1525861513
my question is what is the best way to connect it with PiC microcontroller?
Which PIC controller you are using? Why can't you just connect the wires from 7 seg display to controller and code using MPLAB or MicroC and display and edit for fun, here is a link that I usually used, may this help. Or I am missing something:rolleyes:
https://www.exploreembedded.com/wiki/Interfacing_Seven_Segments_with_PIC16f877a
 

Ian Rogers

Joined Dec 12, 2012
660
LCD panels need a duty cycle... The LCD segments are continually updated.. Its easier for a specialized chip to do this..

LED types are different!!
 

JohnInTX

Joined Jun 26, 2012
3,798
Which PIC controller you are using? Why can't you just connect the wires from 7 seg display to controller and code using MPLAB or MicroC and display and edit for fun, here is a link that I usually used, may this help. Or I am missing something:rolleyes:
https://www.exploreembedded.com/wiki/Interfacing_Seven_Segments_with_PIC16f877a
That's for an LED not LCD display ;)
@i.do.useless.stuff
Using a separate LCD driver is probably easier from a programming standpoint but also consider using a PIC with a built-in LCD driver. Your display has 29 segments and 1 backplane. To drive all of those with a PIC would require one with 29 LCD drive pins in the 'static' LCD mode i.e. one backplane. Something like a PIC16LF1904 or 1907 would do it and they come in a 40 pin DIP for playing around. There are a bunch of other alternatives that you can explore using the parametric search on microchip.com. Look for the column called 'Segmented LCD Display' and select a part with at least 4X the number of segments you want to use ( you might not need some of the symbols-tie those segments to the backplane). Look for 4X the segments (29*4= 116 minimum because Microchip specifies the max number of segments supported using up to a 1/4 multiplex scheme.)

Pick something up to date with decent debug support and maybe an evaluation board. There are also current 18F parts with LCD drivers as well. Older midrange stuff like PIC16F946 are OK but lack good debugging support and are more expensive as well.

Note that your programming will become a bit more involved with this approach. Instead of writing a 0x7, 0x1 to some peripheral to display 71, you have to deconstruct each individual segment in each digit and poke a '1' into the LCD output register. It's not particularly difficult but definitely more work.

Good luck!
http://www.microchip.com/wwwproducts/en/PIC16LF1907
 
Last edited:

shteii01

Joined Feb 19, 2010
4,667
You can connect it directly.
You may or may not have enough pins to light up all the led.
You may or may not have enough current to have the led at the same brightness (may need resistors to control the current supplied to each led).
 

jbeng

Joined Sep 10, 2006
55
The Varitronix VI-302 is an LCD display. It is NOT an LED module.
https://www.digikey.com/products/en?mpart=VI-302-DP-FC-S

It could be directly connected to a microcontroller, but as JohnInTX said, it would require 30 pins (29 segment pins and a backplane pin). Use a chip designed to drive a numeric LCD (like the one I mentioned previously) and your project will go a lot easier.
 

Thread Starter

i.do.useless.stuff

Joined May 9, 2018
3
That's for an LED not LCD display ;)
@i.do.useless.stuff
Using a separate LCD driver is probably easier from a programming standpoint but also consider using a PIC with a built-in LCD driver. Your display has 29 segments and 1 backplane. To drive all of those with a PIC would require one with 29 LCD drive pins in the 'static' LCD mode i.e. one backplane. Something like a PIC16LF1904 or 1907 would do it and they come in a 40 pin DIP for playing around. There are a bunch of other alternatives that you can explore using the parametric search on microchip.com. Look for the column called 'Segmented LCD Display' and select a part with at least 4X the number of segments you want to use ( you might not need some of the symbols-tie those segments to the backplane). Look for 4X the segments (29*4= 116 minimum because Microchip specifies the max number of segments supported using up to a 1/4 multiplex scheme.)

Pick something up to date with decent debug support and maybe an evaluation board. There are also current 18F parts with LCD drivers as well. Older midrange stuff like PIC16F946 are OK but lack good debugging support and are more expensive as well.

Note that your programming will become a bit more involved with this approach. Instead of writing a 0x7, 0x1 to some peripheral to display 71, you have to deconstruct each individual segment in each digit and poke a '1' into the LCD output register. It's not particularly difficult but definitely more work.

Good luck!
http://www.microchip.com/wwwproducts/en/PIC16LF1907

Really helpful. Thanks. I knew that i could use the driver, but i didn't like that approach so i was looking for something better that i don't know of.
 
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