Seven Segment Flicker Issue

[Suraj143]

I'm multiplexing four sets of 12V common anode seven segments from a MCU.

The picture shows how I'm driving.The problem is when I replace the segments with LED's & make a giant segments I can see a slight flickering when multiplexing.

Refresh rate is 62Hz.

 

[Joe G]

have you tried upping the refresh rate higher, 100hz or more?

 

[KeepItSimpleStupid]

it's your programming. You have to do do inter-digit blanking. What does that mean? You do have to turn off the segment signals briefly before enabling the next digit.

So, it may not be flicker, but the previous on segments are "ghosted" to the next selected digit. Change th order for fun and see if looks different. Instead of 1,2,3,4 use 1,4,2,3 as the scanned digits.
or

display 8888 or 1111 and see if there is flicker. If there isn't then it's inter-digit blanking.

 

[Suraj143]

it's your programming. You have to do do inter-digit blanking. What does that mean? You do have to turn off the segment signals briefly before enabling the next digit.

So, it may not be flicker, but the previous on segments are "ghosted" to the next selected digit. Change th order for fun and see if looks different. Instead of 1,2,3,4 use 1,4,2,3 as the scanned digits.
or

display 8888 or 1111 and see if there is flicker. If there isn't then it's inter-digit blanking.

Very good reply.Helped a lot.I'll let you know.

 

[be80be]

it's your programming. You have to do do inter-digit blanking. What does that mean? You do have to turn off the segment signals briefly before enabling the next digit.

So, it may not be flicker, but the previous on segments are "ghosted" to the next selected digit. Change th order for fun and see if looks different. Instead of 1,2,3,4 use 1,4,2,3 as the scanned digits.
or

display 8888 or 1111 and see if there is flicker. If there isn't then it's inter-digit blanking.

Yes that's the number one reason you see what looks like flicker or ghosting. I say that hit the nail on the head.

 

[dr pepper]

Before you update the segments blank the entire display, this will improve things on a slow scan.