635 text to screen problems


New member
Hi there...

I sometimes make multiple calls in a row to the lcd in order to print things to the screen. Occassionaly lines of text are missing. I've tried to remedy this situation by creating a semaphor around send_packet and adding a delay of 50 ms in there also before unlocking.

I know that it is recommended to wait for the packet to be acknowledged before sending the next one but is there anyway to avoid this or is there a guaranteed time delay to make it work 100% of the time?

The current semaphor/50ms set-up I have only created one missing line of text after observing 2 to 3 hours of text swapping on the LCD, but since this will be sold to a consumer, it should be a requirement for this to work.

So should i wait for the ack or is there still a quick method around this using delays?

Thanks for the help!
Looking for additional LCD resources? Check out our LCD blog for the latest developments in LCD technology.

CF Tech

Officially you should wait for the ACK.

I would think that 50mS would be plenty of time for the the line to be displayed, but I have never timed the code.
USB LCD Displays - Graphic and Character LCDs with a Keypad