Hi All
I made and LED panel that gets data through a GPRS modem once every 10 minutes, then writes this data to the panel. Hardware wise I made every precaution to avoid noise like having ferrite beads on all wires coming in and out of the boards including power supply lines and 2 separate power supplies, a linear regulator for the drivers and control with a separate SMPS for the LEDs themselves. Data is being sent to each display panel block using RS-485 and used solid ground plane for all the boards.
since the data goes to the constant current led drivers serially. is there away to know that the data was clocked correctly into the registers?
I had one thought to clock the data into shift registers 5 times then read back the data, if the last 4 times data was correct then there is a good probability that the fifth one is correct, then accept it, otherwise clock the data five times more. But this approach doesn't guarantee that the displayed data is correct.
Another thought since the data arrives once every 10 minutes to be displayed, I could keep refreshing the data every 1/2 second say in case corrupted data was occasionally clocked for some reason like power glitch. This way the erroneous reading will be shown for a very short time saving embarrassment.
Do you have any other thoughts that can make my Panel close to perfection?
Mahmood