Hello!
I'm using Raspberry Pi 2 in a production environment. I'm also using GPIO on the Pi. There are some problems with inputs and noise. Input signals are
24 V DC and they are driving the optocoupler LED trough resistor. Optocoupler then just switches gpio pin to ground. Presence of noise sometimes triggers Pi input trough optocoupler. For now I solved this issue inside program but if it's posible I want to further solve it with hardware. The noise has a pretty decent amplitude about 10 V and it last for about 1 ms. This was measured before we changed the communication (GPIO) cable between the GPIO board and PLC with shielded one. Noise is produced while TIG welding on the same machine.
For now I solved the problem by software and it works well, but is there any option to do that with hardware? For instance, even the PLC had some troubles with noise and they were also solved by the program, so i wonder if it's even possible to effectively and simple filter this out by hardware.
I just used TLP521 and 3k3 resistor in series with diode. I knew that this is not the best option, so just to be safe for other projects (even if it won't help for this case), how the optocoupler driving circuit should be made?
I'm using Raspberry Pi 2 in a production environment. I'm also using GPIO on the Pi. There are some problems with inputs and noise. Input signals are
24 V DC and they are driving the optocoupler LED trough resistor. Optocoupler then just switches gpio pin to ground. Presence of noise sometimes triggers Pi input trough optocoupler. For now I solved this issue inside program but if it's posible I want to further solve it with hardware. The noise has a pretty decent amplitude about 10 V and it last for about 1 ms. This was measured before we changed the communication (GPIO) cable between the GPIO board and PLC with shielded one. Noise is produced while TIG welding on the same machine.
For now I solved the problem by software and it works well, but is there any option to do that with hardware? For instance, even the PLC had some troubles with noise and they were also solved by the program, so i wonder if it's even possible to effectively and simple filter this out by hardware.
I just used TLP521 and 3k3 resistor in series with diode. I knew that this is not the best option, so just to be safe for other projects (even if it won't help for this case), how the optocoupler driving circuit should be made?