Pax Writer
New Member
Hello all
The place where I work, we have some processors communicating by means of IR. They work with a simple protocol, in that every time a byte is transferred, it is sent a number of times (typically 100+). The receiving processor then calculates the number of correct transfers. If 70% of the signals had the same value, the command is considered valid.
Most of the time this works, but sometimes for inexplicable reasons, we get communications errors.
The two IR-circuits are placed 20-40cm apart.
The processor is an ATMEGA162V running at 7.3728MHz (crystal).
The IR-circuit is based on a TFDU4100 with 165 Ohms in series with the IR-LED, speed is 115kbit/sec.
Power supply is 5V
The PCBs are placed in an industrial environment with a lot of noise. We have previously had problems with airborne noise as well as noise coming from the power supply which also supplies 3-phase motors without any filtering than some big caps in the PCB's internal power supply. The PCB has basic noise protection which has removed most other errors we had on this PCB.
Could some noise still cause poor IR communications?
Are there any "usual suspects" I should be aware of in connection with IR-communications?
I hope you experts can help me out. Thanks in advance.
/Malmkvist
The place where I work, we have some processors communicating by means of IR. They work with a simple protocol, in that every time a byte is transferred, it is sent a number of times (typically 100+). The receiving processor then calculates the number of correct transfers. If 70% of the signals had the same value, the command is considered valid.
Most of the time this works, but sometimes for inexplicable reasons, we get communications errors.
The two IR-circuits are placed 20-40cm apart.
The processor is an ATMEGA162V running at 7.3728MHz (crystal).
The IR-circuit is based on a TFDU4100 with 165 Ohms in series with the IR-LED, speed is 115kbit/sec.
Power supply is 5V
The PCBs are placed in an industrial environment with a lot of noise. We have previously had problems with airborne noise as well as noise coming from the power supply which also supplies 3-phase motors without any filtering than some big caps in the PCB's internal power supply. The PCB has basic noise protection which has removed most other errors we had on this PCB.
Could some noise still cause poor IR communications?
Are there any "usual suspects" I should be aware of in connection with IR-communications?
I hope you experts can help me out. Thanks in advance.
/Malmkvist