fuzzzy
Full Member level 3
Hi,
I made 2 different boards communicating by rs485. and controlled by PIC16f876.
they have the same power supply schemathics.the first has got 3 PCF8575 and the second one only a PCF8575 to control some leds.
i cant understand why the first one is stronger than second one. somethimes the second one will reset pcf8575 and lights all leds. it happens sometimes during work and when i switch off supply.The first one instead doesn't do it. there aren't very little differences between 2 boards apart number of pcf8575.
every couple of these boards have the same behaviour.
what do you tink will happen??
I made 2 different boards communicating by rs485. and controlled by PIC16f876.
they have the same power supply schemathics.the first has got 3 PCF8575 and the second one only a PCF8575 to control some leds.
i cant understand why the first one is stronger than second one. somethimes the second one will reset pcf8575 and lights all leds. it happens sometimes during work and when i switch off supply.The first one instead doesn't do it. there aren't very little differences between 2 boards apart number of pcf8575.
every couple of these boards have the same behaviour.
what do you tink will happen??
