AnsweredAssumed Answered

no filtering of timer inputs in output compare mode

Question asked by karakaya.mehmet on Jun 11, 2012
surucu.jpgI have designed a brushless servo motor driver with F103

I use Timer 4 in encoder mode and connect motor encoder to CH1 and CH2

at the same time for changing UVW phases I compare timer value with 24 constant numbers
and change phases according to table

for doing this I set CH1 and CH2 of Timer as compare outputs
I dont set alternate function to the CH1 and CH2 pins becouse they are connected to encoder as well
I only enable compare interrupts so I can detect end of one phase and beginning of other phase

however this time I cannot filter encoder inputs becouse as I said I defined CH1 and CH2 as output for comparing

and as a result there are glitches in encoder signals - which I cannot filter and corrupts the encoder value - which makes "hitting  sound " as the motor turns 

what do you advise me to do ? 
( I designed CH3 and CH4 as some other functions thats why I am looking for another ( cheaper )  solution otherwise I must reorder the PCB )