On STM32F103, Encoder Input and Input capture at the same TIM3 available?

[kyuhyong]

Posted on June 07, 2015 at 03:36

Hello,

My STM32F103 is working as motor driver and work with pwm as an input runs at about 500hz or 2 ms duty. An incremental encoder is connected as a speed reference of the motor output.Pin connection is as follows.Encoder A --> PA6 (TIM3_CH1)Encoder B --> PA7 (TIM3_CH2)PWM1 in  --> PB0 (TIM3_CH3)PWM2 in  --> PB1 (TIM3_CH4)I already tested encoder function successful however input capture seems not to work.  I just want to know if this configuration is correct.Thanks,Kyu #pwm #encoder #stm32f103

[Tesla DeLorean]

Posted on June 07, 2015 at 03:56

There is only one counting element in the timer, you have it going up/down via the encoder. You can Input Capture those values, but it's probably not going to be helpful measuring unrelated signals.

You'll need to use a different timer.

[waaizkhan]

Posted on June 07, 2015 at 19:35

[jpeacock]

Posted on June 07, 2015 at 20:01 Since the timer is in encoder mode any capture has to be based on a change in the encoder timer, which in this case is either phase A or B depending on your setup.  You PWM measurements would have to be clocked from an encoder phase in order to work.   Jack Peacock