SDK 3.4 Known Limitiations Encoder TIM pin clarification

[luke23]

Posted on March 24, 2014 at 23:49

Hi

In the PMSP single/dual FOC SDK v3.4 RELEASE NOTE it says:

3. Known limitations in v3.4

ENCODER speed sensor function: one Input Capture pin of the selected timer must be grounded, according to the remapping in use and this rationale: IC4 in case of TIM2, IC4 in case of TIM3, IC3 in case of TIM4, IC4 in case of TIM5;

I am using STM3210B-MCKIT (MB459) along with the supplied Shinano motor which has the capability of encoder feedback. In this setup, TIM2 would be used over MCU pins PA0-PA3, or in terms of peripherals TIM2 channels 1-4. According to the 'Known Limitations' then, it is required that PA3 (TIM2 Ch 4 (IC4)) is grounded. However I note that on that on the schematic diagram for the motor development kit (UM0426) that TIM2 Ch4 is not grounded - rather, it is used for analog voltage reading. In our application we use 3x hall snesors, but no encoder.  Would you kindly clarify the 'Known limitations' note, please? Perhaps the 'Known limitations' note should specify Hall Effect sensors, but without the encoder function?  I am perplexed.  Kindly clarify. Thanks Luke   #encoder-release-note-limitation

[Gigi]

Posted on March 31, 2014 at 10:04

Ciao Luke,

The limitation is only for Encoder and not affect the Hall sensors. Moreover the STM32F10B is a general purpouses board and so we can't setup it groundig a pin that can be reused for other purpouses. The Encoder managemet works even if this pin is used with a fixed voltage like in the evaluation board because the algorthm is sensible just to a rising or falling edge on that pin. But I suggest to avoid it if possible. Ciao Gigi

[Laurent Ca...]

The question has been moved from the section "Motor Control Hardware" to the "STM32 Motor Control" section (the question is about the STM32 MC SDK). 

Best regards