Interfacing/counting three Quadrature Encoder Inputs in Cortex M3 MCU

[vinuvspark]

want to connect three Linear encoders (2 phase each) to QEI in a Cortex M3. The Signal Frequency is maximum 170 Khz. Please suggest any suitable MCU.

[vinuvspark]

Thanks XiangJun Rong.

I was searching for any M3 or M4 MCUs with three Quadrature Encoder Inputs.

Is it available or should I go to Software Counter?

My expected frequency of QEI is 170 Khz.

Any help is appreciated.

 

[xiangjun_rong · Accepted solution]

Hi,

Okay, if you just want  M3 or M4 core processor, I suggest you consider Kinetis KV3x(Cortex-M4 core), the KV31 has 3 FTM modules, all of them can interface with Encoder.

This is KV31 Figure:

For KV11(Cortex-M0 core), this is KV11 FTM features:

Pls refer to Kinetis KV11 or KV31 from the link:

https://www.nxp.com/products/processors-and-microcontrollers/arm-microcontrollers/general-purpose-mc...

Hope it can help you

BR

Xiangjun Rong

[xiangjun_rong]

Hi,

currently, as you know that both the quadTimer and quadratute decoder modules can decode the Encoder signals,each quadTimer module can decoder ONE encoder signals.

The MC56F84789 has 2 quadTimer modules and ONE quadratute decoder module, so it can connect with 3 encoder, the quadratute decoder  has index and home signal besides the PhaseA/B signals.

This is link of MC56F84789:

https://www.nxp.com/products/processors-and-microcontrollers/additional-mpu-mcus-architectures/digit...

I think you can consider i.mxrt family for example i.mxrt1060, it has 4 quadTimer modules and 4 quadratute decoder module, in other words, it can interface with 8 encoder(incremental encoder with index and home signals).

https://www.nxp.com/products/processors-and-microcontrollers/arm-microcontrollers/i-mx-rt-crossover-...

You can consider also Kinetis KV family, for example KV56, it has 4 FTM module, the FTM1/FTM2 module support quadrature decoder, and it has one Quadrature Encoder/Decoder (ENC), so it can interface with 3 encoders.

https://www.nxp.com/products/processors-and-microcontrollers/arm-microcontrollers/general-purpose-mc...

If your application is auto, you can consider S32K or MPC56xx.

Hope it can help you

BR

XiangJun Rong