topic Re: S32k146 SDK dual-edge input capture in S32K

S32k146 SDK dual-edge input capture

Chandler_L — Sat, 18 Jan 2025 06:06:24 GMT

Hi NXP：

I am using the S32K146 for the first time and would like to set up a demo for dual-edge input detection. According to the manual, dual-edge detection requires configuring two channels. However, I would like to know if it's possible to detect the frequency and duty cycle of the input signal using just one channel. Could you please provide an SDK-driven demo for dual-edge detection and how to measure the input signal's frequency and duty cycle?

Thank you.

Re: S32k146 SDK dual-edge input capture

Senlent — Mon, 20 Jan 2025 02:14:45 GMT

Hi@LaiBighead

This is a demo I post before, you can take a look at this.

https://community.nxp.com/t5/S32K-Knowledge-Base/S32K1-Calculate-the-motor-speed-based-on-the-FTM/ta-p/1515933

Re: S32k146 SDK dual-edge input capture

Chandler_L — Tue, 21 Jan 2025 01:14:36 GMT

I'm glad to receive your reply. I have made some attempts with this case, and it was somewhat enlightening. However, when trying the dual-edge detection, I’m unsure when to obtain the Cnv values of CHn and CHn+1.

Re: S32k146 SDK dual-edge input capture

Chandler_L — Tue, 21 Jan 2025 03:08:52 GMT

双边沿检测功能已实现，但很奇怪，会一致卡住FTM4_CH2_Input_Detect函数里面，捕获通道频率设置为375Khz，给通道输入250Khz的PWM波；

Re: S32k146 SDK dual-edge input capture

Senlent — Tue, 21 Jan 2025 07:06:49 GMT

Hi@LaiBighead

双边沿输入捕获250KHz，一秒钟相当于中断差不多500K次，你说你这样用考虑过S32K146的性能吗？

通常电机控制中也就个10K或者20K，你这么高的速率它能处理的了吗。

Re: S32k146 SDK dual-edge input capture

Chandler_L — Wed, 22 Jan 2025 08:07:33 GMT

谢谢，问题已解决，祝您生活愉快