Thank you for your prompt response regarding the quadrature decoder capabilities of the RT1170. I understand from your explanation that the integrated decoder only supports x4 mode and lacks hardware support for x2 mode.
You suggested the possibility of using Signed-Count Mode, dividing the task to separately calculate rising and falling edges, to achieve the x2 functionality. However, based on my understanding of Signed-Count Mode and differential X2, I have reservations about the feasibility of this approach.
My understanding of differential x2, also known as double edge detection, involves counting both the rising and falling edges of a single phase. A typical rotary encoder outputs two channels, A and B, which are 90 degrees out of phase, facilitating direction detection. By counting both edges of one quadrature signal, we effectively double the encoder's resolution. For instance, an encoder with 100 pulses per revolution (PPR) on one channel can achieve 200 detectable events per revolution by utilizing differential x2.
Additionally, as illustrated in the attached diagram, it is necessary to combine both Phase A and Phase B to ascertain directional changes. The implementation of Signed-Count Mode in conjunction with software appears to present significant challenges.
I look forward to your insights or alternative solutions that could accommodate the differential x2 within the constraints of the RT1170's hardware capabilities.
Hi @chaseshen ，
Thanks for your interest in NXP MIMXRT series.
As you can see, the RT1170's Quadrature decoder integrated only supports x4 mode, and does not provide support for x2 mode at the hardware level.
But in your usage scenario, using Signed-Count Mode may be helpful.
Splitting it in two, one to calculate the rising edge and one to calculate the falling edge, should be able to achieve the x2 you describe.
Best regards,
Gavin
Thank you for your prompt response regarding the quadrature decoder capabilities of the RT1170. I understand from your explanation that the integrated decoder only supports x4 mode and lacks hardware support for x2 mode.
You suggested the possibility of using Signed-Count Mode, dividing the task to separately calculate rising and falling edges, to achieve the x2 functionality. However, based on my understanding of Signed-Count Mode and differential X2, I have reservations about the feasibility of this approach.
My understanding of differential x2, also known as double edge detection, involves counting both the rising and falling edges of a single phase. A typical rotary encoder outputs two channels, A and B, which are 90 degrees out of phase, facilitating direction detection. By counting both edges of one quadrature signal, we effectively double the encoder's resolution. For instance, an encoder with 100 pulses per revolution (PPR) on one channel can achieve 200 detectable events per revolution by utilizing differential x2.
Additionally, as illustrated in the attached diagram, it is necessary to combine both Phase A and Phase B to ascertain directional changes. The implementation of Signed-Count Mode in conjunction with software appears to present significant challenges.
I look forward to your insights or alternative solutions that could accommodate the differential x2 within the constraints of the RT1170's hardware capabilities.
