The wheel speed pulse signal of the car is too narrow, and the sampling frequency of the equipment is too low to collect it. Is there any way to extend the pulse width?

小手冰凉WW

The wheel speed pulse signal of the car is too narrow, and the sampling frequency of the equipment is too low to collect it. Is there any way to extend the pulse width? [Copy link]

This pulse signal is only 0.08ms. It is too short.

小手冰凉WW

The second photo was taken with a sampling frequency of 10 kHz. The device I am using cannot capture it at all. Please help me.

chunyang

It is not difficult for an MCU with a higher main frequency to collect a pulse width of tens of uS. If you want to widen the pulse, if the interval between adjacent pulses is wide, you can use a monostable circuit. The pulse is only a trigger signal, and the output pulse width is determined by the time constant of the monostable circuit. If the interval between adjacent pulses is narrow, you can use a frequency divider to turn two or more pulses into one, and the pulse width will be greatly widened. However, if you pursue accuracy, it is better to use a suitable MCU or MPU to collect directly. As mentioned earlier, it is not difficult to collect a pulse width of tens of uS.

小手冰凉WW

chunyang posted on 2019-8-27 23:30 It is not difficult to collect pulse widths of tens of uS for MCUs with higher main frequencies. If you want to widen the pulse width, if the interval between adjacent pulses is wide, you can use a monostable circuit, ...

Thank you, I want to separate the wheel speed signal for other equipment to collect, without touching the original car's ECU. I will try the monostable circuit first. It's very strange. Our previous car collected wheel speed by directly connecting the wheel speed signal line. I don't know why the wheel speed pulse width of the new car suddenly became very narrow, which caused this problem. Thank you again!