Three.sergei wrote:Think of the speed sensor basically a switch that switches once (or twice) per rotation.
sergei wrote:Normally speed sensor in the gearbox drives the speedo directly (older types were reed switches). Then the speedo feeds "normalized" speed signal to ECU.
I am not familiar with nissan speed sensors, but Toyota speed sensor is fed by 12V, and it generates a pulse every 180' degrees (it pulses twice over one rotation). The width does not matter. All you need is count rising edges of the pulses. The frequency of pulses will increase if you increase the speed and this is how it reads the speed. Think of it as counting how many pulses it outputs every second.
It is very similar to how CAM/Crank angle sensor outputs (it generates N-pulses every rotation). It does not really matter what type of sensor (optical, hall or simple reed switch), as those type of sensors will generate pulses per time type of output, where frequency of pulses will be dependant on rotational speed.
PWM is incorrect approach.
PWM is the only output the Link can provide.
I emailed Link yesterday. The only speedo I can drive with the link is one that uses a hall effect speed sensor, which are not very common. He was unable to specify a particular vehicle I could get one from. Aftermarket hall effect sensor speedos are more common. I do not want to buy a new aftermarket speedo.
He told me how to identify the hall effect sensors as opposed to the reluctor sensors.
Reluctor wires = ground, ground, signal.
Hall Effect wires = ground, power, signal.
Every 3 wire sensor I could find at Pick a Part was a reluctor I think I covered most makes.
I'm just going to stick a speedo face on a rev counter and get the link to use it as the speedo.
