I’ve connected the Sharp range finder (Sharp GP2Y0A02YK0F) to the Mini-Maestro’s Analog input on channel 11.
It’s powered using the Vout 5v from the on board regulator and the board is being powered via USB.
However I’m seeing a variance in the output voltage of 0.1v over 500ms when the target object is stable at a fixed distance that is within the operating distance, I see this variance at any distance object.
In the documentation of the sensor it recommend using a capacitor between Vcc and Gnd, would this help with stabalising the variance or is it just a characteristic of the device?
In general, some variance is not unexpected. Those sensors also draw large amounts of current in bursts, which could cause some additional variation in the sensor’s output voltage. Adding a capacitor between GND and Vcc (preferably, as close to the sensor pins as you can get) should help cut down on that variance. Also, it is generally good practice to average the readings from sensors like these, and it should give you better results.
thanks for the reply, yes I am definitely going to average the readings, when you say “as close to the sensor pins” - I’m taking from this you mean on the sensor side of the connection rather than the servo boards connection.
e.g.
Controller ~ Cap Sensor
g ----------------->x----->g
Vo ----------------->x----->Vi
Vi ------------------------->Vo
Putting it right at the sensor is best, but if it is easiest to put it where the sensor cable plugs into the Maestro, you might start with that as that could be good enough. Do you have access to an oscilloscope you could use to see what the sensor signal actually looks like under various conditions?
