Need help with 873M ultrasonic sensor
 

Hey everybody, rookie here.

We have been working with a prototype robot because we are a new team and we just ordered a slew of parts from firstchoicebyandymark.com and among them was a Ultrasonic sensor (873M-D18AV300-D4) but it seems like there is no documentation of anyone using this sensor on a FRC bot and the manual from the company (linked here) is not much help. It also seems that the specs for the sensor says it needs 15-30V of power but the RoboRIO analog input's only provide 5V.

Does anyone know if this is usable with the RoboRIO and how we should wire it correctly? Has anyone used this sensor before?

Thanks in advance,

D.C.

Re: Need help with 873M ultrasonic sensor
 

Just by glancing at the spec sheet it would appear that these aren't going to be plug and play devices for the roboRIO, you will need to add some circuitry to get this to work.

Re: Need help with 873M ultrasonic sensor
 

Last year's rules allowed a custom circuit to be powered from a PCM port. The PCM may be configured to provide 24V. If you are not using pneumatics, or are using 24V solenoid valves, this may be an alternative, provided the rules don't change. Otherwise, I'd recommend a COTS DC supply to give you the voltage boost - you can do this for much less than the cost of a PCM.
As it outputs analog 0-10V, it looks like you will need a voltage divider (that is, two resistors in series from the sensor output to ground, with the output being between the resistors) to get the output analog level to the level of the roboRIO analog inputs. Unless you have time to work with this a bit before build season, it is probably better to put this on the back shelf to deal with after competition, for next year; if you need an ultrasonic sensor, there are quite inexpensive ones available at robotshop.com and a host of other suppliers. If you want short range (< 1 ft), infrared is usually an easier find than ultrasonic.