module Ultrasonic: sig .. end
Ultrasonic sensor. Convenience functions to interact with the
ultrasonic sensor through the I2C protocol.
type
Represent an initialized ultrasonic sensor connected to a
given port.
val make : 'a Mindstorm.conn -> Mindstorm.Sensor.port -> t
make conn port initialize the sensor on port port as
being an ultrasonic one.
val set : ?check_status:bool ->
t ->
[ `Event
| `Meas
| `Meas_cont
| `Meas_interval of int
| `Off
| `Reset
| `Scale_div of int
| `Scale_mul of int
| `Zero of int ] -> unit
Ultrasonic.set us cmd set the state or parameters for the
ultrasonic sensor
us.
cmd may be:
`Off: turns the ultrasonic sensor off.`Meas: single shot command. In this mode, the
ultrasonic sensor will only make a new measurement every
time the command byte is send to the sensor. The sensor
will measure distances for up to 8 objects and save the
distances within the `Byte0 .. `Byte7 variables.`Meas_cont Continuous measurement command. This is the
default mode, where the sensor continuously makes new
measurement with the specified interval (see
`Meas_interval below).`Event: Event capture command. Within this mode the
sensor will measure whether any other ultrasonic sensors are
within the vicinity. With this information a program can
evaluate when it is best to make a new measurement which
will not conflict with other ultrasonic sensors.
`Meas_interval t: set continuous measurment interval.`Zero z: set the actual zero.`Scale_mul m: set the actual scale factor.`Scale_div d: set the actual scale divisor.
`Reset: resets the ultrasonic sensor.
check_status : check the return status. Exceptionally,
the default is true because the sensor needs to time to
set itself up anyway and this avoids Mindstorm.Buffer_full
errors if we try to get values from the sensor.
val get : t ->
[ `Byte0
| `Byte1
| `Byte2
| `Byte3
| `Byte4
| `Byte5
| `Byte6
| `Byte7
| `Meas_interval
| `Scale_div
| `Scale_mul
| `Zero ] -> int
Ultrasonic.get us var returns the content of the variable
var on the sensor (detailed underneath). All values are
between 0 and 255. Communication errors will be reported by
raising
Error Bus_error; your application should be ready
to handle such exceptions.
`Byte0 .. `Byte7 are the 8 variables containing the
distances measured with the `Meas or `Meas_cont command
(in centimeters).
`Meas_interval returns the interval (in 0.01 sec)
between two consecutive measurments when the sensor is in
continuous measurment (command `Meas_cont).
`Zero returns the value of the actual zero (settable
with the `Zero command).
`Scale_mul (resp. `Scale_div) return the current
scaling factor (resp. divisor). It is settable with the
`Scale_mul (resp. `Scale_div) command.
val get_state : t ->
[ `Event | `Meas | `Meas_cont | `Off | `Reset ]
get_state us get the current state of the ultrasonic
sensor us.
