All Commands

Sleep(milliseconds)

Pauses script execution for the specified number of milliseconds.

Sleep(1000)   # Pauses for 1 second

SleepRandom(lowMilliSec, highMilliSec)

Pauses for a random interval between the two specified millisecond values.

SleepRandom(1000, 5000)

Servo(servoPort, position)

Move a servo to a specified position (1–180).

Servo(D14, 25)

SetServoMin(servoPort, position) / SetServoMax(servoPort, position)

Set hard limits for a servo so it never moves below the minimum or above the maximum. Positions are in the 1–180 range.

SetServoMin(D14, 40)
SetServoMax(D14, 100)

ServoSpeed(servoPort, speed)

Set the speed for a servo (or PWM) when moving between positions. Speed values range from 0 (fastest) to 10 (slowest).

Important: On first use, set an initial Servo() position before calling ServoSpeed(); otherwise the system may assume the current position is 0 and behave unexpectedly. After initialization, set ServoSpeed() before calling Servo().

Servo(D14, 20)        # initialize servo position first
ServoSpeed(D14, 2)     # then set speed

ServoSpeedRandom(servoPort, lowSpeed, highSpeed)

Apply a random servo speed between the specified values (0 = fastest, 10 = slowest). Same initialization notes as ServoSpeed().

ServoSpeedRandom(D14, 1, 4)

ServoUp(servoPort, count) / ServoDown(servoPort, count)

Increment or decrement the servo's current position by the specified amount. Final position is clamped to 1–180.

ServoUp(D14, 1)
ServoDown(D14, 1)

ServoRandom(servoPort, lowPosition, highPosition)

Move the servo to a random position between lowPosition and highPosition (1–180).

ServoRandom(D14, 10, 20)

Release(servoPort) / ReleaseAll([boardIndex])

Release a single servo or release all servos so they no longer hold position. BoardIndex is optional and selects the EZ-B board when multiple boards are used.

Release(D14)
ReleaseAll()          # release all servos on default board

PWM(digitalPort, speed) / GetPWM(digitalPort) / PWMRandom(digitalPort, lowSpeed, highSpeed)

Set or read PWM (Pulse Width Modulation) on a digital port. PWM simulates an output voltage (scaled between 0–5V). Values are percentages from 0 to 100.

PWM(D14, 90)
$x = GetPWM(D14)
PWMRandom(D14, 10, 90)

Move(servoPort, "forward" / "stop" / "reverse")

Set motion for modified servos that support directional movement.

Move(D14, "forward")

Set(digitalPort, ON|OFF|TRUE|FALSE) / SetRandom(digitalPort) / ToggleDigital(digitalPort)

Set a digital port state, pick a random on/off state, or toggle the port.

Set(D2, OFF)
SetRandom(D2)
ToggleDigital(D2)

Digital_Wait(digitalPort, ON|OFF, [delay MS])

Pause execution until a digital port reaches the requested state. Optional delay controls how often the port is checked (milliseconds).

Digital_Wait(D12, ON)
Digital_Wait(D12, ON, 50)

ADC_Wait(adcPort, HIGHER|LOWER|EQUALS, value, [delay MS])

Pause until an ADC port is higher/lower/equals the specified value. Optional delay controls polling interval.

ADC_Wait(ADC0, HIGHER, 50)
ADC_Wait(ADC0, HIGHER, 50, 50)

ADC_Wait_Between(adcPort, low, high, [delay MS])

Pause until an ADC port value falls between low and high (inclusive). Optional delay controls polling interval.

ADC_Wait_Between(ADC0, 20, 50)
ADC_Wait_Between(ADC0, 20, 50, 50)

GetADC(port) / GetADC12(port) / GetDigital(port)

Read analog and digital values. GetADC returns 8-bit ADC; GetADC12 returns 12-bit ADC. GetDigital returns 0 or 1 for digital ports.

$a = GetADC(ADC0)
$b = GetADC12(ADC0)
$d = GetDigital(D0)

Forward([speed], [milliSeconds]) / Reverse([speed], [milliSeconds]) / Stop()

Control movement via a configured Movement Panel. Provide optional speed (0–255) and duration in milliseconds.

Forward()
Forward(200)
Forward(255, 5000)

Reverse()
Reverse(200)
Reverse(255, 5000)

Stop()

Left([speed], [milliSeconds]) / Right([speed], [milliSeconds])

Turn the robot left or right using the Movement Panel. Speed is 0–255. Optionally specify milliseconds to turn.

Left()
Left(200)
Left(200, 5000)

Right()
Right(200)
Right(200, 5000)

Drone and Advanced Movement: Up([ms]) / Down([ms]) / RollRight([ms]) / RollLeft([ms]) / TakeOff() / Land() / DroneEmergency()

Use Movement Panel servo settings for drone actions. Provide optional durations in milliseconds. DroneEmergency() attempts to reset or power down the drone immediately—assign this to a dedicated joystick button for safety.

Up()
Up(1000)

Down()
Down(1000)

RollRight()
RollRight(1000)

RollLeft()
RollLeft(1000)

TakeOff()
Land()

DroneEmergency()

Movement_Wait("forward" | "reverse" | "stop" | "left" | "right")

Pause until a movement command from the Movement Panel is executed. This waits for the movement state, even if the command originates from another running script.

Movement_Wait("FORWARD")

WaitForServoMove(servoPort, [timeout MS])

Wait until the specified servo moves to a new position. Unlike Servo_Wait (which waits for a specific condition), this returns when the servo position changes. Optionally specify a timeout in milliseconds.

WaitForServoMove(D0)
WaitForServoMove(D0, 1000)

Ping_Wait(triggerPort, echoPort, HIGHER|LOWER|EQUALS, distance)

Pause until the Ping sensor reading is higher/lower/equals the specified distance. Trigger and echo are digital ports.

Ping_Wait(D3, D4, HIGHER, 50)

EZ-B Speaker (onboard)

Use these commands to speak via the EZ-B v4 speaker. They run in the background unless the Wait variants are used.

SayEZB("Hello, I am a robot")            # non-blocking
SayEZB("Speak on EZB #2", 1)             # specify EZ-B index 0–4

SayEZBWait("Hello, I am a robot")        # blocks until finished
SayEZBWait("Speak on EZB #2", 1)

SSML variants accept formatted SSML rather than plain text:

SaySSMLEZB("...")
SaySSMLEZBWait("...", 1)

StopEZBAudio()

PC TTS and Audio

Speak using the PC sound card. Background commands are non-blocking; Wait variants block until speech completes.

Say("Hello, I am a robot")            # non-blocking via PC audio
SayWait("Hello, I am a robot")         # blocks until finished

SaySSML("...")
SaySSMLWait("...")

SpeakStop()                            # stops PC TTS audio

SpeakRSS and SpeakTwitter read remote content aloud:

SpeakRSS("https://rss.cbc.ca/lineup/world.xml")
SpeakRSS("https://rss.cbc.ca/lineup/world.xml", 3)
SpeakRSSDescription("https://rss.cbc.ca/lineup/world.xml", 3)
SpeakTwitter("EZ_Robot")
SpeakTwitter("EZ_Robot", 3)

SpeakVolume(30)

EZ-B Speaker Volume

Set or get the EZ-B v4 speaker volume. Valid ranges: 0 (quiet) to 100 (loud) and up to 200 for overdrive.

SetVolume(50)
SetVolume(100, 1)   # set on EZ-B index 1
$x = GetVolume()

PlayAudio(filename) / StopAudio()

Play audio files (MP3 or WAV) through the default audio device.

PlayAudio("c:\\temp\\myAudio.mp3")
StopAudio()

SoundNote(note, lengthMS, [signalType])

Play a musical note on the EZ-B v4 speaker for the specified milliseconds. Optional signal types: Sine, Square, Triangle, Pulse, Sawtooth, WhiteNoise, GaussNoise, DigitalNoise.

SoundNote("C2", 1000)
SoundNote("C2", 1000, "Square")

MP3Trigger Shield Commands

Control the MP3 Trigger Shield over a digital serial port. Typical baud rates are 38400.

MP3TriggerPlayTrack(d0, 38400, 1)
MP3TriggerPlayTrack(d0, 38400, 1, 3000)    # optional pause disables SpeechRecognition for given ms
MP3TriggerVolume(d0, 38400, 20)            # 0 = loudest, 255 = quiet
MP3TriggerPlayRandomTrack(d0, 38400, 1, 10)
MP3TriggerNext(d0, 38400)
MP3TriggerPrev(d0, 38400)
MP3TriggerStop(d0, 38400)

I2CClockSpeed(boardIndex, rate)

Set the I2C clock speed on an EZ-B board. Default is 100000 (100 kHz). Many devices support up to 400000 (400 kHz).

I2CClockSpeed(0, 100000)
I2CClockSpeed(0, 400000)

I2CWrite(boardIndex, deviceAddress, data...)

Start I2C, write data (hex, string or decimal), then stop. Device address must be in 0x00 format.

I2CWrite(0, 0x09, 0x02, 0x05, 0x06)
I2CWrite(0, 0x09, 244)
I2CWrite(0, 0x09, "This is text" + $variable)

I2CWriteBinary(boardIndex, deviceAddress, variable)

Send binary data from an array variable to the device over I2C.

I2CWriteBinary(0, 0x09, $variable)

I2CRead(boardIndex, 7bitDeviceAddress, bytesToExpect) / I2CReadBinary(..., variable)

Read ASCII or binary bytes from an I2C device. Specify the 7-bit hex address and how many bytes to read.

$val = I2CRead(0, 0x5e, 2)
I2CReadBinary(0, 0x5e, 2, $variable)

SendSerial(digitalPort, baudRate, data...)

Send data over a digital port configured as serial (no input buffer). Data may be hex, string or decimal.

SendSerial(d0, 9600, 0x00, 0x04, 0x05)
SendSerial(d0, 9600, 244, 200, "a")
SendSerial(d0, 9600, "This is text")
SendSerial(d0, 9600, "Hello " + $name)

SendUDP(hostname, port, data...)

Send UDP packets to a given hostname and port. Data may be hex, string or decimal.

SendUDP("192.168.0.1", 21, "HelloWorld")
SendUDP("192.168.0.1", 21, 0x20, 0x21, 0x22, 0x30)
SendUDP("192.168.0.1", 21, 0x20, 0x21, 0x22, "Hello")

UART (EZ-B Peripheral UARTs)

Initialize and use the hardware UARTs on the EZ-B v4. UART receive buffers are 5,000 bytes. Ports: 0 (expansion connector), 1 (D5/D6), 2 (D18/D19).

UARTInit(0, 0, 9600)
UARTAvailable(0, 0)                # bytes available to read
UARTRead(0, 0, 10)                 # read ASCII bytes
UARTReadBinary(0, 0, 10, $variable)# read binary bytes into an array
UARTReadAvailable(0, 0)            # read all available ASCII bytes
UARTWrite(0, 0, "hello world")
UARTWriteBinary(0, 0, $variable)

See the UART Ports section below for TX/RX pin mappings.

PC Serial (ComOpen / ComClose / ComWrite / ComRead...)

Open and interact with local PC serial ports. ComOpen begins buffering incoming data (128 KB buffer).

ComOpen("com1", 9600)
ComAvailable("com1")
$line = ComReadLine("com1")
ComWrite("com1", "this is data")
ComClose("com1")

ComReadBinary / ComWriteBinary allow binary data transfer via arrays.

HTTPGet(url)

Perform an HTTP GET and return the response contents.

HTTPGet("https://192.168.0.10/decoder_control.cgi?command=35&onestep=5&user=admin&pwd=admin")
$temp = HTTPGet("https://192.168.0.15/GetTemperature.cgi")

Exec(exeOrBat, [parameters]) / Browser(url)

Execute a local program or open the default browser to a URL.

Exec("C:\\Windows\\notepad.exe")
Exec("C:\\Windows\\notepad.exe", "C:\\MyFile.txt")
Browser("https://www.google.com")

File operations

Read, write, append, delete and inspect files on the computer.

FileDelete("c:\\temp\\mylog.txt")
FileWrite("c:\\temp\\mylog.txt", "MyVariable: " + $x)       # appends text (no newline)
FileWriteLine("c:\\temp\\mylog.txt", "Servo Position: GetServo(d2)")  # append newline
FileReadClose("c:\\temp\\mylog.txt")    # close after reading
FileReadReset("c:\\temp\\mylog.txt")    # reset read position
$fileExists = FileExists("c:\\temp\\mylog.txt")
$fileEnd = FileReadEnd("c:\\temp\\mylog.txt")
$char = FileReadChar("c:\\temp\\mylog.txt")
$line = FileReadLine("c:\\temp\\mylog.txt")
$contents = FileReadAll("c:\\temp\\mylog.txt")
$randomLine = FileReadLineRandom("c:\\temp\\mylog.txt")

ControlCommand(windowName, ControlCommandParameter, [values...]) — alias: CC(...)

Send commands to named controls in your project. Use the script editor's "Cheat Sheet" tab to view each control's available parameters and expected values.

ControlCommand("ADCGraph", pauseOn)
ControlCommand("SoundBoard", Track_3)
ControlCommand("ScriptManager", ScriptStart, "MyScript")
ControlCommand("SpeechRecognition", PauseMS, 3000)

# shorthand alias
cc("Auto Position", AutoPositionAction, "Action Name")
cc("Auto Position", AutoPositionFrame, "Frame Name")
cc("Auto Position", AutoPositionFrame, "Frame Name", 50, 3)

GetControlValue(windowName, ControlCommandValues)

Retrieve a value from a named control. See each control's Cheat Sheet for valid parameters.

$x = GetControlValue("ADC Graph", "pause")

Comments, Labels and Goto

Standard constructs for controlling script flow.

# single-line comment
:My_Label
Goto(My_Label)
Return()    # returns from a Goto()

If / ElseIf / Else / EndIf

Supports comparisons (=, <, >, <=, >=, !=) and logical operators AND, OR. Close condition blocks with EndIf.

If(GetDigital(D0) = 1)
  Print("One")
EndIf

If ($Day = 2 AND $Hour = 3)
  Print("Hello")
EndIf

If (GetServo(D5) > 20 OR ($x >= 3 AND $y < 2))
  Print("Yup!")
EndIf

Repeat loops

REPEAT/ENDREPEAT is similar to FOR; REPEATUNTIL and REPEATWHILE provide condition-based loops.

REPEAT($x, 0, 5, 1)
  Print("x=" + $x)
ENDREPEAT

REPEATUNTIL($second = 30)
  Print("Second=" + $second)
  Sleep(500)
ENDREPEAT

REPEATWHILE($second <= 50)
  Print("Second=" + $second)
  Sleep(500)
ENDREPEAT

Wait and synchronization

Various wait functions pause script execution until conditions change, with optional timeouts.

WaitForChange(GetServo(D0), 1000)
WaitFor($value1 = $value2, 1000)
WaitUntilTime(17, 30)   # blocks until 17:30 (24-hour)

Halt(), Pause() and Print()

Halt exits the current script. Pause stops execution until another script resumes the control or until the user stops it. Print sends output to the debug console.

Halt()
Pause()
Print("This is some text")
Print("Today is " + $Day)

Exec, LoadProject and CheckForUpdate

Execute external programs, load projects (replaces current project), and check for ARC updates.

Exec("C:\\Windows\\notepad.exe", "C:\\MyFile.txt")
LoadProject("MyTest.ezb")      # replaces the current project; subsequent commands are not executed
$x = CheckForUpdate()

Variable basics

Variables are global across ARC. Types are dynamic and determined by assignment.

$str = "This is a string"
$number = 6
$dec = 3.14
$byte = 0x52
$bool = true
$result = ($x > $y)
$number++    # increment
$number--    # decrement
$x = 123 << 1    # shift left
$x = 123 >> 1    # shift right

Arrays

Create and manipulate arrays.

DefineArray($myArray, 10)
DefineArray($myArray, 10, 2)   # default fill
AppendArray($myArray, 10)
FillArray($myArray, 88)
$x = GetArraySize("$myArray")
Sort($myArray, Ascending)

String and byte functions

Common string and byte utilities.

$len = Length("This string is 33 characters long")
$char = GetCharAt("Hello World", 2)        # zero-based index
$byte = GetByteAt("Hello World", 2)
$value = GetByte("H")
$value = GetAsByte("H")
$hex = ToHex(56)

Split and substring:

$contents = Split("One, Two, Three", ",", 1)
$value = SubString("Cat In The Hat", 4, 2)

Counting, searching and conversion

$apples = Count("apple apple apple", "apple")
$found = Contains("Cat In The Hat", "Cat")     # case-insensitive
$index = IndexOf("Cat In The Hat", "In")       # index of first occurrence
$numeric = IsNumeric($x)
$string = ToString($hexData)

Binary and bit helpers

$val = SetBits(1,0,0,0,0,0,0,0)
$str = ToBinaryString(254)
$bit = GetBit(255, 1)

Clear and manage variables

ClearVariables()
ClearVariable("$MyVariable")
DumpVariables()   # prints all variables and values

Math and scientific functions

Common math operations supported: Sin, Cos, Tan, ASin, ACos, ATan, Sinh, Cosh, Tanh, Abs, Sqrt, Ceil, Floor, Exp, Log10, Log, Max, Min, Round, Power, E, Pi, Now, Today.

$x = Sin(27)
$y = ASin(27)
$root = Sqrt(9)
$pow = Power(2, 4)
$rounded = Round(9.3848291, 1)

Mapping and random

Scale values between ranges and generate random numbers.

$mapped = Map(0.5, -1, 1, 0, 180)     # maps 0.5 from -1..1 into 0..180
$x = GetRandom(10, 50)
$y = GetRandomUnique(10, 50)

Min, Max

$lowest = Min(3, 5)
$highest = Max(3, 5)

DateTime functions

Functions available to manipulate and format dates and times.

MinDate(date1, date2)
MaxDate(date1, date2)
MonthName(monthNumber)
AddDays(date, days)
AddMonths(date, months)
AddYears(date, years)
AddHours(date, hours)
AddMinutes(date, minutes)
AddSeconds(date, seconds)
TotalHours(date)
TotalMinutes(date)
TotalSeconds(date)
FmtTimeSpan(value, format)
FmtNum(value, format)
FmtDate(value, format)

See the referenced MSDN links in the full documentation for formatting options.

Casting functions

CDBL()     # To Double
CInt()     # To Integer
CLong()    # To Long
CUint()    # To Unsigned Integer
CULong()   # To Unsigned Long
CDateTime()

Reserved variables

These read-only variables are provided by the environment:

$direction  $date  $month  $year  $day  $dayName
$hour  $minute  $second  $monthName  $time  $pi

Multiple EZ-B Boards

ARC supports multiple EZ-B boards. Prefix ports with the board index to address a specific board (for example: Servo(2.d0, 8) moves D0 on EZ-B board #2). If no board index is specified, board 0 is assumed. When multiple boards are used, board 0 handles Movement Panels.

ADC Ports

Analog inputs labeled A0–A7 on the EZ-B read 0–5V:

ADC0, ADC1, ADC2, ADC3, ADC4, ADC5, ADC6, ADC7

Virtual Servo Ports

Virtual servos are logical ports used by controls and movement panels — they do not control physical hardware directly.

V0 .. V19

Servo / Digital Ports

Ports that can control servos, PWM, digital outputs, and provide digital input readings:

D0 .. D23

UART Ports (EZ-B v4)

Three UARTs are available. Use UARTInit(), UARTRead(), UARTWrite() and UARTAvailable() to interact. Each UART has a 5,000-byte receive buffer.

UART0 TX: Expansion Connector
UART0 RX: Expansion Connector
UART1 TX: D5
UART1 RX: D6
UART2 TX: D18
UART2 RX: D19

Digital Port Serial Baud Rates

When using SendSerial() on digital ports, these are standard supported baud rates:

300, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200