A byte is 8 bits which has a maximum value of 255 (256 possible variations of the bits)

a float, or an int, or a decimal, or a short, etc... all consist of many bytes.

so an int16 is 2 bytes

an int32 is 4 bytes

a long (int64) is 8 bytes

the bytes are assembled together using bitwise operators to recreate the original intended value.

I don’t know what’s compatible with a float between windows an Arduino, since floats are considerably platform dependent. An int16, however, is easy

you’ll need to send your in on the Arduino as two bytes

and receive it on the ezb or what ever the receiver is, as two bytes

Here's JavaScript code from ARC that demonstrates how to receive and convert 2 bytes from the hardware UART into an INT..

(i don't use ezscript anymore)

First, initialize your hardware UART...

// initialize the hardware uart #0 at 9600 on ezb #0
UART.initHardwareUart(0, 9600, 0);

Now, send your data from the Arduino...

void sendSomeData() {

  Serial.begin(9600);

  int value = 12345;

  // split the value into 2 bytes and send over the wire
  Serial.write(value & 0x00FF);
  Serial.write(value & 0xFF00 >> 8);
}

// Get the number of bytes available to read
var bytesAvail = UART.hardwareUartAvailable(uartIndex, ezbIndex);

if (bytesAvail >= 2) {
   
   // Get the data as an array from the UART buffer
   var dataArray = UART.hardwareUartRead(0, 2, 0);
   
   var value = dataArray[0] + (dataArray[1] << 8);
   
   print("Your value is " + value);
   
} else {

   print("Not enough bytes available to assemble an int16");
   
}

I wrote this to receive 2 byte data ( this example for voltage) from the roomba (and charging state...single byte)....  It kind of worked but strangely just for voltage it wigged out on any other 2 byte data request... maybe it will help you out a bit...

uartinit(0, 0, 115200)
sleep(500)
$rx = UartAvailable(0, 0)

if ($rx=4)
    $RX_DATA = UARTRead(0, 0, $rx)
    $MSB=GetByteAt($RX_DATA,0)
    $LSB=GetByteAt($RX_DATA,1)
    $Charge=GetByteAt($RX_DATA,2)
    $Charge_source=GetByteAt($RX_DATA,3)
    $voltage=Round(($LSB+(256*$MSB))/1000,2)

  
 if ($Charge_source = 0)
      print("Not Docked")
    ELSE
      print("Docked")
    endif

    if ($charge=0)
      $dock_flag=0
      print("Not charging")
    ELSEif ($Charge=1)
      $dock_flag=1
      print("Recondioning charging")
    ELSEif ($Charge=2)
      $dock_flag=1
      print("Fast charging")
    ELSEif ($Charge=3)
      $dock_flag=1
      print("Trickle charging")
    ELSEif ($Charge=4)
      # $dock_flag=0
      print("Waiting to charge")
    ELSEif ($Charge=5)
      print("Error not charging/Fault")
      halt()
    endif  
   

    print("Battery Voltage = "+$voltage)
endif

Richard, the reason it would wig out is because the uartread() returns a string. In ezscript, you’d have to use uartreadbinary().

but, JavaScript is more powerful and faster

oh, the new roomba plugin I just finished reads sensor data. And has variable turning and such. It’s real great. I’ll publish it this week with the new arc.

@DJ.... Fair enough. I need to revisit that. FYI I am in the process of learning JavaScript for ARC as I can see the benefits over ezscript.... A quick JavaScript (with the plugin) for the roomba sensors would be most welcome... I like learning from example code....

Cheers

Thanks DJ and Richard.....love the quick replies here.

Time to buy JavaScript for Dummies then?

Assuming I do switch to JavaScript....Is there a similar ControlCommand function in JavaScript to control the other plugins?

Hmmm....

So with that code.... (DJ's code)...sending the number 1021....the code gives me the value 65021 at the end.

scratches head confused

Oh, I might have confused the byte order. Either on the sender or receiver, change the order of the bytes

so like, on the sender. Change the order to be...

Serial.write(value & 0xFF00 >> 8); Serial.write(value & 0x00FF);