binding.read reads only 32 bytes

[germancmartinez]

Summary of Problem

When I try to read a large number of bytes (514 in this case) the function ends and returns only 32 bytes.

Code

...
var bytesRead;
var InBuf = Buffer.allocUnsafe(600); 
var portOptions = { baudRate: 9600, dataBits: 8, parity: "even", stopBits: 1, autoOpen: true };  
const binding = new Binding(portOptions);
await binding.open("COM3",portOptions);
...
await binding.write(Buffer.from('1006','hex'));   //OK
bytesRead = await binding.read(InBuf,0,514);  //NOT OK-->I get only 32 bytes

I'm using a Serial Port Monitor where I can see:

Versions, Operating System and Hardware

• SerialPort v9.1.0
• Node.js v14.17.0
• Operating system and version: Windows Server 2012 R2
• Architecture: x64

[reconbot]

Hey, sorry the docs are a little light on the bindings. But it will return a minimum of 1 byte and a maximum of specified bytes. You have keep reading until you get the number of bytes you want, read only stays pending while there isn't any data to read. The tradeoff here was for performance, but the usability is a bit annoying I know.

[germancmartinez]

Hi Francis, thank you! Using a while is working ok.

[myfreax]

@germancmartinez How done fix this issue?

[germancmartinez]

var portOptions = { baudRate: 9600, dataBits: 8, parity: "even", stopBits: 1, autoOpen: true };   
const binding = new Binding(portOptions);

async function mySerialRead(buff, offset, bytes){
    var bytesRead=0;
    var aux;
    while(bytesRead<bytes) `{`
        aux = await binding.read(buff,offset+bytesRead,bytes-bytesRead);
        bytesRead += aux.bytesRead;
    }
    return bytesRead;
}

[myfreax]

var portOptions = { baudRate: 9600, dataBits: 8, parity: "even", stopBits: 1, autoOpen: true };   
const binding = new Binding(portOptions);

async function mySerialRead(buff, offset, bytes){
    var bytesRead=0;
    var aux;
    while(bytesRead<bytes) `{`
        aux = await binding.read(buff,offset+bytesRead,bytes-bytesRead);
        bytesRead += aux.bytesRead;
    }
    return bytesRead;
}

thank your work. I have solved the problem using parser-delimiter package