CODEWITHSUNDEEP
powershellserial-port
DarkLeafyGreen
DarkLeafyGreen

Reputation: 70406

Use powershell to write chars to serial port

Protocol

<STX>COMMAND<ETX><CHEKSUM>

a valid command is:

.004CT1000A.b

with STX = 0x02, ETX = 0x03, CHECKSUM = 0x0062, COMMAND = 004CT1000A

I want to send this command with powershell on a windows server to a serial port. However there are data type issues:

PS > [Char[]] $request = 0x02,0,0,4,"C","T",1,0,0,0,"A",0x03,0x0062
PS > $port.Write($request)

This logs a strange string with whitespace on the left and right of each character:

. . . . C T . . . . A . b

instead of

.004CT1000A.b

Any ideas what I am doing wrong?

and I tried

PS > [Char[]] $request = 0x02,"0","0","4","C","T","1","0","0","0","A",0x03,0x0062
PS > $port.Write($request)

which printed the right command but with a lot of whitespaces

. 0 0 4 C T 1 0 0 0 A . b

.004CT1000A.b is created with:

unsigned char checksum = 0x02;  
nrComm1->SendChar(0x02);
while(*TX_String)               
{
    nrComm1->SendChar(*TX_String);
    checksum ^= *TX_String++;       
}
nrComm1->SendChar(0x03);
checksum ^= 0x03;       
nrComm1->SendChar(checksum);

Upvotes: 1

Views: 3925

Answers (2)

jinghaoxu
jinghaoxu

Reputation: 1

This doesn't work for me. There are still lots of white spaces in between. [Byte[]] $request = 0x02,0,0,4,67,84,1,0,0,0,65,0x03,0x0062

My solution is: $request =[char]2 + "004CT1000A" + [char]3 + [char]62

Upvotes: 0

djs
djs

Reputation: 1690

You are using the .Net char object type, which is unicode. You probably want to convert your characters to ascii. Some info is here.

Or you could just use the decimal values for your ASCII characters and store it all in a byte array:

> [Byte[]] $request = 0x02,0,0,4,67,84,1,0,0,0,65,0x03,0x0062

Upvotes: 2

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