i2ctransfer expect binary or hex input in a specific format.

You're substituting strings that look like "0x30" and "0x12" but these are passed as plain strings, and likely malformed because:

• {regPartA} is just 4 chars like "0x30" (but possibly "30"?)

• {regPartB} might not be in the correct format either ("0x12")

If the format or spacing is off, i2ctransfer ignores or fails to parse it.

Here’s how to do it properly:

string regPartA = "0x30"; // or dynamically parsed
string regPartB = "0x12";

string commandArgs = $"-f -y -v 16 w2@0x18 {regPartA} {regPartB} r2";

response = SystemHelper.CommandExec("i2ctransfer", commandArgs);