im sorry because im new in this forum. im sorry, its not RX, its TX.the RX led on arduino blinking when i click the button on VB app but the TX led on arduino does not blinking. thats indicates no data is sent from arduino.am i right? should i used readline instead of read existing?
It really doesn't matter what you use to read data that isn't there. If the Arduino isn't transmitting, then it matters not how you try to read the data. It would be like looking for a black cat that isn;t there, at midnight, not using a candle, rather than not using a flashlight.
but when i used the serial monitor, i can get the data. hurm, thats weird. anyway, thanks for your help. maybe i should use the serial monitor if i want to display the sensor data. but, based on your experience, what should i do to encounter this problem? do you have any idea. at least i can say something during the presentation of my project.
Seems like you've figured out what to do to encounter the problem. What you need to do to avoid the problem, I do not know. I do not use VB.
In C#, serial data reception is handled on another thread, so multi-threading techniques are need to receive serial data and show it in the GUI. Perhaps the same is happening in VB.