Good afternoon everyone,
I have an Arduino Severino, who has a serial output, with atmel8.
I'ma freshman in Arduino and I wonder if the PC to send commands to the arduino I have to use a MAX232 and connect you entries RX and TX arduino or if I can send commands through the serial cable that connects directly to the serial input arduino.
If you must use the RX / TX arduino how do I program these inputs to receive data from the PC.
Initially I just wanted to make a program to control the turning on and off an LED, and then move to control a motor.
Just keep in mind, if you're using the PC serial port to talk to the arduino, it WILL kill the arduino. To elaborate:
The serial port on the pc (DB9 connector) uses the standard RS232 voltage levels which are +12v (0) and -12V (1) (Yeah, logic is inverted in reference to voltage levels by the RS232 standard). These voltages will kill the arduino is connected directly. In this case a MAX232 level shifter is required.
As Grumpy_mike noted, if you're just going to talk with the arduino via USB serial link, this link uses TTL levels (+5v and -5V which are NOT the voltage levels specified by the RS232 standard), this will work fine.
In a nutshell: Using serial cable between arduino and PC - need MAX232
Using USB serial link: connect direclty, you're sweet - this link is used to upload programs to the arduino.