CTS RTS and arduino. Any advice on how to implement this?

Projects Networking, Protocols, and Devices
1

I'm trying to use the parallax USB stick data logger. I am having no trouble interfacing with it through my FTDI cable. The difficulty I am running into is the logger requires the use of the CTS / RTS lines. I tried tying CTS to RTS and also tried tying CTS to ground. This is not working. Any advice on how to properly implement CTS / RTS on arduino would be greatly appreciated. Here is the code I am using just for testing purposes, IE to make sure I am communicating right through a terminal before I try to use this in my current project:

byte inByte;

void setup(){
  Serial.begin(9600);
  Serial1.begin(9600);

}

void loop(){
  while (Serial.available() > 0){
    inByte = Serial.read();
    Serial1.write(inByte);
  }
  while (Serial1.available() > 0){
    inByte = Serial1.read();
    Serial.write(inByte);
  }
}
2

Perhaps you should try the SPI interface. It will almost certainly be faster.

3

Good option. However, the SPI interface with that device is very non compliant to the SPI standards. It uses CS high to enable transmission as well as a 13 bit data frame. If you want to walk me through how to bit bang that very non compliant SPI standard that would be awesome. That was what I tried first, but I had no luck.

See page 16 of this document for more info:

Also, I have successfully changed the logger's baud rate to 3,000,000 and also have changed the mega's baud rate to 3,000,000. But that is interfacing through a terminal in both cases. So I'm not worried about speed. I just need to get the CTS and RTS signals down. Thanks for your response!

4

I just figured it out. You connect the RTS pin (#2) on the Parallax data logger to +5V and the CTS pin (#6) to ground and then TX and RX like you normally would.