OK thanks I will give it a try later, its gone 6am and I will get to bed and sleep on it !

OK   thanks  I think I understand better,   what changes awaiting_response back to true?
I presume I declare it as a boolean and true at the beginning?

[+SRDRSSI: 224OK]

Thanks for the ideas,  I think my lack of understanding of the buffer has hit the nail on the head.  

I did try declaring as a char and a byte, but having the check in the setup is not what I will be using on the project.

hen I run the  code below ,  I get      

+SRDRSSI: 224
OK

…and sometimes garbled charachters.    The first 2 returns are ok, the third is garbled then its random. even if I change the array to 32 or 255.

 So I think its the buffer thing.  Why I wonder is the buffer size set to 128 ?
I cant remember where I grabbed this code from.

I dont need to take more than one reading before clearing the buffers and going back to the data mode for sending housekeeping data.

But every second or so I want to send all data. ( and in a response to a command from the base unit as an acknowledge )

 if I get +SRDRSSI: 224 , in the char serInString array, ( consistantly ) I guess I can parse out the 3 bytes I need ( 2,2, & 4 in this case,)  for sending back to the base unit. ( converted to an int )

I want to display in the base unit, the signal strength of both receivers to warn about sending the robot out of range.

Code:

#include <NewSoftSerial.h>
#define RXPIN 14//  
#define TXPIN 15 //
#define SIMBAUD 9600
NewSoftSerial SIM(RXPIN, TXPIN);
int  serIn;             // var that will hold the bytes-in read from the serialBuffer
char serInString[128];  // array that will hold the different bytes  100=100characters;
// -> you must state how long the array will be else it won't work.
int  serInIndx  = 0;    // index of serInString[] in which to insert the next incoming byte
int  serOutIndx = 0;    // index of the outgoing serInString[] array;
const int AC2DPin = 17;  

void setup()
{
  Serial.begin(9600);
  SIM.begin(SIMBAUD);
  pinMode(AC2DPin, OUTPUT);
  digitalWrite(AC2DPin, HIGH);
}

void loop ()
{

  digitalWrite(AC2DPin, LOW); //LOW for sending AT commands, High for transparent data mode
  delay(120);
  SIM.println("AT+SRDRSSI?");  //  
  SIM.print("\n");
  digitalWrite(AC2DPin, HIGH);
  delay(10);
  readSerialString();
  //Serial.println ("------------ arduino is doing somenthing else ");  
  printSerialString();
  delay(1000);
}

void readSerialString () {
  int sb;  
  if(SIM.available()) {      
    while (SIM.available()){
      sb = SIM.read();            
      serInString[serInIndx] = sb;
      serInIndx++;

    }
  }  
}

void printSerialString() {
  if( serInIndx > 0) {
    //  Serial.print("Arduino memorized that you said: ");    

    for(serOutIndx=0; serOutIndx < serInIndx; serOutIndx++) {
      Serial.print( serInString[serOutIndx] );    //print out the byte at the specified index
      //serInString[serOutIndx] = "";            //optional: flush out the content
    }        
    //reset all the functions to be able to fill the string back with content
    serOutIndx = 0;
    serInIndx  = 0;
    Serial.println();
  }

}

…

Yes, when I slowed the data rate with the setupcode from my previous ( simplex ) project, it took the range from 7 to 150 meters.

I think the RFM22 will run at much slower baud rate, I think they run it with pulsed output like morse code for the really long range tests, but I have run out of time.

For testing I am just using the quarter wave vertical, without any form of groundplane for now.

The actual project will have dipoles at least, but at the moment, I am just comparing apples with apples.

The same quarter wave wires on the SIM20 modules ( in fact I noticed after the test that one was only 120mm long instead of 170mm ) at the same power give me 500m range, but as I said I dont trust my setup, and cant use the spreadsheet on my PC.

I will have another look at these modules one day when I have time, but this is a rush job now.

( I worked with diversity combiners in the 60s, and wondered what happened to them since,  the first time I noticed them on commercial equipment was on base stations for wireless mics 40 years later )

 I have just done a range check and ran out of road, with one unit on my bench ( with I have just noticed, only a 120mm antenna ! ) and me going walkabout.
The furthest I could get was 170m away from my desk, through 4 houses and 3 walls, and reception was still solid.

Tommorow I will fit correct length antennas and do the open space test .

I am using  SoftEasyTransfer.h  and NewSoftSerial.h for data transfer ( at 9600 baud at the moment )
Apart from the error checking and package structure security of Easy transfer, I also have a security code of my own before either end responds.

I am using the modules in transparent mode, and everything except the signal strength ( RSSI) monitoring is fine, but it looks like I have to switch back to AT+ commmands to get them.

I can switch to command mode in the loop, and get the RSSI level with the AT command, but it doesnt go back to receiving when a I go back to data mode?

I thought the range would be better, but I am sure its that I dont now how to set them up, and there doesnt seem to be anyone who has tried ?  They should have good performance with 18dbm Tx  and 118dbm Rx sensitivity .....  but I was doing something wrong.

I have given up on these RFM22 modules, and dug out the SIM20 modules, which I am trying to use. I have just done a range check and ran out of road, with one unit on my bench ( with I have just noticed, only a 120mm antenna ! ) and me going walkabout.
The furthest I could get was 170m away from my desk, through 4 houses and 3 walls, and it was still solid.

Tommorow I will fit correct antennas and do the open space test   As this post no longer refers to the title, I have started a new post at http://arduino.cc/forum/index.php/topic,155930.0.html

I am trying to set up an RF link using 2 SIM20 modules that I had in a drawer.

I can use them in the default transparent mode, but I want to set up a network ID etc, which is done by putting the devices into command mode, and writing to them with AT commands.

I remember before that I cant just send     SIM.println("AT+SRDDATAR=?");  for example ( I am using NewSoftSerial ) as it is ignored

I played around with \n and \r   and I can sort of get it working with the sketch below, but instead of returning the baud rate response, it returns either 33   or 161   or 67   in a random way each time I reset, (It should be a number from 0 to 7 ) followed by the   "sent message" every 2 secs.


If I omit the SIM.print("\r\n"); before the AT command line,  nothing is printed.

I have done a search on AT commands, and it looks like most times the serialPrintln is enough?

I dont want to send commands to change either unit if I cant get responses to keep an eye on whats happening, any ideas?

I have attached the AT commands manual for these units.

Code:

#include <NewSoftSerial.h>
#define RXPIN 14//   
#define TXPIN 15 //
int   AC2DPin = 17;
int  serIn; 
#define SIMBAUD 9600
NewSoftSerial SIM(RXPIN, TXPIN);

void setup()
{
  Serial.begin(9600);
  pinMode(AC2DPin, OUTPUT);
  SIM.begin(SIMBAUD);
  digitalWrite(AC2DPin, LOW); //command mode
  delay(120);
  SIM.print("\r\n");
  SIM.println("AT+SRDUART=?");
  if (SIM.available() > 0) {   // get incoming byte:   
    Serial.println(" something available ");
    serIn = SIM.read () ;
    Serial.println(serIn  );   
  }     
  digitalWrite(AC2DPin, HIGH); // data mode
}
void loop()
{
  SIM.print("hellohello");
  Serial.println(" sent message ");   
  delay ( 2000 );
}

"walking into an alley and roughed up by some thugs?"

Thats the one,  my kids gave me a disk with all the Larrys on, but I just dont have the time for games any more, and that was 25 years ago.

Plus there was no internet to get cheats from then, I remember we were stuck for weeks on the last stage of one Larry, nowdays you can get a hint in seconds.

Come to think of it, I think  all those games were stable, and never crashed.

It was the booby traps that made saving often a requirement :-)

I am only using the 4700mFd while I am checking it out on the Arduino board, as the onboard 3v3 supply cant handle the rush, but I scoped the cap and it hardly dips at all.     

"save early and save often."

I take it you never played Larry the Leisuresuit Lounge Lizard   or Space Quest then ?

You have not said where you are living ( it is handy if you put this on your profile )
Presumably it is Germany ?

Thanks, and thanks to Bob re the coax, I will bear that in mind,
What I tend to do latlely is to mount the transceiver on the antenna, and use ribbon cable to the 328 board,

Yes the  4700uF  is a  huge cap that can allow a current surge from the 3.3v  arduino line for the transmitter.