Arduino 32u4 (MEGA) with built in GSM for $18

[alowhum]

Another very nice llittle board by Elecrow:

https://www.aliexpress.com/item/Elecrow-ATMEGA-32u4-A9G-GPRS-GSM-GPS-Board-Quad-band-3-Interfaces-GPRS-Class-10-DIY/32852490453.html

And here is a version with 4 built in relays:
http://www.aliexpress.com/item/Elecrow-Leonardo-GPRS-GSM-IOT-Board-with-SIM800C-Relay-Switches-Wireless-Projects-DIY-Kit-Integrated-Board/32829726566.html

Would it be possible to connect an NRF24 to the left-over pins I wonder.

Here's the wiki page for the board with relays:
https://www.elecrow.com/wiki/index.php?title=Leonardo_GPRS/GSM_IOT_Board_v1.0

[alowhum]

I bought the board with the relays as a basis for a smart lock.

I can't get it to work though, as I'm getting a TSP:FAIL, so a transport fail error.

First I connected directly to the 3.3v output of the board. No dice.

Now I'm using a 3.3v regulator board (powerled is on) and an eByte red NRF24L01 module, which are great. But still the same error.

That leaves a problem with the data connection.

• Pins 13 through 10 are available normally.
• I had to route the CE pin to pin 7
• I have not connected the IRQ pin.

I thought I'd check:

• Should I connect the IRQ pin to something? I don't think I have a real IRQ pin on the board available.
• Is there something about Arduino Leonardo that is different?

Ah, as far as I can tell the Leonardo is.. different.

I can try and connect via the ICS pins? Unfortunately they are of a smaller size on this board.

And I may need to use an extra RF24 library?

[alowhum]

By connecting the ICSP pins following this reference I got further!

2010 !TSM:FPAR:NO REPLY
2010 TSM:FPAR
2011 TSF:MSG:SEND,255-255-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
4013 !TSM:FPAR:NO REPLY
4013 TSM:FPAR
4014 TSF:MSG:SEND,255-255-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
6016 !TSM:FPAR:NO REPLY
6016 TSM:FPAR
6017 TSF:MSG:SEND,255-255-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
8019 !TSM:FPAR:FAIL
8019 TSM:FAIL:CNT=1
8019 TSM:FAIL:DIS
8019 TSF:TDI:TSL
10001 MCO:BGN:STP

I now have this in my code:

#define MY_RF24_CE_PIN 7
#define MY_RF24_CS_PIN 6

And connected the MOSI, MISO and SCK pins of the NRF24 module to the MOSI, MISO and SCK pins of the ICSP header.

[alowhum]

It seems to connect!

Here's some quick test code. It doesn't toggle the switches yet, it's just a connection test.

This is how I've connected the pins:

NRF24 adapter board -> Electrow GSM relay board
---------- -> --------
5V -> 5V
GND -> GND
CE -> Pin 7
CSN -> Pin 6
SCK -> middle pin on the inside of the board
MO -> Middle pin on the outside of the board (right behind the RST button)
MI -> On the corner pin closest to the middle of the board.
IRQ-> Not connected

/*
 * Author: Elecrow Keen
 * Date:6/30/2017
 * IDE V1.8.2 
 * Email:keen@elecrow.com    
 * Function: SMS control relay
 * Please note:
    When the the board receive "R1O" by SMS, the relay 1 will be open and the "R1C" that it will be close. 
    
    "R1O"/""R1C" means:
      R ->  Relay
      1 ->  Relay 1 
      O ->  Open
      C ->  Close
      
    It also used Relay2,Relay3 and Relay4.
 */

#define DEBUG true    //Open the debug information 

// Define Node ID
#define MY_NODE_ID 15
#define MY_PARENT_NODE_ID 0
#define MY_PARENT_NODE_IS_STATIC

//
// SETTINGS
//

// Enable and select the attached radio type
#define MY_RADIO_RF24                               // This is a common and simple radio used with MySensors. Downside is that it uses the same frequency space as WiFi.
//#define MY_RADIO_NRF5_ESB                         // This is a new type of device that is arduino and radio all in one. Currently not suitable for beginners yet.
//#define MY_RADIO_RFM69                            // This is an open source radio on the 433mhz frequency. Great range and built-in encryption, but more expensive and little more difficult to connect.
//#define MY_RADIO_RFM95                            // This is a LoRaWan radio, which can have a range of 10km.

// MySensors: Choose your desired radio power level. High power can cause issues on cheap Chinese NRF24 radio's.
//#define MY_RF24_PA_LEVEL RF24_PA_MIN
//#define MY_RF24_PA_LEVEL RF24_PA_LOW
#define MY_RF24_PA_LEVEL RF24_PA_HIGH
//#define MY_RF24_PA_LEVEL RF24_PA_MAX

// Mysensors security
//#define MY_ENCRYPTION_SIMPLE_PASSWD "changeme"    // Be aware, the length of the password has an effect on memory use.
//#define MY_SIGNING_SOFT_RANDOMSEED_PIN A7         // Setting a pin to pickup random electromagnetic noise helps make encryption more secure.

// Mysensors advanced settings
#define MY_TRANSPORT_WAIT_READY_MS 10000            // Try connecting for 10 seconds. Otherwise just continue.
//#define MY_RF24_CHANNEL 100                       // In EU the default channel 76 overlaps with wifi, so you could try using channel 100. But you will have to set this up on every device, and also on the controller.
//#define MY_RF24_DATARATE RF24_1MBPS               // Slower datarate makes the network more stable?
//#define MY_NODE_ID 10                             // Giving a node a manual ID can in rare cases fix connection issues.
//#define MY_PARENT_NODE_ID 0                       // Fixating the ID of the gatewaynode can in rare cases fix connection issues.
//#define MY_PARENT_NODE_IS_STATIC                  // Used together with setting the parent node ID. Daking the controller ID static can in rare cases fix connection issues.
#define MY_SPLASH_SCREEN_DISABLED                   // Saves a little memory.
//#define MY_DISABLE_RAM_ROUTING_TABLE_FEATURE      // Saves a little memory.

// Enable MySensors debug output to the serial monitor, so you can check if the radio is working ok.
#define MY_DEBUG 

// MySensors devices form a mesh network by passing along messages for each other. Do you want this node to also be a repeater?
//#define MY_REPEATER_FEATURE                         // Add or remove the two slashes at the beginning of this line to select if you want this sensor to act as a repeater for other sensors. If this node is on battery power, you probably shouldn't enable this.
//#define MY_RX_MESSAGE_BUFFER_FEATURE

#define MY_RF24_CE_PIN 7
#define MY_RF24_CS_PIN 6


// LIBRARIES (in the Arduino IDE go to Sketch -> Include Library -> Manage Libraries to add these if you don't have them installed yet.)
#include <MySensors.h>                              // MySensors library                  



 // the number of the Relay pin
const int Relay1 = 2;
const int Relay2 = 3;
const int Relay3 = 4;
const int Relay4 = 5;
/*
R1O means open  relay 1
R1C means close relay 1
The same as others 
*/
String R1O = "R1O";
String R1C = "R1C";
String R2O = "R2O";
String R2C = "R2C";
String R3O = "R3O";
String R3C = "R3C";
String R4O = "R4O";
String R4C = "R4C";

char target[] ="CMTI";  
int sms_no;
String get_message = "";   

void presentation()
{
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo(F("Elecrow SMS"), F("0.2"));
  
  // Register all sensors to gateway (they will be created as child devices): 
  present(1, S_BINARY);
}



void setup() {

      delay (2000);
      Serial.begin(19200); 
      Serial1.begin(19200);
      for(int i=2;i<6;i++){ // initialize the Relay pins status:
        pinMode(i,OUTPUT);
        digitalWrite(i,LOW);
      }
      //Power on the SIM800C
      
      pinMode(9,OUTPUT);
      digitalWrite(9,HIGH);
      delay(3000);
      digitalWrite(9,LOW);
      delay(1000);
      
      sendData("AT",2000,DEBUG);
      sendData("AT+CMGF=1",1000,DEBUG);        //Set the SMS in text mode
} 

void loop() { 
       if(Serial1.available()>0){
        Serial.write(Serial1.read());
            
          if(Serial1.find(target)){                  //If receive a new SMS
             sms_no = Serial1.parseInt();            //Get the SMS ID        
             get_message = "AT+CMGR="+(String)sms_no; //The command of the content of the SMS
             Serial.println("******************** Print the relay status *********************" );
             Data_handling(get_message,500,DEBUG);    //Get the content of the SMS 
             Serial.println("*****************************END*********************************" );
         } 
         
     }
     while(Serial1.read() >= 0){}                     // Clear serial buffer   
}

void Data_handling(String command, const int timeout, boolean debug)  //data handling function
{
    String response = "";    
    Serial1.println(command); 
    long int time = millis();
    while( (time+timeout) > millis()){
      while(Serial1.available()){       
        response += (char)Serial1.read(); 
      }  
    }    
   if (response.indexOf(R1O)>=0) {
    digitalWrite(Relay1,HIGH);
    if(debug){
    Serial.println("Open Relay 1");
    }
    }
   else if (response.indexOf(R1C)>=0) {
    digitalWrite(Relay1,LOW);
    if(debug){
    Serial.println("Close Relay 1");
    }
   }
   else if(response.indexOf(R2O)>=0) {
    digitalWrite(Relay2,HIGH);
    if(debug){
    Serial.println("Open Relay 2");
    }
   }
   else if(response.indexOf(R2C)>=0) {
    digitalWrite(Relay2,LOW);
    if(debug){
    Serial.println("Close Relay 2");
    }
   }
   else if (response.indexOf(R3O)>=0) {
    digitalWrite(Relay3,HIGH);
    if(debug){
    Serial.println("Open Relay 3");
    }
   }
   else if(response.indexOf(R3C)>=0) {
    digitalWrite(Relay3,LOW);
    if(debug){
    Serial.println("Close Relay 3");
    }
   }
   else if(response.indexOf(R4O)>=0) {
    digitalWrite(Relay4,HIGH);
    if(debug){
    Serial.println("Open Relay 4");
    }
   }
   else if(response.indexOf(R4C)>=0) {
    digitalWrite(Relay4,LOW);
    if(debug){
    Serial.println("Close Relay 4");
    }
   }else
   Serial.println("....Error message....");
}

void sendData(String command, const int timeout, boolean debug)  //Send command function
{
    String response = "";    
    Serial1.println(command); 
    long int time = millis();
    while( (time+timeout) > millis()){
      while(Serial1.available()){       
        response += (char)Serial1.read(); 
      }  
    }    
    if(debug){
      Serial.print(response);
    }    
}

[shabba]

How are you getting on with it? What spare pins are you using etc?
Have one sitting on my desk making me feel guilty for not hooking it up!

[alowhum]

All that is mentioned in my posts above?