Count car-starts

[flopp]

@mfalkvidd
But if I put ! inside ( it works

if (!resend((volumeMsg.set(starts)), 5))return;

[mfalkvidd]

Yes, sorry about that. I edited my previous post to have ! inside ().

[flopp]

This post is deleted!

[Zeph]

OK, let me see if I understand your overall flow.

You have your node connected to switched 12V power in the car. When you turn on the car, the uC gets power, when you turn off the car it loses power. When the car is cranking, the voltage drops enough that it tends to reset again (or else the cranking position on your key switch actually cuts off auxiliary power used by the uC).

So if you are at home and in range, loop() is called by the Arduino runtime just once; at the end of loop() the uC goes into an infinite busy loop rather than return, staying there until power is lost again. If you are away from home or the packets are lost for other reasons, resend() will cause a return from loop(), so that loop() will be called again by the Arduino runtime, so it will just keep trying until either power is lost, or it makes contact with your wireless network again.

Meanwhile every time it starts, the first byte of eeprom is incremented in setup(), and then loop() tries to fetch VAR1, and send VAR1+eeprom(0) back. If it succeeds, then the first byte of eeprom is zeroed.

Right?

That sounds reasonable. My immediate concern would be inconsistent operation during cranking, if the input voltage went just low enough to make the uC unstable. If your car's wiring cuts the power entirely, not a problem. Likewise there appears to be time for the uC to boot, and fully update eeprom, before losing power during cranking. (It's best not to be writing eeprom as voltage drops). It appears that those are not problems for your system tho.

[Zeph]

@flopp said:

12v can be handle by the Arduino Pro min on RAW pin

Cars go well above 14V during operation (as well as having noise glitches on top of that). If the regulator is only good up to 12v, operation could be marginal. Hence the suggestion from @tbowmo of a couple of diodes in the power feed, to drop a bit of the voltage as seen by the regulator.

[flopp]

@Zeph
Fully correct :) thanks for summarizing.

Car A have a built in USB where I, today, take power. I have to test if the voltage will go low so the uC will not get correct power but not 0 volt(restart), I don't know what will happen then. This was your question?
Car B have cigarette plug(12v output) so I use a converter to 5V, I think these converters can handle low input and still have 5V on output.

I will test it for a while and count starts in my head(good luck)

Next idea is to have a buzzer to beep when it has successfully sent data to Controller, just as information and if it beeps when I am away from home I have a mistake in the sketch

[flopp]

@Zeph
you are right about 14V.

Best should be to hide uC and connect to power(which only have power after crank)

[mfalkvidd]

@Zeph said:

It's best not to be writing eeprom as voltage drops

This is correct. However, shouldn't the BOD take care of that problem? Might be a good idea to set the BOD to 4.3V i stead of the default 2.7 though?

[flopp]

@mfalkvidd said:

@Zeph said:

It's best not to be writing eeprom as voltage drops

What does that mean exactly? Write to eeprom when power disappear, how is that possible without power?

This is correct. However, shouldn't the BOD take care of that problem? Might be a good idea to set the BOD to 4.3V instead of the default 2.7 though?

Perfect, then it will die sooner I guess

[mfalkvidd]

@flopp said:

What does that mean exactly? Write to eeprom when power disappear, how is that possible without power?

Writing is not instantaneous. It might only take a millisecond, but during that time things can happen. So when the write starts, there is enough power. But half-way through the write power is lost. That leaves the eeprom in an unknown state.

[flopp]

@mfalkvidd
Ok, I read it "to write as counting voltage drop" but it was "write to eeprom during voltage drop".
It is now clear, thanks

[tbowmo]

@flopp

A more exotic "hack" could be to tap into the OBD2 interface, and for example check engine RPM to see if motor is running, or not.

See this link..
http://mechanics.stackexchange.com/questions/24171/how-to-detect-engine-ignition-on-off-status-using-obd2

[flopp]

@tbowmo
Something like this?
This looks really nice, something I want to try later on
http://youtu.be/kmZ2PUMOKB8

[flopp]

My sketch seems to work, only problem is presentation in domoticz

I will add a buzzer to now when it has reported to gateway

[tbowmo]

@flopp

There is an howto here http://www.instructables.com/id/Hack-an-ELM327-Cable-to-make-an-Arduino-OBD2-Scann/ looks pretty simple to get going, and read out the RPM's..

[flopp]

@tbowmo
Nice, I will test in a few weeks

[flopp]

I have now solve the problem with storing data in Domoticz at correct day.

I have another node that send back the same value as it is right now, every 2 hours

[flopp]

Version 1.12, changes gw.wait when asking for VAR from 5 sec to 1 sec. also added support for Buzzer on D3

[flopp]

This post is deleted!

[flopp]

Keep-alive version. I noticed when this Node didn't get any response from Controller it send back 0, which means that this day will be very many starts

// Made by Daniel Nilsson
// Tested with Domoticz 3.4967
// Version 1.1
// 2016-05-10

//Keep-alive since Domoticz seems to not storing data if not data comes in for 3 hours(user setting)

#include <SPI.h>
#include <MySensor.h>

#define CHILD_ID 0                          // Id of the sensor child
#define NODE_ID 7                        // same ID as real Car Counter

int Controller;                             // Current start counts from Controller, like Domoticz

MySensor gw;
MyMessage volumeMsg(CHILD_ID,V_RAIN);
MyMessage lastCounterMsg(CHILD_ID,V_VAR1);

void setup()
{          
  delay(500);   // wait for radio
  
  //Begin
  gw.begin(incomingMessage, NODE_ID);
  // Register this device as Rain sensor (will not show in Domoticz until first value arrives)
  gw.present(CHILD_ID, S_RAIN);       
}

void loop()
{ 
  
    //Ask for starts from Controller.
  
      Serial.println("Request start counts");
      //gw.request(CHILD_ID, V_VAR1);
      while (Controller == 0) {
        gw.request(CHILD_ID, V_VAR1);
        Serial.println("No response from Controller");
        gw.wait(60000);
        }
      gw.wait(5000);
      
if (!resend((volumeMsg.set(Controller)), 5))return;
gw.wait(1000);
gw.sleep(120*60000); //less then timeout in Controller
}

// check if "st:fail" during gw.send, thanks n3ro
bool resend(MyMessage &msg, int repeats)
{
  int repeat = 1;
  boolean sendOK = false;
  int repeatdelay = 2000;

  while ((sendOK == false) and (repeat < repeats)) {
    if (gw.send(msg)) {
      sendOK = true;
    }
    else {
      sendOK = false;
      Serial.print("Error ");
      Serial.println(repeat);
    }
    repeat++; delay(repeatdelay);
  }
  if (sendOK == false && repeat == repeats){
    return false;
  }
  return true;
}

//Read if we have a incoming message.
void incomingMessage(const MyMessage &message) {
  if (message.type==V_VAR1) {
    Controller = message.getULong();
    //pcReceived = true;
    Serial.print("Received start counts from Controller: ");
    Serial.println(Controller);   
  }
}