[OpenTRV-dev] water monitoring

Sat May 24 14:30:03 BST 2014

getting more calm over the pin assignments.. sort of

to do pulse counting on our board the pulse input has to be attached to FTDI 
RX pin... its the same on OEM boards but they have just put an connector on 
for it... So thats one down

then in their sketches they say LED is connected to pin 9, but on the board 
its connected to pin 15 or PB1 (OC1A/PCINT1)... that does not make sense to 
me... HEEEELP :-D

and then the pin assignments for RFM... i can see what jeelib expects from 
the diagram at solderpad http://solderpad.com/openenergymon/emontx/

but its not clear to me in what file they are defined... and in the end how 
to override that so it matches our board...

this is only for water monitoring but i plan to work on something that can 
also handle solar, so that we can do dynamic demand stuff.... but i have to 
start somewhere :-D

-----Oprindelig meddelelse----- 
From: Bo Herrmannsen
Sent: Saturday, May 24, 2014 2:50 PM
To: Closed list for developer discussions
Subject: Re: water monitoring

hmm... of course our OpenTRV board can be used without mods...

but then i looked at the sketch'es from OEM and the one i made and it came
to mind that the OEM ones rely on the RFM being connected to the right
pins... as they are not defined in the sketch i started to look in the
jeelib files and found this in RF69_avr.h

#else // ATmega168, ATmega328, etc.

// #define RFM_IRQ     2
#define SS_DDR      DDRB
#define SS_PORT     PORTB
#define SS_BIT      2     // for PORTB: 2 = d.10, 1 = d.9, 0 = d.8

#define SPI_SS      2     // PB0
#define SPI_MOSI    3     // PB1
#define SPI_MISO    4     // PB2
#define SPI_SCK     5     // PB3

static void spiConfigPins () {
    SS_PORT |= _BV(SS_BIT);
    SS_DDR |= _BV(SS_BIT);
    PORTB |= _BV(SPI_SS);

But the SCK line on OEM boards are not connected to PB3.... where do i find
where it expects the what pin on the RFM69CW are connected to pins on the
AVR... ??

-----Oprindelig meddelelse----- 
From: Bo Herrmannsen
Sent: Saturday, May 24, 2014 2:08 PM
To: Closed list for developer discussions
Subject: water monitoring

I tried to make a sketch that should count pulses...

pin numbers are not correct... i just want to see if my logic is correct...
my water meter gives 1 pulse for each liter

the line:  rf12_control(0xC040);
// set low-battery level to 2.2V i.s.o. 3.1V

is alo wrong, if not mistaken the RFM69 can go down to 1.8, but if its just
a warning threshold then i guess 2.2 is a reasonble number to warn in good

if powered from 5V it might never happen, but i have keept battery power in
mind, just in case peoples meter are not near a mains socket

also we need to figure how RFM69CW should be connected to AVR... can we just
copy of how OEM connected the RFM12 and use that?


#define RF_freq RF12_433MHZ                                             //
Frequency of RF12B module can be RF12_433MHZ, RF12_868MHZ or RF12_915MHZ.
You should use the one matching the module you have.
const int nodeID = 18;                                                  //
emonTx temperature RFM12B node ID - should be unique on network
const int networkGroup = 210;                                           //
emonTx RFM12B wireless network group - needs to be same as emonBase and

#define RF69_COMPAT 0 // set to 1 to use RFM69CW
#include <JeeLib.h>   // make sure V12 (latest) is used if using RFM69CW
#include <avr/sleep.h>
ISR(WDT_vect) { Sleepy::watchdogEvent(); }                              //
Attached JeeLib sleep function to Atmega328 watchdog -enables MCU to be put
into sleep mode inbetween readings to reduce power consumption

typedef struct {
          int flow;
        int pulse;
      int battery;
} Payload;
Payload emontx;

const int LEDpin = 9;
//LED connected to Pin 9. Used to flash when transmitting

// Pulse counting settings
long pulseCount = 0;                                                    //
Number of pulses.
unsigned long pulseTime,lastTime;                                       //
Used to measure flowrate.
double flow, elapsedl;                                                  //
flow and liter
int ppl = 1;                                                            //
pulses pr. liter.

long debouncing_time = 1000; //Debouncing Time in Milliseconds
volatile unsigned long last_micros;

void setup() {
  Serial.println("OpenTRV Pulse counting Example");
  Serial.print("Node: ");
  Serial.print(" Freq: ");
  if (RF_freq == RF12_433MHZ) Serial.print("433Mhz");
  if (RF_freq == RF12_868MHZ) Serial.print("868Mhz");
  if (RF_freq == RF12_915MHZ) Serial.print("915Mhz");
  Serial.print(" Network: ");

  rf12_initialize(nodeID, RF_freq, networkGroup);
// initialize RFM12B
  rf12_control(0xC040);                                                 //
set low-battery level to 2.2V i.s.o. 3.1V

  pinMode(LEDpin, OUTPUT);                                              //
Setup indicator LED
  digitalWrite(LEDpin, LOW);

attachInterrupt(1, debounceInterrupt, RISING);                          //
interrupt attached to pin3


void loop()

  emontx.pulse=pulseCount; pulseCount=0;
  // if ready to send + exit loop if it gets stuck as it seems too
  int i = 0; while (!rf12_canSend() && i<10) {rf12_recvDone(); i++;}
  rf12_sendStart(0, &emontx, sizeof emontx);
  // set the sync mode to 2 if the fuses are still the Arduino default
  // mode 3 (full powerdown) can only be used with 258 CK startup fuses
  digitalWrite(LEDpin, HIGH); delay(2); digitalWrite(LEDpin, LOW);      //
flash LED

long readVcc() {
  long result;
  ADMUX = _BV(REFS0) | _BV(MUX3) | _BV(MUX2) | _BV(MUX1);
  while (bit_is_set(ADCSRA,ADSC));
  result = ADCL;
  result |= ADCH<<8;
  result = 1126400L / result;
  return result;

void debounceInterrupt() {
  if((long)(micros() - last_micros) >= debouncing_time * 1000) {
    last_micros = micros();

void onPulse()
  lastTime = pulseTime;        //used to measure time between pulses.
  pulseTime = micros();
  emontx.flow = int((3600000000.0 / (pulseTime - lastTime))/ppl);
//Calculate flowrate in Liters pr. hour

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