Hello All,
Everything is working… The problem was that the Arduino DUE puts out SCL and SDA on pins 21 & 20, respectively.
Thank you.

Problem Solved! When compiling, you must select Processor: ATmega 328 (3.3v, 8Mhz). Then the Serial Monitor will be fine at 9600 baud with the 3.3v Pro Mini.

What can i use to create an interrupt to wake a sleeping Arduino?
This using your Plant_Moisture_Sensor sketch.

When using the GW library, is there a way to communicate from one node to another, without having to go thru a controller?

I have read some of the 1.5 API, but I cant really tell if this can be done.

What about the LowPower.h library. Does it put the Radio to sleep?

I forgot to mention I only use the gw libary to put the 3.3v Mini to sleep.

My goal is simply to Xmit the battery voltage and moisture sensor data from one Pro Mini (with RF24) to another Pro Mini (also with a RF24 radio), not using gw calls. My receiving Pro Mini will simply control a relay.

I'm trying to combine two example sketches:

• Plant_Moisture_Sensor_Low_Power
• Arduino RF24XmitExample

#include <SPI.h>
#include <MySensor.h>
#include "RF24.h"

However, I'm getting compile errors. There seems to be a conflict between the MySensor gw library calls and the RF24 library calls.

The first of many compile errors I get are:
C:\Users\Dieter\AppData\Local\Temp\build3316808d9e952884aa2dded546ad6403.tmp\libraries\RF24\RF24.cpp.o: In function `SPIClass::setBitOrder(unsigned char)':

C:\Users\Dieter\AppData\Local\Arduino15\packages\arduino\hardware\avr\1.6.11\libraries\SPI\src/SPI.h:293: multiple definition of `RF24::csn(bool)'

In the end, I get: Exit status 1
Error compiling for board Arduino Pro or Pro Mini.

Both examples individually compile OK.

Any thoughts?
Dieter

Wow, I could never come up this sketch! I get the gist of it, but it will take me some time to figure out exactly how it works. I'm still learning the code syntax.

I don't understand: MySensor gw; and your other gw library calls like:

MyMessage msg(CHILD_ID, etc..)
MyMessage voltage,etc... and
gw.present(CHILD_ID ...)
gw.send(msg.set...)

Are these explained somewhere?

I was not going to use this library, but rather just another Pro Mini to "receive" the data from the sensor, using the RF24.h library. I have that working.

Can I use the gw library just using another Pro Mini? Do you have the "receive" sketch?

Thanks,
Dieter

@mfalkvidd

How do you drop the frequency to 1Mhz? Change the crystal? Is there a software way to do that?

I have since removed the Pro Mini power LED and the current dropped to 102 micro amps (with the moisture sensor removed). With the moisture sensor board IN and its LED removed, the draw is 1.4 ma - not so good (regulator still in).

I found that I can read the analog voltage (A0) using only the moisture probe (and not the board). It varies from 1.11v (dry) to 1.66v (fully wet) - but then no interrupts. I will try a 12hr wake up timer (as mentioned)...

Thanks

@mfalkvidd

I hesitate to remove the regulator. I rendered one Pro Mini useless trying to cut the trace to the Power LED.

I will try removing the StepUP. But not sure what will happen to the Pro Mini when the voltage dropes below 3.3v...

I was hoping that the Pro Mini will continue to run when the voltage to it drops below 2 volts.

I will try all your suggestions.
Thanks much.

Hello,

The current draw from 2 AA batteries (in series) when running this configuration is 2ma when in sleep mode. In my view is way to high. At 2200 mah, I calculate only getting about 45 days of battery life (2200mah / 2ma / 24 hrs/day).

Are my calculations correct?

While sleeping, removing the radio does not change the load on the batteries (it remains at 2ma).

Removing the Power LED on the PRO Mini will only reduce the current draw to about 1ma, giving 90 days of battery life.

I have tried the gw.sleep mode and my own sleep mode and get the same results.

Not sure how people are getting current draws below 1ma...

Dieter

Thanks.

I do have another question on what happens when an interrupt occurs. In the below example sketch, what code gets executed when the interrupt occurs: Is it at the interrupt handler "wakeUP()", or is it after the "detachInterrupt(1); ??

Typically when the interrupt happens, the interrupt handler code gets executed, and then it goes back to whatever code it was running when the interrupt happened.

Since, in this case, the interrupt handler does nothing, will it then execute the line after the "detachInterrupt(1);" ?

#include "LowPower.h";
void wakeUp(){
}
void setup() {
pinMode(3, INPUT_PULLUP);

Serial.begin(115200);
delay(1000);
}

void loop() {
Serial.println("Sleep Mode Entered");
delay(500);
attachInterrupt(1, wakeUp, CHANGE);
LowPower.powerDown(SLEEP_FOREVER, ADC_OFF, BOD_OFF);
detachInterrupt(1);

Serial.println(F("woke up"));
delay(500);

}