Low Power: How much current? [Solved]

[Sparkman]

@brolly759 That's a different issue altogether. It's related to measuring battery voltage...

Cheers
Al

[brolly759]

@Sparkman said:

@brolly759 That's a different issue altogether. It's related to measuring battery voltage...

Cheers
Al

tlund posted 2 months ago reply quote 0
@tbowmo

My NRF's are the same $1 nrf's listed in the mysensors store, so probably fake. But I have still measured them to draw ~900nA in powerDown.

But I think I have found the culprint now. It seems the extra 20uA is caused by Arduino 1.6.5 (it may be that my installation is faulty).

My test setup:

pro mini
nrf
a simple sketch that does gw.sleep(60s)
1st test: sketch compiled & uploaded via Arduino 1.0.5-r2: 6uA
2nd test: sketch compiled & uploaded via Arduino 1.6.5: 24uA

[Sparkman]

@brolly759 Sorry, I was confused as your link is to post 250 in that thread, which is my post related to measuring battery voltage. What you are referencing is post 191: http://forum.mysensors.org/topic/1345/sensebender-micro/191

Cheers
Al

[scalz]

@Neverdie : at the beginning, as you were suspicious about the fact I get it. You can see here (look at the dates) that I had problems with low power and Charles helped me.
It's in french sorry : https://community.hallard.me/topic/53/question-à-propos-du-bod/30
At the same time I opened a thread on arduino forum : http://forum.arduino.cc/index.php?topic=336789.0
Another older topic that I solved myself (which contains some part of codes I was testing) : http://forum.arduino.cc/index.php?topic=336329.0
I hope you trust me now. and that I cannot I give a cake which is not finished cooking. I am not hurry. And I prefer the whole thing well packed in a lib, with derivative class, because the less the Mysensors libs are hacked inside, more beautiful it is I think. And then it is easier for users too.

@brolly759 : thank you for writing you results as I have no time for this on my side. Very strange your problem with ide. When I got low power, I was using ide 1.6.0. Maybe I will try 1.6.5 this week end to see, for curiosity. And I know Charles is using 1.6.x too. Another question, is your sensor a binaryswitchsensor only?? In this case, your way makes sense. But if you want to add sensors, you won't be able to keep 1uA without mosfet I think. Maybe I am wrong and you will find a great idea...
I follow your work, no doubt :smile:

[NeverDie]

@scalz said:

@Neverdie : at the beginning, as you were suspicious about the fact I get it. You can see here (look at the dates) that I had problems with low power and Charles helped me.
It's in french sorry : https://community.hallard.me/topic/53/question-à-propos-du-bod/30
At the same time I opened a thread on arduino forum : http://forum.arduino.cc/index.php?topic=336789.0
Another older topic that I solved myself (which contains some part of codes I was testing) : http://forum.arduino.cc/index.php?topic=336329.0
I hope you trust me now. and that I cannot I give a cake which is not finished cooking. I am not hurry. And I prefer the whole thing well packed in a lib, with derivative class, because the less the Mysensors libs are hacked inside, more beautiful it is I think. And then it is easier for users too.

@brolly759 : thank you for writing you results as I have no time for this on my side. Very strange your problem with ide. When I got low power, I was using ide 1.6.0. Maybe I will try 1.6.5 this week end to see, for curiosity. And I know Charles is using 1.6.x too. Another question, is your sensor a binaryswitchsensor only?? In this case, your way makes sense. But if you want to add sensors, you won't be able to keep 1uA without mosfet I think. Maybe I am wrong and you will find a great idea...
I follow your work, no doubt :smile:

@Scalz Not sure what you're referring to. I've taken what you've said at face value and still do. For the moment, if you are willing and able, it would help Broly759 and me if you would replicate Brolly759's approach (as he detailed above) and see if you can figure out why the IDE version is affecting his measurements. Which measurements are "correct"? Is that something you can help us figure out?

It would be best if we could all use the latest version number when taking measurements, unless there is good reason not to. I'm currently running IDE Version 1.6.5., and to date I haven't had problems with it. I did have some compile-time problems with some of the earlier Version 1.6 releases prior to the 1.6.5 release, but I don't recall now exactly what those problems were.

[scalz]

ok, I hope I will have enough time this week end because this week I have lot of work too, and Mysensors is jut fun for me. and I am running after time. It doesn't take time to reply for me, more for testings.. but I promise I will try the writeup. And I am trying to create my startup in greentech (automotive, cogeneration.. field) field. So most of my time is dedicated to my project. But I like playing too with arduino, so fun!

One thing I am sure, is when I got 140nA, it was BinarySwitch sketch too, from 2xaaa, ide 1.6.0. Then I added a BS250, to cut off nrf. And I got 140nA again in sleepmode. No problem, for sleep/wake up radio. And of course, I made the same tricks as Brolly in code. But maybe I had luck because I powered it through mosfet. Then I made same thing, BS250, for sensors, and uses BH1750 sketch. I had trouble with i2c. Charles helped me and then I got 140nA again. No problem with radio, sensors... All of this directly from 2xaaa. Then I played with boosters...
I will try brolly's case too, to see if I get same thing.
@brolly759 : you are using an arduin pin to power your nrf, am I right? to be in the same config as yours...

[brolly759]

GOOD MORNING crazy tinkerer's. Okay here we go again, I am actually going to need someone to verify what I am looking at here, nA and uA are giving me different readings:

Running the "for(); loop" in sleep() function with NRF VCC UNPLUGGED
Sleep current: .8uA - .9uA OR 273nA

Running the "for(); loop" in sleep() function with NRF VCC UNPLUGGED
Sleep current: .6uA - .9uA OR 114nA

@scalz I was powering the NRF directly from VCC. I will play around with connecting it directly to a pinOut on Arduino

[brolly759]

OKAY so... more numbers to play with... This is Arduino turning on/off NRF using an output pin.

• Connect Pin4 to VCC on NRF

• Add SPI.end(); and for();loop to include Pin 4 to turn LOW in sleep function

Add this code in define area:

#define WIRELESS_POWER 4

Add this code in loop():

void loop() {
  digitalWrite(WIRELESS_POWER, HIGH);
  delay(5);  
  sensor_node.begin();

Sleep current oState: .5uA - .6uA
Sleep current cState: .8uA - .9uA

@scalz Yes all my testing is on "binaryswitchsensor" sketch. I use the "DallasTempSensor" sketch when I want to test sleep() with a timer. There are SO MANY things you can do with a simple reed switch sensor. Doors, locks, windows, mailbox, fridge, cabinets, drawers... pretty much anything that moves and goes back in a certain place can be used with the "binaryswitchsensor".

[NeverDie]

@brolly759 When taking your measurements, were you using the current version of the MySensors library (v1.5) or a different one? Are all your other libraries the most up-to-date versions?

You used a Nano Pro, which I don't have. When the red Mini Pro's from Amazon arrive sometime later today, I'll try them.

Unless someone knows of a reason for the different results relating to different IDE versions, I think I will approach this by calling the underlying libraries directly, rather than through MySensors's abstraction layer. That way, if I don't encounter the differences, we'll know that it's a MySensors issue. For example, perhaps something you're setting is being undone by MySensors part way through the process of powering down, or something like that.

[scalz]

@brolly759 : I am happy for you. I was thinking that you were trying to make a sensor node (not only for binaryswitch). I agree with you for binaryswitch.. I think how you do is right for this purpose. cool. just one thing is with time, your coin cell will not provide full 3v for radio power transmission but it's another story.

See you soon.

[brolly759]

@NeverDie Good catch, I just checked the version.h file. v1.4.1

#define LIBRARY_VERSION "1.4.1"

In the utilities folder in MySensors library, all the files like RF24.h, LowPower.h are provided by the MySensors library. So I am assuming they were up to date when the MySensors library was created.

@scalz Even though its not full 3.3v it should be fine. The power range for NRF is 1.9v - 3.6v

My next project is to figure out battery monitoring as low as possible. ;) I know there are 2 ways, internal 1.1v reference or voltage divider. Can I do a voltage divider on an output pin and shut the output pin off when not using it?

[NeverDie]

@scalz said:

@brolly759 : I am happy for you. I was thinking that you were trying to make a sensor node (not only for binaryswitch). I agree with you for binaryswitch.. I think how you do is right for this purpose. cool. just one thing is with time, your coin cell will not provide full 3v for radio power transmission but it's another story.

See you soon.

Actually, your point regarding the coincell not providing full power could be relevant to the measurements (not saying it is in brolly759's case, but I definitely have seen it myself happen with a coincell powered arduino using the NRF24L01+): in cases where the coincell is low, doing a transmission can (because of internal resistance and the much higher current) can cause NRF voltage to drop below threshold, thereby shutting off the radio (not just sleeping it), which would obviously throw off the current measurement. Definitely something to be aware of.

[brolly759]

This is so frustrating, you know that?

So I reseated my cables to make sure I am getting the best connection. Now my current is the last configuration is:

sleep current oState: ~105nA
sleep current cState: ~457nA

@NeverDie my 2 AA battery setup right now are @ 3.452v

[NeverDie]

I recommend you don't use a coincell while testing. Use a big enough battery so that you won't be getting flakey results.

[brolly759]

@NeverDie my 2 AA battery setup right now are @ 3.452v

[NeverDie]

@brolly759 said:

This is so frustrating, you know that?

So I reseated my cables to make sure I am getting the best connection. Now my current is the last configuration is:

sleep current oState: ~105nA
sleep current cState: ~457nA

@NeverDie my 2 AA battery setup right now are @ 3.452v

In a way this might be good news. Perhaps something similar was causing the difference in your earlier measurements and not the different IDE versions?

I've had similar happen to me. Epecially because of plugging/un-plugging arduino's to modify programming jostles the wires or otherwise loosens connections, and then suddenly your measurements change for no apparent reason. Sometimes it can takes a while to figure out that's what's happening.

The NRF24L01+ is well known to be very sensitive to loose connections--a lot more than other radios. If you can solder your connections, definitely do!

In fact, it's so sensitive that even just running your supply and ground lines to the NRF close to the data lines can cause serious problems as well! Keep them as far aspart as you can. It's an unusually touchy radio.

[brolly759]

I just upgraded to Arduino IDE 1.6.5:

Board: "Arduino Pro or Pro Mini"
Processor: "Atmega328 (3.3V, 8MHz)

Sleep current: 19uA.

Using previous IDE I was @ 100nA.

Here is the sketch I am using:

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

#define SKETCH_NAME "Binary Sensor"
#define SKETCH_MAJOR_VER "1"
#define SKETCH_MINOR_VER "0"

#define PRIMARY_CHILD_ID 3
#define SECONDARY_CHILD_ID 4

#define PRIMARY_BUTTON_PIN 2   // Arduino Digital I/O pin for button/reed switch
#define WIRELESS_POWER 4

MySensor sensor_node;

// Change to V_LIGHT if you use S_LIGHT in presentation below
MyMessage msg(PRIMARY_CHILD_ID, V_TRIPPED);

void setup()  
{  
  pinMode(WIRELESS_POWER, OUTPUT);
  digitalWrite(WIRELESS_POWER, HIGH);  
  sensor_node.begin(); 
  pinMode(PRIMARY_BUTTON_PIN, INPUT);
 
   // Send the sketch version information to the gateway and Controller
  sensor_node.sendSketchInfo(SKETCH_NAME, SKETCH_MAJOR_VER"."SKETCH_MINOR_VER);

  // Register binary input sensor to sensor_node (they will be created as child devices)
  // You can use S_DOOR, S_MOTION or S_LIGHT here depending on your usage. 
  // If S_LIGHT is used, remember to update variable type you send in. See "msg" above.
  sensor_node.present(PRIMARY_CHILD_ID, S_DOOR);  
}

void loop() 
{
  digitalWrite(WIRELESS_POWER, HIGH);
  delay(5);  
  sensor_node.begin();
    
  uint8_t value;
  static uint8_t sentValue=2;

  sensor_node.sleep(5);  
  value = digitalRead(PRIMARY_BUTTON_PIN);
  
  if (value != sentValue) {
     // Value has changed from last transmission, send the updated value
     sensor_node.send(msg.set(value==HIGH ? 1: 0));
     sentValue = value;
  }

  sensor_node.sleep(PRIMARY_BUTTON_PIN-2, CHANGE, 0);
} 

[scalz]

I hope I won't see this difference too when I will retry with 1.6.5 (I tried with 1.6.0, and it was with Mysensors 1.4). otherwise I will move to Atmel studio...

[NeverDie]

@scalz said:

I hope I won't see this difference too when I will retry with 1.6.5 (I tried with 1.6.0, and it was with Mysensors 1.4). otherwise I will move to Atmel studio...

@scalz Can you retry with both IDE 1.6.5 and MySensors v1.5 fairly soon? Of course, as you've explained, I realize you have other commitments.... It just would help a lot if we're all on the same page.

[brolly759]

I am using v1.6.5. I burned the bootloader for Pro Mini, still no change.
Sleep mode: 17.9uA

FYI, when upgrading from v1.4 to v1.5 of MySensors lib, DO NOT overwrite all the files, Delete the folder, add the new v1.5 I had a lot of errors just now

I switched to v1.5 with v1.6.5 and I am getting 2uA in oState now. Now I am trying to play with the new sleep settings. will give an update soon.