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    Best posts made by riataman

    • RE: Battery operated actuator

      Since some people people have found this useful I'm posting an update. Six months have passed and I'm very happy with the results. The nodes using the 4 second sleep are barely now into the nominal voltage of two AA batteries (3V) and I think those can last a copule of years like that.

      The 2 second sleep node is dipping a lot faster, but I suspect that the cause is the Si7021 taking readings every 3minutes that is accelerating the decline, even then I think this one could almost make it to a year.

      0_1461689309569_battery.png

      posted in Development
      riataman
      riataman
    • RE: Battery operated actuator

      In case anyone is interested in this topic I'm updating with my battery results after 1 month.

      Master is the sensor running the code I posted above, I hope I'm in good track for the battery to last at least 6months. JP and Magy are running the same code but sleep for 4 seconds instead of 2. I think they are following the same pattern as master but almost 2x slower. Ups in voltage seems to be 100% temperature related. Those are running in 2 AA batteries.

      Untitled.png

      posted in Development
      riataman
      riataman
    • RE: Battery operated actuator

      0_1454087697334_voltage.png

      There you go, I think the rate of discharge went down a little bit inline with the 2A alkaline discharge curves I have seen.

      You can't tell exactly by the chart, but all updates are up to today (Jan 29) Master is at 2.88V, JP is at 3.027V and Magy is at 2.979V.

      I think I'll call this a success since looks like I'm en route to last at least the 6months that was my original goal.

      By the way, I added a Si7021 sensor to the "master" node and it now reports temperature and humidity every 3minutes. It also has now a magnetic window sensor that it monitors via a pin interrupt to report open/closed state of a window.

      I'll try to find time to document all this project for the contest, here is an screenshoot of the web UI that I'm using to control the whole thing.

      0_1454088780552_accontrol.png

      The web UI is basically jquery mobile widgets plus a bit of javascript. The backend is written in python+flask running in a raspberry pi, that sends commands to my radio control, written in C also running in the same raspberry pi, the controller manages the radio communication, the nrf radio is directly wired to the raspberry pi IO pins.

      It controls 5 independent AC units, three are running on batteries and two are wall powered. The interface scales very well to desktop/mobile so I can control my ACs from anywhere on the internet.

      One of those nodes can also controls a Lutron IR wall switch. Another one has a natural gas sensor. And most of them have temperature/humidity sensors.

      posted in Development
      riataman
      riataman
    • RE: Battery operated actuator

      So I got around to implement this. My project is an air conditioner controller. I decoded my AC remote IR protocol and write code to send it using an arduino pro mini.

      This is the mainloop I'm using, basically I sleep 2seconds, then listen for commands for 15milli seconds.

      void loop()
      {  
        bool gotCommand = false;
        RadioCommand data;
      
        // Power up the radio, start listening and then sleep 15MS to allow
        // the radio to receive any commands.
        radio.powerUp();
        radio.startListening();
        LowPower.powerDown(SLEEP_15MS, ADC_OFF, BOD_OFF);
        // Clean the full pipeline. Only execute the last command
        while ( radio.available() )
        {   
          radio.read( &data, sizeof (RadioCommand));
          gotCommand = true;
        }
      
        if (nLoops > PING_LOOPS)
        {
          sendBatteryStatus();
          nLoops = 0;
        }
      
        radio.powerDown();
      
        // If we got a command and its actually different than last time
        if (gotCommand && lastSeq != data.seq)
        {
          SendWhirlpoolCommand (data.data);
          lastSeq = data.seq;
        }
      
        nLoops++;
      
        LowPower.powerDown(SLEEP_2S, ADC_OFF, BOD_OFF);
      }
      

      The sending side is a raspberry pi that just tries to send the same message for 5 seconds when it wants to send a command.

      I have very good reception so it always picks the package on the first try, this gives me an average command actuation of 1second, pretty good.

      I ran this in two AA rechargable nimh batteries for 3 days and the voltage didn't changed at all. Today I changed the batteries for two ElCheapo alkalines, the ones that I actually want to use. I'll report back how the batteries are progressing.

      I want to add a temperature/humidity sensor, probably going to be ordering either the Si7021 or the HTU21D as I need it go work with low voltages as I'm not using any step up, I'm running everything directly from the batteries.

      BTW, I'm not using any of the mysensors.org software as I wanted to write the whole stack myself for the learning experience (I have already the the nodes, controller and web interfaces for this) but I have found that this community has a lot of the same goals that I do.

      posted in Development
      riataman
      riataman
    • Battery operated actuator

      Has anyone had success with a wireless battery receiver?

      I think at this point battery transmiter are well unsderstood and can last years on batteries.

      But an arduino that can listen for commands is harder to pull of since the radio needs to be awake to receive commands, but that consumes lots of power.

      I searched for a ultra low (< 500uA) wireless receiver that could wake the arduino on receiving and but didnt find anything even close.

      The only other option i was thinking about is introduce an acceptable delay. Say you sleep for 8s (max watch dog timer lenght) and then listen for commands for 100ms or so. The transmitter would have to be either constantly transmiting for 8s when it wanted to issue a command or keep a synced clock with the reciver (it could be keep up to date in every transmission) depending on the acuracy of the clocks the receiver awake time could be minimized.

      Anyway iam going to test that last strategy after i finnish my proyect to operate on constant wall power and then ill try to switch it to batteries (its an AC remote control)

      posted in Development
      riataman
      riataman
    • RE: SI7021 Multisensor - first try

      @n3ro said:

      Big THX,

      now i have understand how to use the si7021 🙂

      Reading works great!

      But the sleeping current is very high ~1500uA

      If you got this breakout: http://www.aliexpress.com/item/Industrial-High-Precision-Si7021-Humidity-Sensor-with-I2C-Interface-for-Arduino/32340228487.html?ws_ab_test=searchweb201556_1_79_78_77_80,searchweb201644_5,searchweb201560_1 it includes a 3.3v regulator and level shifting so you can actually use the sensor with a 5v arduino but it consumes quite a bit of current (60uA in the ones I got) even when idling.

      What I did was desolder the regulator and solder a small wire to bypass it (sorry for potato quality pic).

      gy21.png

      Then I ordered this breakout for future nodes: http://www.aliexpress.com/item/New-HTU21D-Temperature-and-Humidity-Sensor-Module/1970355069.html?ws_ab_test=searchweb201556_1_79_78_77_80,searchweb201644_5,searchweb201560_1 that one doesn't seem to include any additional circuits (other than the pull up resistor and safety? resistor).

      posted in Development
      riataman
      riataman