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  3. New library to read Arduino VCC supply level without resistors for battery powered sensor nodes that do not use a voltage regulator but connect directly to the batteries ;-)

New library to read Arduino VCC supply level without resistors for battery powered sensor nodes that do not use a voltage regulator but connect directly to the batteries ;-)

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supplyvcc
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  • ? Offline
    ? Offline
    A Former User
    wrote on last edited by
    #67

    Would this library also work on a WEMOS D1, which is powered by a esp8266?

    Paai

    YveauxY 1 Reply Last reply
    0
    • ? A Former User

      Would this library also work on a WEMOS D1, which is powered by a esp8266?

      Paai

      YveauxY Offline
      YveauxY Offline
      Yveaux
      Mod
      wrote on last edited by
      #68

      @Hans-Paijmans no, it's avr only

      http://yveaux.blogspot.nl

      1 Reply Last reply
      0
      • mfalkviddM Offline
        mfalkviddM Offline
        mfalkvidd
        Mod
        wrote on last edited by mfalkvidd
        #69

        On esp, ESP.getVcc() can be used. More info: https://www.letscontrolit.com/forum/viewtopic.php?t=130

        Edit: use MySensors' hwCPUVoltage() instead. See below for more information.

        1 Reply Last reply
        0
        • MiKaM Offline
          MiKaM Offline
          MiKa
          wrote on last edited by
          #70

          Hi,
          possible to read also internal VCC for SAMD21 and NRF5 platform core?
          MiKa

          YveauxY mfalkviddM 2 Replies Last reply
          0
          • MiKaM MiKa

            Hi,
            possible to read also internal VCC for SAMD21 and NRF5 platform core?
            MiKa

            YveauxY Offline
            YveauxY Offline
            Yveaux
            Mod
            wrote on last edited by
            #71

            @MiKa no, it's avr only

            http://yveaux.blogspot.nl

            1 Reply Last reply
            0
            • MiKaM MiKa

              Hi,
              possible to read also internal VCC for SAMD21 and NRF5 platform core?
              MiKa

              mfalkviddM Offline
              mfalkviddM Offline
              mfalkvidd
              Mod
              wrote on last edited by mfalkvidd
              #72

              @MiKa use hwCPUVoltage(), this works for AVR, SAMD and ESP8266. ESP8266 requires defining MY_SPECIAL_DEBUG though.

              MiKaM 1 Reply Last reply
              1
              • mfalkviddM mfalkvidd

                @MiKa use hwCPUVoltage(), this works for AVR, SAMD and ESP8266. ESP8266 requires defining MY_SPECIAL_DEBUG though.

                MiKaM Offline
                MiKaM Offline
                MiKa
                wrote on last edited by
                #73

                @mfalkvidd said in New library to read Arduino VCC supply level without resistors for battery powered sensor nodes that do not use a voltage regulator but connect directly to the batteries ;-):

                @MiKa use hwCPUVoltage() this works for AVR, SAMD and ESP8266. ESP8266 requires defining MY_SPECIAL_DEBUG though.

                Thanks ! It works on SAMD21E board :)

                MiKaM 1 Reply Last reply
                2
                • MiKaM MiKa

                  @mfalkvidd said in New library to read Arduino VCC supply level without resistors for battery powered sensor nodes that do not use a voltage regulator but connect directly to the batteries ;-):

                  @MiKa use hwCPUVoltage() this works for AVR, SAMD and ESP8266. ESP8266 requires defining MY_SPECIAL_DEBUG though.

                  Thanks ! It works on SAMD21E board :)

                  MiKaM Offline
                  MiKaM Offline
                  MiKa
                  wrote on last edited by
                  #74

                  It looks, its working also on NRF5 platform, tested with NRF51822 MCU ;) :+1:

                  https://raw.githubusercontent.com/d00616/arduino-nRF5-boards/master/51822_ITC_PolyU_HK/51822_ITC_PolyU_HK.jpg

                  1 Reply Last reply
                  2
                  • andredtsA Offline
                    andredtsA Offline
                    andredts
                    wrote on last edited by
                    #75

                    @Yveaux Hi, thanks for your work. Maybe I´m going over something that was covered before, but I need some help, I´m using this code in a door sensor with 2 aa battery, and reporting if battery changes, when the door opens or closes. My problem is that I always get diferent readings from close to open, so I´m always reporting battery level and using more power than needed. Thanks

                    YveauxY 1 Reply Last reply
                    0
                    • andredtsA andredts

                      @Yveaux Hi, thanks for your work. Maybe I´m going over something that was covered before, but I need some help, I´m using this code in a door sensor with 2 aa battery, and reporting if battery changes, when the door opens or closes. My problem is that I always get diferent readings from close to open, so I´m always reporting battery level and using more power than needed. Thanks

                      YveauxY Offline
                      YveauxY Offline
                      Yveaux
                      Mod
                      wrote on last edited by
                      #76

                      @andredts the voltage reference only has limited accuracy, therefore the reported battery voltage might vary slightly. Also the load on the battery can change, causing a variation in battery level reported. Not a lot you can do about that I'm afraid.
                      I experimented with sending all decreases in battery level wrt the previous value, and only large increases (eg 10% or more to detect change of batteries). Works quite well.

                      http://yveaux.blogspot.nl

                      andredtsA 1 Reply Last reply
                      2
                      • YveauxY Yveaux

                        @andredts the voltage reference only has limited accuracy, therefore the reported battery voltage might vary slightly. Also the load on the battery can change, causing a variation in battery level reported. Not a lot you can do about that I'm afraid.
                        I experimented with sending all decreases in battery level wrt the previous value, and only large increases (eg 10% or more to detect change of batteries). Works quite well.

                        andredtsA Offline
                        andredtsA Offline
                        andredts
                        wrote on last edited by
                        #77

                        @Yveaux Thanks, that was exactly the insight I was looking, for my door sensor with 2aa battery, your way worked great. For a scene controller with a CR2032 a had to not send also decreases greater then 10%, but hey, 10 steps is more enough.

                        YveauxY Nca78N 2 Replies Last reply
                        0
                        • andredtsA andredts

                          @Yveaux Thanks, that was exactly the insight I was looking, for my door sensor with 2aa battery, your way worked great. For a scene controller with a CR2032 a had to not send also decreases greater then 10%, but hey, 10 steps is more enough.

                          YveauxY Offline
                          YveauxY Offline
                          Yveaux
                          Mod
                          wrote on last edited by
                          #78

                          @andredts cr2032 is a totally different story. The voltage level fluctuates significantly when sending messages compared to AA powered sensors.
                          The 10% is only an example value and used for an increasing voltage level (that normally should only happen when replacing batteries). For a decreasing voltage (regular battery usage) you can just report the level and get much higher resolution. Question is if it will really be useful for cr2032 though...

                          http://yveaux.blogspot.nl

                          andredtsA 1 Reply Last reply
                          0
                          • sundberg84S Offline
                            sundberg84S Offline
                            sundberg84
                            Hardware Contributor
                            wrote on last edited by
                            #79

                            How about storing last 10 values and send an average every time?

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                            • andredtsA andredts

                              @Yveaux Thanks, that was exactly the insight I was looking, for my door sensor with 2aa battery, your way worked great. For a scene controller with a CR2032 a had to not send also decreases greater then 10%, but hey, 10 steps is more enough.

                              Nca78N Offline
                              Nca78N Offline
                              Nca78
                              Hardware Contributor
                              wrote on last edited by
                              #80

                              @andredts said in New library to read Arduino VCC supply level without resistors for battery powered sensor nodes that do not use a voltage regulator but connect directly to the batteries ;-):

                              @Yveaux Thanks, that was exactly the insight I was looking, for my door sensor with 2aa battery, your way worked great. For a scene controller with a CR2032 a had to not send also decreases greater then 10%, but hey, 10 steps is more enough.

                              For having consistent measurements with a CR2032 you should measure voltage as first action after waking up from sleep.
                              I keep the value in a variable and process it after "action" message of the node.

                              If possible, run at 1Mhz on internal oscillator so the power consumption of the atmega stays very low (around 1mA instead of 3 at 8MHz/3V).

                              andredtsA 1 Reply Last reply
                              0
                              • gohanG Offline
                                gohanG Offline
                                gohan
                                Mod
                                wrote on last edited by
                                #81

                                I'd like to share my little experience with the 3.2V LiFePO4 AA batteries ad they are a very good solution since a single battery can be used and be directly measured through VCC without requiring any voltage divider or booster

                                1 Reply Last reply
                                1
                                • YveauxY Yveaux

                                  @andredts cr2032 is a totally different story. The voltage level fluctuates significantly when sending messages compared to AA powered sensors.
                                  The 10% is only an example value and used for an increasing voltage level (that normally should only happen when replacing batteries). For a decreasing voltage (regular battery usage) you can just report the level and get much higher resolution. Question is if it will really be useful for cr2032 though...

                                  andredtsA Offline
                                  andredtsA Offline
                                  andredts
                                  wrote on last edited by
                                  #82

                                  @Yveaux I know about that fluctuation, but for my use in a scene controller I would be happy just to know the battery is low. I have it running with a multi-button, were I have click, duble-click and click and hold, I only check battery at one click, because of its fluctuation, but if you use it more than 4 times e a short period that fluctuation is noted, and that is why a added to the 10% increase a 10% decrease gap on battery sent information. Thanks

                                  1 Reply Last reply
                                  0
                                  • Nca78N Nca78

                                    @andredts said in New library to read Arduino VCC supply level without resistors for battery powered sensor nodes that do not use a voltage regulator but connect directly to the batteries ;-):

                                    @Yveaux Thanks, that was exactly the insight I was looking, for my door sensor with 2aa battery, your way worked great. For a scene controller with a CR2032 a had to not send also decreases greater then 10%, but hey, 10 steps is more enough.

                                    For having consistent measurements with a CR2032 you should measure voltage as first action after waking up from sleep.
                                    I keep the value in a variable and process it after "action" message of the node.

                                    If possible, run at 1Mhz on internal oscillator so the power consumption of the atmega stays very low (around 1mA instead of 3 at 8MHz/3V).

                                    andredtsA Offline
                                    andredtsA Offline
                                    andredts
                                    wrote on last edited by
                                    #83

                                    @Nca78 said in New library to read Arduino VCC supply level without resistors for battery powered sensor nodes that do not use a voltage regulator but connect directly to the batteries ;-):

                                    @andredts said in New library to read Arduino VCC supply level without resistors for battery powered sensor nodes that do not use a voltage regulator but connect directly to the batteries ;-):

                                    @Yveaux Thanks, that was exactly the insight I was looking, for my door sensor with 2aa battery, your way worked great. For a scene controller with a CR2032 a had to not send also decreases greater then 10%, but hey, 10 steps is more enough.

                                    For having consistent measurements with a CR2032 you should measure voltage as first action after waking up from sleep.
                                    I keep the value in a variable and process it after "action" message of the node.

                                    If possible, run at 1Mhz on internal oscillator so the power consumption of the atmega stays very low (around 1mA instead of 3 at 8MHz/3V).

                                    Hi, I do read the battery first thing after wake up, my problem was when a had various click too close together. It`s good now that I only send battery values that a 10% higher or lower than my last stored value. I will take a look on the 1Mhz bootloader. Thanks

                                    gohanG 1 Reply Last reply
                                    0
                                    • andredtsA andredts

                                      @Nca78 said in New library to read Arduino VCC supply level without resistors for battery powered sensor nodes that do not use a voltage regulator but connect directly to the batteries ;-):

                                      @andredts said in New library to read Arduino VCC supply level without resistors for battery powered sensor nodes that do not use a voltage regulator but connect directly to the batteries ;-):

                                      @Yveaux Thanks, that was exactly the insight I was looking, for my door sensor with 2aa battery, your way worked great. For a scene controller with a CR2032 a had to not send also decreases greater then 10%, but hey, 10 steps is more enough.

                                      For having consistent measurements with a CR2032 you should measure voltage as first action after waking up from sleep.
                                      I keep the value in a variable and process it after "action" message of the node.

                                      If possible, run at 1Mhz on internal oscillator so the power consumption of the atmega stays very low (around 1mA instead of 3 at 8MHz/3V).

                                      Hi, I do read the battery first thing after wake up, my problem was when a had various click too close together. It`s good now that I only send battery values that a 10% higher or lower than my last stored value. I will take a look on the 1Mhz bootloader. Thanks

                                      gohanG Offline
                                      gohanG Offline
                                      gohan
                                      Mod
                                      wrote on last edited by
                                      #84

                                      @andredts you could make an average of the last 3-4 reads before sending the battery value

                                      1 Reply Last reply
                                      0
                                      • gohanG Offline
                                        gohanG Offline
                                        gohan
                                        Mod
                                        wrote on last edited by
                                        #85

                                        is it normal that just swapping a pro mini I am getting a voltage reading difference of 0.12V from same node?

                                        mfalkviddM 1 Reply Last reply
                                        0
                                        • gohanG gohan

                                          is it normal that just swapping a pro mini I am getting a voltage reading difference of 0.12V from same node?

                                          mfalkviddM Offline
                                          mfalkviddM Offline
                                          mfalkvidd
                                          Mod
                                          wrote on last edited by
                                          #86

                                          @gohan the internal reference is specified to be 1.0 to 1.2 V (see "29.5 System and Reset Characteristics" in the datasheet)

                                          So the voltage will vary between different chips.

                                          1 Reply Last reply
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