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[sfrazer]

Sorry so tired I did not see that!  I just started installing the sensors.. 

So that may also solve my other issue too!  I have an interior garage light A4 with a motion sensor and an exterior garage light A5, no sensor yet.  Everything used to work great than we started noticing that when we left the house and the garage door hit the pavement the exterior light flicks on.   And when I come home the garage door goes all the way up then the exterior light flicks on.  So first I was thinking that the remotes were causing some interference, but that never happened before... 

Thanks a bunch,
Sandra

[Gilbert]

Interesting Tuicemen,  I always thought that a low battery caused the motion sensor settings to revert to unit code 1 of the programmed house code.  I only use HC B for all the motion sensors, so I have a low battery macro built (b1) to send me an email when the batteries need replacing.   At least I know that works.

How do you program a macro for low battery check ? I didn't find any flag or setting to check to validate that problem. If you can give me a clue (so I can try to build my own macro), it will be very appreciated.

BTW, is it some other setting(s) or flag(s) related to other sensors (DS10A by example) that can be programmed or checked ?


Gilbert

[TakeTheActive]

How do you program a macro for low battery check ?

Removing and re-installing the (good) batteries in most X10 battery-powered devices RESETS their HouseCode/UnitCode combo to the firmware default of A1. Thus, you can create a Macro to do "something" that will bring this to your attention (i.e. turn ON a certain lamp; speak a certain phrase; send an E-Mail, etc...)

[PrimeGuild]

Thanks guys, your advice worked. I didn't know that the Motion Sensors take up 2 codes. One for its active RF and the other for the Dawn/Dusk RF.

Thanks for helping me out here. No wonder my devices went crazy sometimes.

[Alan V]

Humm seems to be no set pattern to what these defaut too. Guess it's best to just change the batteries every time you do your smoke detector!Or at least once a year!

I thought of a simple mod that should prevent false transmissions when the battery runs low.  I ordered a couple of samples of the MAX6328UR26 uP Reset Circuit from http://maxim-ic.com.  Using the schematic for the MS14A at http://www.edcheung.com/automa/ms14a.htm as a reference, make the following connections:

MAX6328UR26       To            Signal
        Pin 1                            PIC12C508, Pin 8
        Pin 2                            End of R3 that is not connected to Pin 2 of the PIC12C508
        Pin 3                            PIC12C508, Pin 1

The PIC12C508 datasheet says that it can run reliably down to 2.5V when using the internal 4MHz oscillator.  The MAX6328UR26 has an open drain output.  This mod will disable the transmitter when the battery voltage is lower than 2.6V.  The MAX6328UR26 consumes a maximum of 1uA, so battery life should not be affected.

I plan on implementing the mod as soon as the samples arrive.  The design for the MS16A may be basically the same.  I'll keep you posted with my results.

[Brian H]

Keep us in the loop with the reset chip. Sounds interesting.

[Alan V]

Humm seems to be no set pattern to what these defaut too. Guess it's best to just change the batteries every time you do your smoke detector!Or at least once a year!

I thought of a simple mod that should prevent false transmissions when the battery runs low.  I ordered a couple of samples of the MAX6328UR26 uP Reset Circuit from http://maxim-ic.com.  Using the schematic for the MS14A at http://www.edcheung.com/automa/ms14a.htm as a reference, make the following connections:

MAX6328UR26       To            Signal
        Pin 1                            PIC12C508, Pin 8
        Pin 2                            End of R3 that is not connected to Pin 2 of the PIC12C508
        Pin 3                            PIC12C508, Pin 1

The PIC12C508 datasheet says that it can run reliably down to 2.5V when using the internal 4MHz oscillator.  The MAX6328UR26 has an open drain output.  This mod will disable the transmitter when the battery voltage is lower than 2.6V.  The MAX6328UR26 consumes a maximum of 1uA, so battery life should not be affected.

I plan on implementing the mod as soon as the samples arrive.  The design for the MS16A may be basically the same.  I'll keep you posted with my results.

Here's an update:

I wired the MAX6328UR26 "dead bugged" (chip upside-down) to the solder side of the PCB of a MS14A as described above.  It all works as expected.  At 2.6V or below, the transmitter is disabled.  This will prevent the MS14A from sending out incorrect transmissions when the battery runs low.

Further inspection of the cause of the initial reported problem revealed that the PIC12C508 used in the MS13A and MS14A (and probably the MS16A that I don't have) does not have an internal brown-out-reset circuit as part of the microcontroller circuitry.  The MS1XA may reset to A1 on power-up, but that's because a power-on-reset is generated within the microcontroller when the batteries are replaced.  Per the PIC12C508 datasheet, correct operation is not guranteed at voltages below 2.5V when configured to use the internal 4MHz oscillator.

This mod will work on the MS13A and MS14A.  I think the design of the MS16A is basically the same, so it should work there too.  You can get samples of the MAX6328UR26 at the Maxim website, or purchase them through their site at $2.05 each.

[steven r]

...The PIC12C508 datasheet says that it can run reliably down to 2.5V when using the internal 4MHz oscillator....

This would be another reason not to use NiMH batteries as two cells would only produce 2.4V.

[...I wired the MAX6328UR26 "dead bugged" (chip upside-down) to the solder side of the PCB of a MS14A as described above.  It all works as expected.  At 2.6V or below, the transmitter is disabled.  This will prevent the MS14A from sending out incorrect transmissions when the battery runs low....

My single application isn't critical enough for me to need the mod at this time but I will keep it in mind.
Thanks and I've left you a "helpful".

[Alan V]

...The PIC12C508 datasheet says that it can run reliably down to 2.5V when using the internal 4MHz oscillator....

This would be another reason not to use NiMH batteries as two cells would only produce 2.4V.

Good point.

Another reason not to use rechargeable batteries is that the self-discharge rate of Ni-Cad and Ni-Mh batteries can be as high as 20% per month.  So they are not well suited for applications like these where the current draw is very low.

Thanks for the vote.