At 2mA light sleep according to @emuboy’s doc (lower power modes definitely possible), that would be 0.01W per hour. An 18650 cell might have 12Wh on a good day. That would be over 50 days of standby.
I want to make a doorbell
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I think the discharge rate of a lithium cell it’s higher then the consumption of the esp
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I think that’s not quite the case but not crazy. Maybe 5% the first month then 1% thereafter?
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I have one 900mAh rechargeable AA battery at home that is not in use. As well as Imight get away with a long micro USB cable wired under the door.
If you are running a wire then you don’t really need it to be wireless?
I would get a cheap wireless doorbell and completely repackage it, I think that would be a fun project, but I understand if you want to learn microcontrollers or something else
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One of the tricks a pic can do is 0mA current consumption, and i mean 0mA not 10uA .
It’s a simple wake up on intrupt bit of coding .
Wake up on interrupt
Power transmitter
Spit out a bit of a fsk
Switch off transmitter
Go back to sleep
A coin cell will power that for years.
The power of a static architecture
Not such a stupid suggestion after all
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I’m not saying it’s a stupid suggestion.
PICs which at this point it’s a huge family, are not the only ones that can do that, it’s a commonly available feature nowadays…
Arduinos and eps cannot do that trick.Both draw current in sleep mode. Motorola released a static processor in the 70s for radio pagers. It’s certainly not a trick unique to pics.
And I’m sure there are some more modern offerings can also do it I just don’t know what they are
“Arduino” are not only atmega anymore
I know lots of things work from that coding environment. But the question is which ones are really good at low power
From this Thread
PIC12F508 can use a standby current of 100nA @ 2V, and typically 11uA with a configured oscillator frequency of 32kHz @2V, which is somewhat less than the typical 625uA at 4MHz @5V."
Apollo 3 Blue reaches 6 µA/MHz which is pretty incredible for a Cortex-M4F.
Silabs have wonderful low power MCUs as well, Atmel had the Xtreme Sleep series. I don’t remeber the exhact name.
Nordic has wonderful RF enabled chips with low power and are basically the insudtry standard for sensors and battery operated products.
Sorry, PICs are dead…
I believe the techmoan youtube channel once featured a battery-less wireless doorbell.
Which leads me to this steampunk suggestion:
A pull cord like an old flush cistern, spins up a geared dynamo which briefly powers an mcu long enough to emit an fsk (ask joe) via a directional antenna, also could include an actual bell for immediate feedback similar to the doorknocker™ solution by @Ryanf above.
Pros:
- battery-less
- Many hours spent making custom rf solution
- Unreliable mechanical troubleshooting fun
- highly ridiculous
- emf non-compliant
Cons:
- see above
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WiFi is not the appropriate technology if you’re wanting to run off a battery. Others have pointed at other technologies, zigbee and the NRF52 chipset being contenders in this type of situation.
You can buy very cheap and simple transmitters and receivers for 433 (and a few other bands) which are nothing more than modulators and demodulators, so you feed in the data you want to transmit and it modulates it onto the carrier and it’s emitted via the antenna, the opposite happens on the receiver end.
With a low power micro you could run for years waking up on button press.
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I absolutely agree with you the best solution is a microcontroller that can get down into the nA range and simple modulator switched off when the button is not pressed and the microcontroller just wake me up spit out the code.
The world is full of doorbell buttons with flat batteries getting years of service out of a primary cell should be the object of the exercise here in my opinion
÷?
I ended up buying a self charging one that somehow, when pressed, creates energy to send a signal to the speakers that are permanently plugged in the hallway. With the time on my hands and energy in my brain this year this was the best solution…
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it use a piezoelectric effect, you remember the old button powered cigarette ligher? the one you push instead of roll? it’s the same principle but instead of helping you dying earlier lighing a cigarette it wil generate a small radio signal that the receiver can pick up, neat.
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Lmao
Thanks for explanation!