I have a few questions about a project idea I want to create. I will start with the problem, my initial idea and some requirements. I would be interested in hearing all input ideas, even different ideas for solving the problem and potential hardware choices I could make.
The Problem:
When I am in my cellar with headphones on and somebody rings the doorbell for the intercom system I do not hear the doorbell.
A Solution:
Have a transmitter send a signal to my room in the cellar and make a visual alert.
My Limitations:
I do not want to open or modify the current door intercom system as it’s not my property.
Instead, my plan is to put a small sound sensor next to the door chime (which is very loud) which can listen to the existing doorbell sound and then send a signal.
I would like the transmitter to ideally be low powered and able to run on a battery with at least a couple of months of battery life. The receiver will be in the cellar and can be an Arduino connected to power supply or even a Raspberry Pi. (I already have both)
Future Extension ideas:
In the future, it may be nice to have the receiver able to send an SMS or web push notification etc.
Thanks in advance.
(I attach a photo of the intercom, where I plan to install the transmitter.)
Get an ATTiny (the same family of chips used by arduinos and they are well euhm.. tiny) and try programming it with your arduino attiny programming with arduino
now set up the ATtiny with a battery pack (of course the bigger the battery the longer it will last) with the transmitter and the sound sensor. Set up the arduino in your basement with the LED strip and the receiver.
Then code the ATtiny to read the sensor and when it is above a certain value for a while (so that it doesnt go off on someone clapping hands or whatever) send a signal using the transmitter. The arduino spends its days listening to the 433 Mhz band and when there is a signal triggers the LED's .
Is that the sort of thing that would do it?
If so let us know how it goes and send pictures
Thats sounds pretty much like what I want to do. Thank you for the response.
A friend of mine used a Raspberry Pi which then listened for a specific sound. That Pi was just plugged in near the bell and communicated over wifi, but these needed constant power and no battery option.
Is there a way in which I can roughly calculate the power consumption of the 433 Mhz transmitter, ATtiny and sound sensor, just because I am interested to know how long would a 9V battery last.
Yeah a raspberry pi has a bit more power under the hood so can do a bit more with the data. The setup i described would all run at 5V. The power depends on the current drawn. The tiny would take about 1 mA, the transmitter only takes less then 1uA if not used (which it wont be most of the time), and a comparable sound sensor says it takes about 6 mA but it isn't clear from the data sheet if that is dependant on anything. Either way that would give us using Power = Voltage * Current : 5.0*0.007=0.035 W. Batteries are usually rated in mAh (mili Ampere Hours). A typical 9v has a capacity of like 400 mAh so that is 400/7 = 57 hours roughly. Hmm that seems a bit low. A smartphone battery is usually a better choice since it can do around 2000 mAh but that still isn't very long. The sure way is to built it and test it with a multi meter. You could do the calculation the same way i just did them.
Either way you could either make it rechargeable or run a cable from somewhere. The biggest power hog seems to be the audio sensor which makes sense cause it is an amplifier which is always on. Try to find a different audio sensor which has a low power consumption and do the calculation again. Or maybe if there is always a light on use a small solar panel?
DONT RUN THE CHIP OR COMPONENTS ON 9V, instead use a 5V battery or alter the voltage.
