G+_Curtis Fuller Posted June 22, 2017 Share Posted June 22, 2017 Greetings all, I’m trying to build a custom baby monitor for my wife who is Deaf. It needs to detect loud noises and listen for a specific series of tones from a feeding pump that our daughter uses overnight. The pump has a warning beep which alternates two tones, at about 4.1 kHz and 2.1 kHz. The device will then send a radio signal to the other room to trigger a bed shaker to notify my wife if our daughter is crying or if the pump has an error. I know how to do almost all of this … the only thing I can’t figure out is how to get the device to identify if the feeding pump is beeping. I thought I could have the Arduino listen to the audio sample and if there is one of the two beeps to flag a variable to true. If both are true within a timer period, then it would trigger the event to send the radio signal. However, I’m finding that getting the device to determine if a sound is at a certain frequency is complicated. I am a newbe and I tried asking on Stack Exchange (https://arduino.stackexchange.com/questions/39652/listen-for-specific-frequency) but the responses are above my head. I was excited about the possibility of using a LM567CN tone decoder, which I received today, but now I have no idea how to use those. Anyone have any suggestions on how I can make this all work? Thanks in advance! Link to comment Share on other sites More sharing options...
G+_Ben Reese Posted June 23, 2017 Share Posted June 23, 2017 Does the feeding pump have a light that comes on the same time as the tone? If so, the light sensor Padre showed off may be easier to implement. Listening for specific frequencies sounds more like a Raspberry Pi project than Arduino to me, but I'm not sure I'd trust the Pi to something that could be life or death. Might be ok if the receiving end had a watchdog timer builtin that alerts if no message is received from the Pi. I'm sure this could be implemented on Arduino, I'm just not sure how. I'm interested to see what others recommend though. Link to comment Share on other sites More sharing options...
G+_Curtis Fuller Posted June 23, 2017 Author Share Posted June 23, 2017 No, the pump doesn't have a light has an LCD display that shows the type of error but no let light or anything. Today I was thinking about seeing if I could pull the speaker out of it and get a current from the speaker but I'm really nervous about breaking into a thousand dollar pump that I might break something. ? Link to comment Share on other sites More sharing options...
G+_Black Merc Posted June 23, 2017 Share Posted June 23, 2017 Curtis Fuller your original premise is solid... The tone decoders will work, however its strictly an analog part(detection) designed to signal if a tone was their. Old land line phones originally functioned (touch tone)with similar devices. I believe you on the right track. See if you can find an old ham(amature radio operator) club, they will more than likely have the knowledge and tools to get the tone decoders tuned to the frequencies you have. Hams utilize touch tones for advance repeater functions. Link to comment Share on other sites More sharing options...
G+_Ben Reese Posted June 25, 2017 Share Posted June 25, 2017 Curtis Fuller so I mentioned your project to my wife (pediatric RN) and she thought the alarm on the feeding pump should be loud enough to trigger a noise sensor. Would it work to trigger on volume level only? I've used this app before and it works pretty well. Never with a feeding pump though. https://play.google.com/store/apps/details?id=dk.mvainformatics.android.babymonitor Link to comment Share on other sites More sharing options...
Recommended Posts