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Bluefruit energyconsumption and speaker
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Bluefruit energyconsumption and speaker

by mirzam on Mon May 03, 2021 3:09 pm

Dear Adafruit,

First off I really love the Circuitplayground Bluefruit!

I want to use an external speaker for the CP Bluefruit. And you recommend an already powered speaker, so I wondered what is a powered speaker? I tried to couple a PAM8302 2.5W to the audio out, A+ to A0, A- and ground to ground, and power to Vout. And that didn't work well. I tried a Musicalangel JH-MD04E2 mini speaker through the audiojack, it didn't work out either. However I get a clear good quality sound through small headphones. So I assume I haven't broken anything. Maybe I could turn up the volume on the internal speaker?

Next question is energy consumption. I'm making a talking teddybear. And it won't be very fun if daddy has to charge Teddy every day. I figured you could turn off power to neopixels and sensors by
power_pin = digitalio.DigitalInOut(board.D35) and power_pin.value = False
Additionally I think time.sleep() would save some power. What else can I do to save power when inactive?

I tried the real time clock adafruit pcf8523 and it was plug and play almost on CP Bluefruit, thank you very much!

mirzam
 
Posts: 5
Joined: Wed Apr 08, 2015 1:49 pm

Re: Bluefruit energyconsumption and speaker

by blnkjns on Tue May 04, 2021 1:32 am

If you need to cut down energy use, you can leave Bluetooth off, dim the Neopixels (at 10 out of 255 brightness they are stil fun), code in C++ instead of Python.
You can also increase the capacity: Use a single 18650 cell at 3000mA instead of a LiPo.
Did you try the internal speaker?
If you connect an amp, you need to decouple it. A sound signal goes from -1.5 to 1.5V, your analog out from 0-3.3V. So there needs to be a capactor in the line. Try 100nF.

blnkjns
 
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Re: Bluefruit energyconsumption and speaker

by mirzam on Wed May 05, 2021 2:29 pm

Hi. So I figured out my problem with the sound level. I amplified my MP3's with Audacity and now I'm happy with the loudness of the internal speaker. Tip for any other Teddy Bear builders, use Googles Text-To-speech library an prerecord sentences for the Teddybear. Amplify it, and don't worry about clipping, since the sound quality is a bit shitty anyway.

How do I code the circuitplayground in C++? I'm actually a Java guy, so C++ is not very far fetched for me :)

I'll post an update of the Teddybear project in this thread when I'm done.

mirzam
 
Posts: 5
Joined: Wed Apr 08, 2015 1:49 pm

Re: Bluefruit energyconsumption and speaker

by blnkjns on Wed May 05, 2021 3:52 pm

You can also amplify without clipping. It's called compression.

blnkjns
 
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Joined: Fri Oct 02, 2020 3:33 am

Please be positive and constructive with your questions and comments.