Arduino Nano PI Main Discussion

[lc516]

It's exactly the same audio stage as the Surf-PI.
The audio tone increases in volume as the target gets closer to the coil.

Hi,Qiaozhi

I tried to lower R20 to 30ohm,will that get noice on the circuit?

[lc516]

lc516 and bernte, and all who had silent sound with traditional speakers on Surf.
I alredy post modification for audio stage.

https://www.geotech1.com/forums/showthread.php?26208-Surf-PI-efficient-and-simple-speaker-driver-for-low-impedance-speakers

It will drive 6 Ohm speaker like crazy.
Only 3 transistors.

Thanks! This solved my recent troubles.

[Vadim18]

lc516 and bernte, and all who had silent sound with traditional speakers on Surf.
I alredy post modification for audio stage.

https://www.geotech1.com/forums/showthread.php?26208-Surf-PI-efficient-and-simple-speaker-driver-for-low-impedance-speakers

It will drive 6 Ohm speaker like crazy.
Only 3 transistors.

[lc516]

...

[6666]

If anybody in Australia is interested I have two pcb's for sale, $7 posted, payment by paypal.

[lc516]

you can also take a simple 2-3w amplifier module
or as main speaker a piezo

if you change the audio frequency in the code you could get louder audio if you use a frequency close the the resonant frequency of the piezo

Changing the PWM frequency is troublesome in arduino IDE.
so,I just changed the PWM duty cycle to about 5% ("analogWrite(audioPin, 20);"),it look a little better now.

Thanks for your information.

and, I found that if process the audio through the mcu, may get better results.
The current audio processing seems to lose some sensitivity, or it's hard for me to made it well on PCB.

[bernte_one]

Yes,I think it's work good on headphones,but I want use speaker.
As bernte_one said,maybe I need to up the PWM voltage to 12V.

Thank your reply ,and bernte_one's

you can also take a simple 2-3w amplifier module
or as main speaker a piezo

if you change the audio frequency in the code you could get louder audio if you use a frequency close the the resonant frequency of the piezo

[lc516]

I am using 32 ohm headphones and the volume is very good.

Yes,I think it's work good on headphones,but I want use speaker.
As bernte_one said,maybe I need to up the PWM voltage to 12V.

Thank your reply ,and bernte_one's

[surfdetector]

I used a speaker with 32ohm,but it's sounds too low.

how should I improve it to make louder?

I am using 32 ohm headphones and the volume is very good.

[Qiaozhi]

Take a piezo, 3-12v or 5-24v rating
All normal speaker i have tested are too quiet

Not Sure if the Audio stage is working like planned

It's exactly the same audio stage as the Surf-PI.
The audio tone increases in volume as the target gets closer to the coil.

[bernte_one]

I used a speaker with 32ohm,but it's sounds too low.

how should I improve it to make louder?

Take a piezo, 3-12v or 5-24v rating
All normal speaker i have tested are too quiet

Not Sure if the Audio stage is working like planned

[lc516]

I used a speaker with 32ohm,but it's sounds too low.

how should I improve it to make louder?

[bernte_one]

Some samples:

[bernte_one]

Build mine ready, within one day.
Was very easy, all settings checked with oscope.
Big THX to George for Support
If anyone is interested in scope pictures i can upload them

https://youtu.be/Z2XFnPe3u58

[green]

Hi Green.
Sorry for the delay in posting health went down again.
I would like your excel program if you would, It will be another learning curve but that's what keeps me going.

Got my boards and will have parts complete soon.
Code is almost done I'm having a little trouble with the timing interrupts but almost ready to try in the IDE and see if it compiles.
I realize this is not the perfect platform to do GB but once the code is done the nanno can be applied to other designs.

Thanks again

Any questions, ask.