Bluetooth range on a Pi

[taylorkh]

Having played and worked with microcomputers since about 1980 I finally decided to dabble with Bluetooth I have a project where I need to get some sound out of a Pi Zero and Bluetooth seemed to be the path of least resistance. For the moment I am using a 3B+ as the Zero is still on the Big Brown truck and should be here in the next hour or so.

I purchased a Bluetooth receiver from Walmart last evening. For $7 US - how could I go wrong? I connected it to a small set of unpowered speakers and got it mated to the 3B+ (running Ubuntu). Easy. Wow! I played Heart's Dreamboat Annie album just to celebrate.

The box with the receiver claimed a range of 30 feet (about 10 meters for Metric folks). In fact the effective range seemes to be little more than 3 feet. The receiver is somewhat directional and as I changed its orientation with respect to the Pi the signal would drop and come back.

I was just wondering what sort of range other folks were experiencing. Is it a Pi limitation or my cheap receiver (not that cheap it is $2 more than the Zero

TIA,

Ken

[tempest766]

good choice in music.

keep in mind that as a generality, rf bandwidth is dependent upon distance. audio data over bluetooth has much higher bandwidth requirements than say, a keyboard.

and yes, 20 feet audio seems very optimistic to me.

[taylorkh]

Thanks tempest766,

A good point about bandwidth. In this project I am building a new jukebox for my workshop. Originally I had an old laptop/netbook with my 450+ album music collection converted to mp3 files which I would play through some even older powered PC speakers. I recently replaced the laptop with a 3B+. I figured that the 3B+ was more powerful than I needed so I am going to try to replace it with a Zero.

I looked at Bluetooth speakers but they are either tiny rechargeable speakers charged by USB - not a good option or AC powered home theater setups which are overkill for my small shop. I can run the old powered speakers from the Bluetooth receiver which will only be a couple feet from the Zero so I think it will work fine.

Dreamboat Annie is still on of my favorite Heart albums. As I recall it was their first release even though Magazine had been recorded first. I think I have all of Heart's albums in my collection except for Red Velvet Car. I have listened to it but I prefer their older sound - Bad Animals and earlier.

Ken

[W. H. Heydt]

I looked at Bluetooth speakers but they are either tiny rechargeable speakers charged by USB...

If the power requirement is low enough, they can be powered by a Pi. If that doesn't work (for any of a variety of reasons), a PI PSU will provide more power and the speakers needn't be within USB cable range of the Pi.

[taylorkh]

Thanks W. H. Heydt,

The speaker I was looking at last evening was rated ad 10 watts per channel - 20 total. That would be nominally 4 amps at 5 volts. It did have an internal battery which the USB would over time charge. Still, I would rather the speakers be charged independently from the Pi.

And for the bad news... UPS just delivered my box of Pi stuff from Adafruit. I hooked up the Zero and booted it to Raspbian. To my dismay I find that it does not have Bluetooth. That is on the Zero W. However, I do have a Zero W in the box so I guess I will have to use that one for this project. Or find some other way to get audio out.

Ken

[tempest766]

I looked at Bluetooth speakers but they are either tiny rechargeable speakers charged by USB - not a good option or AC powered home theater setups which are overkill for my small shop. I can run the old powered speakers from the Bluetooth receiver which will only be a couple feet from the Zero so I think it will work fine.

may work well, but being unlicensed RF spectrum, you really don't know until you try it. People try to do too much in the wifi bands and then don't understand why it has limitations. The licensed RF bands don't have anywhere near the interference to contend with, and some are by design less susceptible to naturally occurring interference.

A few years back the term UWB (ultra-wideband) was all the rage. It was suppose to give us consumer grade wireless personal-area-networks for apps just as you are designing, but it never lived up to the hype. It only found its niche in remote sensing and radar applications.

[taylorkh]

Thanks again tempest766,

So far my testing from the 3B+ to the Bluetooth receiver speakers has been done in my office with a whole bunch of other electronic stuff running. I think as I will arrange the pieces and parts I will have the Zero W Velcro taped to the back of an old 15" flat panel display (where I have a 3B+ now and the receiver will be Velcro taped to the wall a foot or less away. The only interference I would expect in the shop is when I fire up my Miller TIG welder on AC with high frequency start for aluminum - and I don't do that too often.

Ken

[Pedro Lu]

Gracias por la info, a que distancias están las cornetas estoy intendo algo parecido con mi sistema.

[taylorkh]

Menos de un metro.

Ken

[Douglas11]

Great choice.just keep in mind bandwidth requirements for audio quality.and also some RF range for power capacity.mykfcexperience survey

[taylorkh]

Thanks Douglas11,

This all sounded nice in theory but the Pi Zero-W is proving somewhat troublesome as I described in this thread on the Troubleshooting forum https://www.raspberrypi.org/forums/view ... 8&t=233247

At the moment I am experimenting with the Zero-W and WiFI. I had a heck of a time getting it to connect to my hidden WiFi network - because I could not type the pass phrase correctly

Actually the problem is that I am not seeing straight at the moment as I am dealing with some idiot seller on evilbay who sent me two camouflage wrist watch straps instead of the two VGA cables which I ordered. I had the ebay return label printed and the wrong items packaged for return yesterday morning. "Don't return them" he says. This morning I received an email with HIS mailing label, as a FULL PAGE pdf which he wants me to use. I had to shrink it in gimp, print it, overpack my original package and apply the new label.

But the Zero-W is connected to my network now. I have noticed that the USB output on both Zeroes is a little bit flaky. When I plug a USB to Ethernet dongle into the mini hub which I have attached it tends to kill the mouse and keyboard.

Thanks again for your comment,

Ken

[Lorem]

Thanks for the info, at what distances are the bugles I am trying something similar with my system.