MovieMaker
Well, I built a small robot so I could do experiments. I really miss having the notebook on the robot, but it was too small. So, I said to myself, I don't have speakers on the robot nor a microphone. So, I went out and bought an expensive Jam wireless speaker. I got it hooked up to the bluetooth and it sounded Great on my desktop. But, when I went to install it, it was way to big. So, I spent an equal amount of money on a Bump wireless speaker. It sounded not as great, but not to bad on my desktop when I hooked it up to the bluetooth. When I went to install it on the robot, I was lacking about an eighth of an inch, so I sorta made it an offer that it could not refuse. (I will have to glue it back, later.)
Bottom line, both speakers work fine when they are connected to the desktop. But I have tried several places to hook up to the robot and as soon as the EZB is powered up, the speakers sound like they have a wired connection with a cold solder joint. Static and noise takes over. When I run the program with ARC only (no EZB turned on), they work fine.
It is really lame having the robot in one room and having to listen to the voice come from the other room and having to use the microphone from the other room.
I have gotten myself in a mess.
Maybe you have an idea, I don't. I am expecting that you cannot overload the bluetooth on the EZ-B with too much bandwidth.
If you know an economical solution, please let me know. It is for the bob2 robot that I have just posted.
this sounds to me like noise. the Bluetooth coming with the ez-b may be interfering with the Bluetooth on the speaker.
How are the speakers wired ? Normally there is a plus and minus pair for each speaker as well as a shield. Is your shield grounded to the EZ-B ?
Mel, can I suggest something that you could try? Can you temporarily power the receiver from a totally isolated power source (while still on the robot), batteries would be ideal or maybe it came with a mains adapter, just watch out if the receiver unit is looking for a regulated supply (like 5V) etc. If after you have done this the problem disappears then this proves that you have a ground (loop) noise type problem. If this is the problem, then it is simple to solve with a isolated DC - DC converter, this way you will not need a second power supply to stop the ground noise as the isolation of the DC - DC converter will get rid of all the noise. To the receiver the DC - DC converter output is like a separate battery.
Hope this helps, let me know how it goes.
Tony
Thanks guys. These speakers are wireless bluetooth. I don't know if they make a wi-fi speaker, but, when I place them anywhere but around the robot, they work fine. One I turn on the Bluetooth on the robot, They start to lag and get noisy.
The robot is powered by it's own battery. And the speakers are powered by their own batteries. Both are not connected and there is no way to really connect them together because they are hard wired. The speakers act like a wireless headphone. When you turn them on, they turn off the speakers on the desktop and take over. All of that part works good. I think that it is a bluetooth bandwidth problem. And, I think it only has 9600 baud to communicate a lot of stuff.
That is my thoughts.
Glad you gave me a shoulder to cry on.
Mel, I have had great success with this audio sender.
www.ebay.co.uk/itm/2-4-GHz-wireless-digital-audio-transmitter-USB-VID-TRANS230KN-Konig-/400467876593?_trksid=p3284.m263&_trkparms=algo%3DSI%26its%3DI%26itu%3DUCI%252BUA%252BFICS%26otn%3D21%26pmod%3D400496308044%26ps%3D54
In the robot, I just install the receiver's PCB which first goes to a sound to light circuit (for the mouth LEDs) from there I wire the output to a stereo amp module
www.maplin.co.uk/3w-stereo-amplifier-module-37787
This setup works without any interference as you can see in the following video.
Where is the sound circuit? is it close to the bottom? I mean is it away from the main cpu?
Its on the same gear tray as the microcontroller, I try to keep everything together in one place.
This audio sender is not bluetooth (but still 2.4GHz), thats why it works well.
OK, that is the reason. It needs to be a Wi-fi wireless, not Bluetooth.