Ping errating on Activity Board with USB and 6V connected simultaneously
banjo
Posts: 447
I have a Ping breadboarded on my Activity Bot to pin 8 through a 2 KOhm resistor and to 5V. A XBee WiFi, the wheel servos and a ping bracket servo are connected but not in use by the software.
As software I'm using the "Test Ping.c" that is included in the Learn library.
I get correct AND stable measurements in the terminal window when powering only through the USB cable.
With both the USB cable and the external power connected (5 * 1.2V rechargeable batteries), the measurements shown in the terminal window are incorrect and not stable. On longer distances they are only ~50 % of what they should be, and as said not stable
I've also tried with USB cable and 5 fresh alkaline batteries with same erroneous results.
Is this an expected behavior?
Shouldn't I connect both USB and external power at the same time?
As software I'm using the "Test Ping.c" that is included in the Learn library.
I get correct AND stable measurements in the terminal window when powering only through the USB cable.
With both the USB cable and the external power connected (5 * 1.2V rechargeable batteries), the measurements shown in the terminal window are incorrect and not stable. On longer distances they are only ~50 % of what they should be, and as said not stable
I've also tried with USB cable and 5 fresh alkaline batteries with same erroneous results.
Is this an expected behavior?
Shouldn't I connect both USB and external power at the same time?
Comments
My conclusion so far is that as soon as external power is connected, then the circuit is using that and not USB power. And with external power something is not working same as with USB power only.
Any clues or tips what to try?
Problems with the voltage regulator?
This is the data when connected through USB cable only:
...and this with USB and 6V external power supply:
BTW Every post I've done go through moderation which means it sometimes takes hours before they get visible. Not so easy to ask for or to provide help with the delays...
When it is in the socket I get the weird behavior but not after physically removing it. The XBee is functioning as I've used it together with my iPad.
Perhaps XBee is drawing power or otherwise interfering with the Ping sensor even if it is not used in the program?
Can anyone replicate or confirm this?
As a summary: by removing the XBee 56B WiFi physically from the XBee socket I don't have any problems, when putting it back I get erroneous Ping measurements with external power. The XBee is not in use in the simple Ping test program.
Is this a expected behavior, or is there something I can do to correct it?
The XBee itself seems to work correctly in another program.
Shortly, XBee WiFi is not supported with Activity Board rev A. It might or might not work, and in my case the XBee itself works, but the Ping doesn't behave correctly when the XBee and external power is connected.
On another rev. A I didn't have any problem though.
BTW your English is perfect. Are you an American living in Finland, Herra Vikstrom?
BTW
I happen to belong to the 5-6 % Swedish-speaking minority living in Finland so English is only my 3rd language, native language is Swedish and 2nd language Finnish (Herr Vikstrom in Swedish = Herra Vikstrom in Finnish = Mr Vikstrom in English). In addition I understand some German and Vietnamese.
In my daily work in a global company I'm speaking all three languages every day, but 99% of all writing is in English. So it is fairly easy to write English nowadays but sometimes I struggle with Swedish and Finnish instead... Same goes more or less with speaking.
BTW #2 Your English is quite good also :-)
Tack s