Tagged Questions
18
votes
4answers
2k views
When a battery is your power source, what is ground?
For the sake of not incorrectly connecting my power supply and damaging my board I'm going to ask a relatively dumb question. Is ground on my board the negative terminal on my battery? Explicitly ...
5
votes
1answer
1k views
Arduino Duemilanove external power source with USB connected
Can Duemilanove USB interface be used for data transfer/programming when the board itself is connected to an external power source? (say, USB is not powerful enough)
What are the requirements for the ...
4
votes
1answer
71 views
How do I connect a signal shield to minimise noise from close proximity AC
In my proposed application, I will have approximately 30 RS-485 nodes configured in 3 chains spaced ~1m apart. There is a need to pass through 240v L-N-E, +5v, A, B, GND in each node. The physical ...
3
votes
2answers
629 views
arduino's pin number 7, isn't it dangerous without resistor?
I am reading a book called Getting started with Arduino. In that book, I don't understand why there is no resistor between pin number 7 and the switch (see diagram:)
If there is no resistor ...
1
vote
3answers
344 views
Common ground and voltages
Further to a question I asked earlier, I realised that common ground confuses me. I have a USB powered Arduino and a separate Battery supply. The battery supply negative is connected to the Arduino ...
1
vote
3answers
1k views
Sensor reading is chaotic when Arduino is powered by laptop unplugged
I have a Sharp proximity sensor connected to my Arduino (analog input). This Arduino is connected and powered through USB by a laptop.
When the laptop is plugged in, everything works fine (I get
...
1
vote
2answers
649 views
Controlling multiple motor drivers with one Arduino
I have one Arduino and I need to be able to control five to seven 12V motors that each draw about 4 amps.
Would I be able to use four Sabertooth 2X5 Regenerative Motor Drivers for this? Each driver ...
