Hello I'm making a small hobby project. I have an magnetic exercise bike, but it can show only one parameter at once and it doesn't have bluetooth, so I thought I will try to use arduino and make small android app that will store data and give me more insight about my ride.
I already bought bluetooth BLE module and made a circuit and test app and everything works, arduino reads low voltage caused by bike signal and BLE sends it to phone. But I want to calibrate my app to get more close results to these in bike mcu, or even, have bike mcu working next to my arduino module, so I wonder how could I connect those two so they both would get the signal and I wouldnt harm mcu with higher voltage?
mcu has two baterries 1,5V, so 3V. arduino needs more right? For now I'm using USB port from my PC but I thought about 4 x 1,5V.
right now I just intercepted cables from bike and integrated them to my arduino circuit. (i don't know the name of those cables but they're 2-pin female if that matters)
Impossible to answer without knowing which Arduino board that you have.
Ah yes, I forgot to add, I use UNO.
6V direct is too much for an Uno (it is 5.5V max). You can do a 4 AA pack and insert a silicon rectifier diode (1n400x) or 2 in series in the positive lead from the battery. Each diode will drop 0.6V to 0.7V.
Are you sure? I've read that recommended input voltage is 7-12v for UNO.
That is correct for the input to Vin. The battery pack with the diode connects to the 5V input. That is why it must be less than 5.5V. The 5V pin connects directly to the mega328 processor Vcc.
The Vin pin connects to the input of the onboard 5V regulator so it must be greater than 7V or the regulator will not regulate properly.
Thanks, I get it now, I didn't know you use those to input power, I used only Vin earlier.
Maybe I'll show what I have now, I should've do that at the beginning, it's something like this:
I use Vcc 5V to output 5V
On bike revolution I get LOW on input pin.
I just wonder how to connect bike MCU here.
What is the voltage at bike+ reference to ground? Where does the signal come from? Describe the signal.
What is the output voltage of the battery?
What is the voltage divider for?
