I'm working to make a simple pedometer with Arduino, and after managing to find an algorithm that correctly finds the steps, I added a bluetooth extension (the overly popular and cheap JY-MCU) to check the steps via bluetooth.
I am facing a strange issue, though: when the bluetooth device is powered and waiting for a connection (red led blinking) the analog read function that reads data from the accelerometer goes crazy (thus the pedometer finds a step each second or so). When the bluetooth is powered down or connected to a device such as a mobile phone this doesn't happen.
Did anyone have this problem before? What could be the issue? My setup is easy, you can see it on the image.
I had other sensors as well but since the problem stays even when there are only those two connected I posted the bare minimum setup. At first I thought I could use some kind of pull-ups to stabilise the signal, but I really have no idea on where to tie them and if they can really be helpful at all...
Any help is appreciated.