So, I put my mobile near ccs32 controller and servo, and when somebody call me or send sms to me, servo starts little moves! So, it strange, that mobile make servo do it. I switch off serial port, but servo continue moves too. So, I think you must note this in your release notes that mobile makes servo move, it can crash robot.
RF Feedabck is the cause.
I am sure if you put your moble next to a unsheilded speaker. It would make noise as well.
It might no crash your bot, but it a good chance to make it do something that is not wanted.
It is called RFI or EMI
RFI - Radio Frequency Interference
EMI - Electro Magnetic Interference
You can actually hold a cell phone next to many appliances in your home, like TV, Computer Monitors, etc, since most cell phones have poor shielding.
Not all phones have equal radiation coming out.
My Motorola V60 has twice the amount (3dB higher) radiation then my buddies Nokia (forgot the model), with relatively the same quality of reception (all four or five bars).
Higher frequency circuits tend to display more radiation. Shielding a high-frequency circuit is often a challenge we face at my work (RF amplifiers).
-Tom