Decoding systems with a decoding engine running on a mobile device configured to be coupled and decoupled to a card reader with wake-up electronics

A decoding system, comprising:

• a decoding engine running on a mobile device, the decoding engine in operation decoding signals produced from a read of a buyer's financial transaction card, the decoding engine in operation accepting and initializing incoming signals from the read of the buyer's financial transaction card until the signals reach a steady state, detecting the read of the buyer's financial transaction card once the incoming signals are in the steady state, identifying peaks in the incoming signals and digitizing the identified peaks in the incoming signals into bits;
• a transaction engine running on the mobile device and coupled to the decoding engine, the transaction engine in operation receiving as its input decoded buyer's financial transaction card information from the decoding engine and serving as an intermediary between a buyer and a merchant, so that the buyer does not have to share his/her financial transaction card information with the merchant;
• and
• one or more engines adapted to allow for an input of at least one of an input number, character and signatures to the mobile device.