Acquiring a biometric print by means of a smartcard

A control method performed by a system comprising a smartcard and a peripheral device cooperating together to enable a biometric print to be acquired, the smartcard and the peripheral device being separate from each other;

• the smartcard including a biometric print sensor and the peripheral device comprising, other than a possible internal power supply, passive components only, including a user interface;
• wherein the method comprises:
• acquiring a biometric print by means of the biometric print sensor;
• transmitting at least one control signal from the smartcard to the peripheral device, each control signal being defined by a respective single level of an electrical characteristic;
• and
• configuring the user interface into a predetermined state in response to each received control signal, so as to guide a user in acquiring a biometric print by means of the biometric print sensor.