A steering mechanism having an interface for converting rotational motion to electrical signals, the interface comprising: a casing; a shaft which is rotationally moveable in a first direction and in a second direction; characterised in that the interface further comprises: a first and a second disc (16, 18) mounted on the shaft wherein each of the first and second discs (16, 18) is mounted to the shaft via a one-way clutch so that rotation of the shaft in one direction will cause movement of the first disc, the first disc being freely rotatable in the other direction, whereas rotation in the other direction will cause movement of the second disc, the second disc being freely rotatable in the first direction, and wherein each of the first and second discs (16, 18) includes an electrical conductor (20, 22); a first contact in electrical contact with the first electrical conductor and a second contact in electrical contact with the second electrical conductor; a contact bar which is mounted to the casing by means of suspension strut and springs (28, 30) so that it may pivot and rotate relative to the casing, the contact bar having two electrical contact areas (32, 34) arranged near respective ends of the contact bar at locations corresponding to the first and second discs (16, 18); wherein the first and second discs (16, 18) further comprise hooks (60, 62) which rotate together with the discs (16, 18), the hooks (60, 62) being arranged to engage with the contact areas (32, 34) of conducting bar when the first and second discs (16, 18) rotate, causing the respective contact area (32, 34) to come into contact with the corresponding conductor (20, 22); the contact areas (32, 34), the conductors (20, 22) and the contacts (46, 48) forming variable resistors, the resistance of which varies according to the point where electrical contact is made with the conductors (20, 22). a casing; a shaft which is rotationally moveable in a first direction and in a second direction; characterised in that the interface further comprises: a first and a second disc (16, 18) mounted on the shaft wherein each of the first and second discs (16, 18) is mounted to the shaft via a one-way clutch so that rotation of the shaft in one direction will cause movement of the first disc, the first disc being freely rotatable in the other direction, whereas rotation in the other direction will cause movement of the second disc, the second disc being freely rotatable in the first direction, and wherein each of the first and second discs (16, 18) includes an electrical conductor (20, 22); a first contact in electrical contact with the first electrical conductor and a second contact in electrical contact with the second electrical conductor; a contact bar which is mounted to the casing by means of suspension strut and springs (28, 30) so that it may pivot and rotate relative to the casing, the contact bar having two electrical contact areas (32, 34) arranged near respective ends of the contact bar at locations corresponding to the first and second discs (16, 18); wherein the first and second discs (16, 18) further comprise hooks (60, 62) which rotate together with the discs (16, 18), the hooks (60, 62) being arranged to engage with the contact areas (32, 34) of conducting bar when the first and second discs (16, 18) rotate, causing the respective contact area (32, 34) to come into contact with the corresponding conductor (20, 22); the contact areas (32, 34), the conductors (20, 22) and the contacts (46, 48) forming variable resistors, the resistance of which varies according to the point where electrical contact is made with the conductors (20, 22). a first and a second disc (16, 18) mounted on the shaft wherein each of the first and second discs (16, 18) is mounted to the shaft via a one-way clutch so that rotation of the shaft in one direction will cause movement of the first disc, the first disc being freely rotatable in the other direction, whereas rotation in the other direction will cause movement of the second disc, the second disc being freely rotatable in the first direction, and wherein each of the first and second discs (16, 18) includes an electrical conductor (20, 22); a first contact in electrical contact with the first electrical conductor and a second contact in electrical contact with the second electrical conductor; a contact bar which is mounted to the casing by means of suspension strut and springs (28, 30) so that it may pivot and rotate relative to the casing, the contact bar having two electrical contact areas (32, 34) arranged near respective ends of the contact bar at locations corresponding to the first and second discs (16, 18); wherein the first and second discs (16, 18) further comprise hooks (60, 62) which rotate together with the discs (16, 18), the hooks (60, 62) being arranged to engage with the contact areas (32, 34) of conducting bar when the first and second discs (16, 18) rotate, causing the respective contact area (32, 34) to come into contact with the corresponding conductor (20, 22); the contact areas (32, 34), the conductors (20, 22) and the contacts (46, 48) forming variable resistors, the resistance of which varies according to the point where electrical contact is made with the conductors (20, 22).