A system for orienting slats of a sunshade system for protecting a façade , comprising : - a series of parallel slats each pivoting in both directions about a pivot axis (AVP); - and a device for pivotally driving slats that comprises : -- a drive carriage that is movable in translation in both directions along a longitudinal direction (L) orthogonal to the pivot axes (AVP) of the slats and over a determined path between a first end position to which it is elastically returned and a second end position; -- a mechanism for converting the longitudinal movements of the drive carriage into simultaneous pivotal movements of the slats ; -- a controlled actuator of the movements of the drive carriage which comprises a variable-length member made of a shape-memory material, the length whereof varies as a function of its temperature, a first end whereof is connected to a fixed anchoring point , and the other end whereof is connected to the drive carriage ; -- means for controlling the variation in the temperature of the variable-length member of the actuator in order to cause movements of the drive carriage between its two end positions; characterized in that the system comprises a controlled block for adjusting the angular orientation of the slats which is movably mounted between : - a retracted position; - and an active blocking position wherein, against an elastic biasing force applied to the drive carriage , the controlled adjustment block immobilizes, directly or indirectly, the drive carriage in an intermediate longitudinal position between its two end positions. - a series of parallel slats each pivoting in both directions about a pivot axis (AVP); - and a device for pivotally driving slats that comprises : -- a drive carriage that is movable in translation in both directions along a longitudinal direction (L) orthogonal to the pivot axes (AVP) of the slats and over a determined path between a first end position to which it is elastically returned and a second end position; -- a mechanism for converting the longitudinal movements of the drive carriage into simultaneous pivotal movements of the slats ; -- a controlled actuator of the movements of the drive carriage which comprises a variable-length member made of a shape-memory material, the length whereof varies as a function of its temperature, a first end whereof is connected to a fixed anchoring point , and the other end whereof is connected to the drive carriage ; -- means for controlling the variation in the temperature of the variable-length member of the actuator in order to cause movements of the drive carriage between its two end positions; -- a drive carriage that is movable in translation in both directions along a longitudinal direction (L) orthogonal to the pivot axes (AVP) of the slats and over a determined path between a first end position to which it is elastically returned and a second end position; -- a mechanism for converting the longitudinal movements of the drive carriage into simultaneous pivotal movements of the slats ; -- a controlled actuator of the movements of the drive carriage which comprises a variable-length member made of a shape-memory material, the length whereof varies as a function of its temperature, a first end whereof is connected to a fixed anchoring point , and the other end whereof is connected to the drive carriage ; -- means for controlling the variation in the temperature of the variable-length member of the actuator in order to cause movements of the drive carriage between its two end positions; - a retracted position; - and an active blocking position wherein, against an elastic biasing force applied to the drive carriage , the controlled adjustment block immobilizes, directly or indirectly, the drive carriage in an intermediate longitudinal position between its two end positions. <EOS>