What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED AND THE AIRCRAFT RETURNED TO CLT DUE TO THE FLIGHT CREW REPORTING THAT ON TAKEOFF A LANDDING GEAR NOT UPLOCKED ECAM DISPLAYED THE NOSE INDICATED RED. THE FLIGHT CREW CYCLED LEVER DOWN, NO GEAR CAME DOWN. CYCLED UP, MAIN CAME UP, NOSE GEAR INDICATED RED. CYCLED BACK DOWN, GEAR SLOWLY CAME DOWN WITH ALL THREE GREEN. THE AIRCRAFT LANDED SAFELY AT CLT AND TAXIED TO THE GATE UNDER ITS OWN POWER. MAINTENANCE REPLACED PROXIMITY SENSORS 33GA AND 35GA PER AMM 32-31-73 AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK WITH NO ISSUES NOTED.