Signals from a plurality of sensing lines of a grid based digitizer sensor based is combined based on matrix multiplication with a Hadamard Matrix. The combining provides a plurality of signal combinations. Each of the plurality of signal combinations is sampled with a different Analog to Digital Converters (ADC) in a group of ADCs. The sampling is performed simultaneously. The sampled outputs from the group of ADCs are post processed including multiplying an inverse of the Hadamard Matrix with the sampled outputs from the group of ADCs. The presence of an object interacting with the grid based digitizer sensor is detected based on the post processing.