In this work, the dosimetric performance of several Commercial Of The Shelf photodiodes was studied. They were tested against gamma rays from a teletherapy source and were characterized with the aim of building a one-dimensional array of dosimeters able to measure the the spatial distribution of dose in a radiotherapy irradiation field. An embedded system comprising an array of 40 photodiodes and its acquisition electronics was built and tested. The dose resolution of each detector was 0.06 cGy and the spatial resolution of the system 0.5 cm.