Position awareness is a desirable feature for many applications of Wireless Sensor Networks. The Received Signal Strength Indication of a radio channel provides a feasible way of estimating distance between nodes because its use doesn't require any additional hardware but a radio transceiver. The main drawback of using RSSI is its instability and interference susceptibleness noticed in real environments. This work shows an evaluation of an implementation of a location algorithm for wireless sensor networks and presents improvements that substantially improve the trustworthiness in its results. The results show that adequately adjusted RSSI measurements can be successfully used for localization in Wireless Sensor Networks.