This thesis describes a system for text input from handwriting using a conventional pen with a clip-on sensing unit. The clip-on unit is a wireless sensor node that collects data from a triaxial accelerometer and a triaxial gyroscope and transmits it to a conventional personal computer. The host computer then performs segmentation to handle continuous handwriting, followed by LSTM-based classification. Moreover, we use a lexicon-based corrector to increase the accuracy. Experimental results show our proposed system to achieve good accuracy and reasonable latency for interactive use.