The real-time acquisition of relevant acoustic parameters in brass instruments' embouchure usually requires expensive measurement setups. This paper describes the operating principle as well as the preliminary design of a digital and connected mouthpiece, which makes it possible to 1. perform, 2. wirelessly transfer to a mobile device, and 3. process and display these measurements, in an easy way and at low cost. The digital mouthpiece is based on a standard mouthpiece equipped with several microelectronic components and sensors. It enables the measurement, while playing, of the separate forces exerted by the upper and lower lips on the mouthpiece and of the upstream and downstream pressure. The system also includes a microphone to identify and analyse the possible correlations between the applied forces, the measured pressures, the sound frequency, and the sound pressure level. In this paper, we also present the first experimental results obtained with the digital mouthpiece, in the frame of test runs conducted with musicians from the Gustav Mahler University in Austria.