The paper presents a teaching experiment using the LOGO language to introduce geometric programming to architectural students with no a priory coding knowledge. Based on extreme simplicity as well as instant visual feedback, the language allows to introduce core programming concepts with little technicality. The extension of the language to a 3D space triggers designers interest and creativity while the introduction of a simple robotic drawing machine confront them with a simple fabrication context. These elements concur to develop a critical approach of the use of digital tools in the architectural design process, with the underlying aim to raise the students awareness on the implication of tooling on their design practice.