Very Low Frequency (VLF) radio waves propagate long distances with relative low attenuation showing stable phase and amplitude. Since VLF waves are efficiently reflected by the lower ionosphere, their propagation parameters provide information about electrical properties of this ionospheric region. Therefore, VLF remote sensing is widely used for sounding the lower ionosphere and study ionospheric disturbances related to terrestrial, solar and extrasolar phenomena. A new VLF radio waves receiver is under development using the RedPitaya platform, an open-source embedded system architected around the Zynq 7010 System on Chip, with analog-to-digital and digital-to-analog converters. We implemented the Software Defined Radio on the platform which covers bandwidth ranging from 20 kHz to 30 kHz. The receiver has been tested by tracking VLF signals from transmitters at 21.4 kHz (NPM, Hawaii) and 24 kHz (NAA, Cutler).