Process parameter spatial inhomogeneities inside cell culture bioreactors has attracted considerable attention, however, few technologies allow investigation of the impact of these variations on process yield. Commercially available sensing probes sit at fixed locations, failing to capture the spatial distribution of process metrics. The bio-Processing online device (bPod) addresses this problem by performing real-time in situ monitoring of dissolved oxygen (DO) within bioreactor cell cultures. The bPod is an integrated system comprised of a potentiostat analog-front-end, a Bluetooth Low Energy microcontroller, and a Clark-type electrochemical DO sensor. The Clark-type sensor uses chronoamperometry to determine the DO percent saturation within a range relevant for mammalian cell culture. The free-floating capsule is packaged inside a 3D-printed biocompatible shell and wirelessly transmits data to a smartphone while submerged in the reactor. Furthermore, the bPod demonstrated a sensitivity of 37.5 nA/DO%, and can be adapted to multiple sensor types, enabling numerous bioprocess monitoring applications.