This research investigates the feasibility of a sensor patch for newborns. A sensor patch would be a device that is applied to the skin of the newborn. It can monitor the patient's temperature, heart rate, respiration rate, oxygen saturation and asses its general appearance of the skin so that it can check the newborn for jaundice. It should then communicate wirelessly to a base station which should have a compatible communication protocol. What happens after receiving of sensor data at the base station is beyond the scope of this project. One of the major challenges in the design process is energy efficiency, since the device should be small enough to fit on a baby and the battery should thus also be small. Additionally, the sensor patch should be able to operate for 3 days continuously. The overall design comprises sensors, a battery with battery control system, a microcontroller and a communication module. The overall design is split up over three reports. This report focuses on implementing the microcontroller and communication protocol. It is found that using a design with separate microcontroller and communication device is more efficient than using a so-called System on Chip where all of this is mounted on a single device. Then a comparison between different microcontrollers, communication protocols and communications devices is made. It is found that a design with an MSP430FR5994, Bluetooth Low Energy protocol and RSL10 communication chip fits the requirements best. The research concludes that with the chosen hardware it is possible to meet the set requirements for the subsystem. Further research still needs to be done towards optimising software for the chosen devices.