The STM32F030/NRF24L01+ low power sensor node has been running since August 14 on a pair of cheap generic AA batteries. The node transmits data (brightness) every second and will retry up to 15 times if it fails to get an ACK from the base station. For most of this time the base station has been off so those retries have been happening. Energy consumption has been much higher than it should have been nevertheless the device is still running.
