Fig. 16
From: An open-source platform for sub-\(\textrm{g}\), sub-\(\upmu\)A data loggers
Pressure tag circuit. The major architectural differences between the pressure tag and BitTag are the different sensors and the addition of a large (4 MB) NOR flash memory (at25xe). Due to additional energy requirements of the external flash relative to internal flash the net load capacitance (\(C_L\)) required is significantly higher 23 \(\upmu\)F vs. 5 \(\upmu\)F. Diode D enables charging battery B while Vcc is connected. Bipolar transistor Q provides isolation for the processor reset line. Note that power to the pressure sensor (lps27) is provided by a processor I/O pin. Supply and ground signals to major blocks and various passive components are elided for clarity