SLUUBW5A July 2018 – September 2021 BQ34Z100-G1
This appendix compares the communication timing specifications for the different battery fuel gauge and battery monitor products. It discusses some of the interface requirements necessary for robust HDQ communication, such as the need for a break prior to each communication, how to reliably read 16-bit dynamic values over the 8-bit bus, and the need for some noise filtering on the HDQ line. It also discusses the firmware strategy required for implementing the HDQ interface using a discrete I/O port, and describes the option of using a UART to handle the HDQ bit timing requirement.