6S Power Module

Owned by Bryan Ma
Last updated: 2024-11-18
2 min read

Specifications (from the EE Team)

Overall Hardware Architecture (taken from https://uwarg-docs.atlassian.net/wiki/x/AoCsmQ )

Background

The drone uses a battery pack containing 12 cells, where 2 groups of 6 cells are each connected in series (hence 6S).

Each group of 6 cells is connected to a battery monitoring circuit.

This circuit measures:

  • The voltage of each cell

  • The current delivered by the group

And it sends:

We are not exactly sure of everything yet.

  • Battery-related information relating to the voltages and currents

  • The voltage and current information are sent as 2 analog signals, which our microcontroller converts to digital ones via an Analog-to-Digital Converter (ADC).

  • Some other information is sent via the I2C protocol

Description

  • MCU (STM32xX) in the top right is the microcontroller that we are writing the code to

  • Its job is to translate the messages it receives from the BQ76925 6s LiPo Battery Monitor boards and send the corresponding messages to the flight controller (FC) using the CAN protocol

The FC needs this information to make other decisions, e.g. if a part is consuming too much power, or when to land

Specific Hardware Information (taken from https://uwarg-docs.atlassian.net/wiki/x/HYBXq)

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MCU Schematics

 Current Roadblocks

Tasks Break Down:

 Action Items

etc.

 Milestones

Understand project specifications
Understand the I2C protocol
Understand the CAN protocol
Understand DroneCAN
etc.

Open Questions

  • Are our speculated ports correct?

  • What is transmitted over I2C?

  • What is the voltage range for the signals our MCU receives for the voltage and current info from the battery monitoring circuits?

  • How should the MCU beacon itself to the FC (i.e. so that the FC is aware that the MCU on the power module is there)?

  • What should be sent over CAN?

 

 Reference materials

Relevant protocols