Aquire battery information from the BQ3060

[ThirteenFish]

It generates lots of cool information about the batteries like voltage and temperature and stuff. We need to determine exactly what we want, create the code to get it, and then have this information sent to the FC over the RocketNet.

Additionally it has a bunch of safety features. We should see if we can read the status of them or get notifications of when they change, and then send this to the FC over the error channel.

[ThirteenFish]

The BQ3060 updates values once every second. These are the registers we are interested in.

• Danger: *
• Safety status : 0x51
• - expects 0s *
• Safety Alert : 0x50
• - expects 0s *
• PFAlert : 0x52
• - expects 0s *
• PFStatus : 0x53
• - expects 0s
• Info: *
• OperationStatus : 0x54
• - PRES (MSB)
• - XDSG (bit 5)
• - XDSGI (bit 4)
• - EDV2 (bit 3) *
• ChargingStaus : 0x55
• - XCHG (MSB)
• - CHGSUSP (14)
• - PCHG (13)
• - LTCHG
• - ST1CHG
• - ST2CHG
• - HTCHG
• - CB
• - everything else 0 *
• PackVoltage : 0x5a
• • 16bit mv
• AverageVoltage : 0x5d
• • 16b mv
• TS1Temperatrue : 0x5e
• TS2Temperatrue : 0x5f
• BatteryStatus : 0x16
• Temperature : 0x08
• Voltage : 0x09
• Current : 0x0a
• AverageCurrent : 0x0b
• RemaingingCapacity : 0x0f
• • mah
• FullChagreCapacity : 0x10
• • mah
• ChargingCurrent : 0x14
• ChargingVoltage : 0x15
• BatteryStatus : 0x16
• CycleCount : 0x17
• CellVoltage4...1 : 0x3c...0x3f

[DavidRamage]

State of Charge

MaxError 0x0c

• read only
• expected % margin of error - 1-100
• set to 100% on reset
• set to 2% con completion of learning cycle unless learning cycle is limited
• if it is limited it is set to 8%, unless it was below that
• MaxError increments by 1 every 4 cycles

Relative State of Charge 0x0d -read only -percentage of charge remaining

• fractions rounded up -if ROSCL bit is set, Relative State of Charge and Relative Capacity are held at 99% and display 100% when primary charge termination occurs
• if the bit is not set, this does not happen Absolute State of Charge -read only -0 - 100%, rounded up
• Fraction depends upon CapM flag
• CapM value 0 - Remaining Capacity/Design Capacity
• CapM value 1 - Remaining Capacity/Design Energy

Remaining Capacity - 0x0f

• read/write -16 bit unsigned
• expressed in mAh or 10 mWh depending upon CapM flag

Full Charge Capacity - 0x10

• read
• 0-65535
• predicted peak charging capacity
• expressed in charge or power depending upon CapM

Run Time To Empty - 0x11 -read -predicted battery life 0-65534 minutes

• 65535 indicates that the battery is not being discharged

Average Time to Empty - 0x12

• read
• est'd battery life in minutes based on average current
• 0-65534 minutes
• 65535 indicates battery is not discharging

Average Time To Full - 0x13 -read

• time in minutes to charge based on average current
• 0-65534
• 65535 - not charging

CapM

• Bit in the BatteryMode register (0x03)

AverageCurrent - 0x0b

• read
• average current across terminals over one minute
• mA?
• signed 16 bit number

AtRate - 0x04

• read/write
• part of a function call used to set the AtRate value used for other AtRate functions
• AtRate units are either mA or 10mW depending on CapM
• When positive, AtRateTimeToFull returns time to a full charge
• When negative, AtRateTimeToEmpty returns the value to empty the battery.
• When negative, AtRateOk will return a boolean value indicating if the battery can keep supplying AtRate current/power for the next 10 seconds

AtRateTimeToFull - 0x05

• read
• 0-65535 minutes to charge the battery
• 65535 - no charge/discharge

AtRateTimeToEmpty - 0x06

• read
• reports based on either constant current (LMLD=0) or constant power (LMLD-1)
• updated per second
• 0-65534 minutes
• 65535 - no charge/discharge

AtRateOk - 0x07

• read
• boolean

• 0 = true

SafetyAlert - 0x50

• read
• bit vector, see pg 77 of datasheet for all possible alerts
• items in the bit vector are nearing alarm threshold but haven't reached it

SafetyStatus - 0x51 -read

• returns status of first level safety features

PFAlert - 0x52

• read
• indicates pending safety issues that have not yet triggered a failure

PFStatus - 0x53

• read
• indicates source of permanent failure conditions.

[DavidRamage]

The registers SafetyAlert, PFAlert, and PFStatus respectively contain values for items which are nearing alert thresholds, pending safety issues which have not yet yet caused a failure, and permanent failures.

A possible way to handle these situations is to:

1. Have the read thread in BQ3060.c read each of these registers as it spins.
2. In the case of a nonzero read from any of them, an event for that particular register will fire. The event handler will take a particular action based on the nature of the alert or failure. It may be desirable to have specific events for specific alerts or failures to reduce the number of register reads.

[DavidRamage]

I talked with Andrew tonight. He said that in situations where there is anything wrong with the battery, it should prevent the rocket from arming if it isn´t already armed. If it is, it should just send the error state down the wire. I have created a branch called rnh_safety_events which polls all three of the safety registers. If any of them read nonzero an event is triggered. Right now this event just sends the contents of all three registers onto the wire. A todo item is to go over the arming code and add in the ability to prevent arming should the need arise.

[DavidRamage]

This is apparently fixed in commit 4990e651fec6e387d908d2d482c8872c81dfac1a