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Rodeo

max17048.h

Generated from the header

This page is rodeo-sdk/common/max17048.h — its comments and declarations. To change it, change the header.

rodeo::max17048::Reading r = rodeo::max17048::Decode(vcell, soc, crate);
r.volts;          // 3.871
r.percent;        // 64.5
r.percent_per_hr; // +12.3 while charging, negative while running on the cell

The gauge sits on the cell (CELL and VDD on BATT_P) and works out the state of charge from the voltage alone, with no sense resistor. It can’t see USB power: the charger’s PGOOD and CHG only light the power board’s LEDs and don’t reach the Seed. Whether the cell is charging is read from the rate of change, which takes a minute or two to settle after the charger starts or stops.

max17048::kVcell

constexpr uint8_t kVcell = 0x02;

78.125 uV per bit

max17048::kSoc

constexpr uint8_t kSoc = 0x04;

1/256 % per bit

max17048::kMode

constexpr uint8_t kMode = 0x06;

max17048::kVersion

constexpr uint8_t kVersion = 0x08;

0x001x

max17048::kConfig

constexpr uint8_t kConfig = 0x0C;

max17048::kCrate

constexpr uint8_t kCrate = 0x16;

signed, 0.208 %/hr per bit

max17048::kVresetId

constexpr uint8_t kVresetId = 0x18;

max17048::kStatus

constexpr uint8_t kStatus = 0x1A;

max17048::kCommand

constexpr uint8_t kCommand = 0xFE;

max17048::kStatusResetIndicator

constexpr uint16_t kStatusResetIndicator = 1u << 8;

STATUS bits, in the 16-bit register.

max17048::kStatusVoltageHigh

constexpr uint16_t kStatusVoltageHigh = 1u << 9;

VH

max17048::kStatusVoltageLow

constexpr uint16_t kStatusVoltageLow = 1u << 10;

VL

max17048::kStatusVoltageReset

constexpr uint16_t kStatusVoltageReset = 1u << 11;

VR

max17048::kStatusSocLow

constexpr uint16_t kStatusSocLow = 1u << 12;

HD: SOC under CONFIG’s threshold

max17048::kStatusSocChange

constexpr uint16_t kStatusSocChange = 1u << 13;

SC: SOC moved by 1 %

max17048::kIdleBandPercentPerHr

constexpr float kIdleBandPercentPerHr = 1.0f;

Above this rate, either way, the cell counts as charging or discharging.

max17048::Word

constexpr uint16_t Word(const uint8_t b[2]);

A 16-bit register as the gauge sends it: big-endian.

max17048::Volts

constexpr float Volts(uint16_t vcell);

max17048::Percent

constexpr float Percent(uint16_t soc);

max17048::PercentPerHr

constexpr float PercentPerHr(uint16_t crate);

max17048::VersionOk

constexpr bool VersionOk(uint16_t version);

True if the VERSION register reads as a MAX17048/49.

max17048::Trend

enum class Trend : uint8_t
  • kIdle — full, or neither charging nor in use enough to tell
  • kCharging
  • kDischarging

max17048::Reading

struct Reading

Members

  • float volts
  • float percent — can read a little over 100 when full
  • float percent_per_hr
  • Trend trend

max17048::Decode

inline Reading Decode(uint16_t vcell, uint16_t soc, uint16_t crate);

max17048::TrendName

inline const char* TrendName(Trend t);