Power.L.1N

Power.L.1N tile driver — Nordic nPM1300 PMIC.

Battery charger + 2 buck regulators + system supply (VSYS) + 3 indicator LEDs. Platform-agnostic: all bus access goes through tiles_pal_t.

The bucks come up at fixed boot voltages chosen by the tile's VSET pulldown resistors (no I2C needed): VSET1 = 47 kΩ → VOUT1 = 1.8 V, VSET2 = 330 kΩ → VOUT2 = 3.3 V. buck_set_mv() switches a buck to software control to override its VSET default at runtime.

Tile LEDs. Three discrete 0201 parts (Power-L1-N-a BOM), not an RGB package: U3 = APG015SURKKC-TT 631 nm red U4 = APG015SEKKC-TT 605 nm ORANGE (previously documented as "yellow") U5 = APG015CGKKC-TT 571 nm green

Which LED is which (confirmed 2026-09-24): red, orange, green sit left to right on the nPM1300's A1, A2, A3 balls, which are LED0, LED1, LED2 (WLCSP pin table). So LED0 = red (U3), LED1 = orange (U4), LED2 = green (U5).

Driver mode assignment made by init() (the chip's own reset assignment): LED0 red → ERROR mode (auto, on for charger faults) LED1 orange → CHARGING mode (auto, on while charging) LED2 green → HOST mode (firmware "ready"/status, via led_set())

Before 1.2.0 init() had this backwards (LED0 HOST, LED2 ERROR, from a misread schematic), so a charger fault lit the green LED and firmware status the red one.

Vibe Settings

What Studio’s Vibe interface lets you change on this tile, in plain language or from the tile inspector. Each one is an argument of a driver function below, so the same setting is available from Blocks, the DSL and C. Basic settings are shown by default; advanced ones sit behind the inspector’s Advanced toggle.

Setting	Tier	Values	Default	Function
Charge the battery	basic	on / off	on	charger_enable(on)
USB input limit	basic	100 to 1500 mA	500	set_vbus_limit_ma(ma)
Charge current	basic	32 to 800 mA	100	set_charge_current_ma(ma)
Charge to	advanced	3.5 to 4.45 V	4200	set_term_mv(mv)

Examples

Quick start

  #include "core_tiles.h"

  tile_t pmic;
  tile_power_l_1n_init(core_tiles_pal(&core_i2c1), 0, &pmic, NULL);
  if (tile_is_ready(&pmic)) {
      tile_power_l_1n_set_charge_current_ma(&pmic, 200);
      tile_power_l_1n_charger_enable(&pmic, 1);
      uint16_t vbat = tile_power_l_1n_get_vbat_mv(&pmic);
      (void)vbat;
  }

API reference

Initialization

tile_power_l_1n_find

uint8_t tile_power_l_1n_find(tiles_pal_t* hal, uint8_t instance)

Check whether an nPM1300 is present on the I2C bus.

hal: Platform HAL handle
instance: Instance index (0 = default, see mapping table)

Returns 1 if the device ACKs, 0 otherwise

tile_power_l_1n_init

void tile_power_l_1n_init(tiles_pal_t* hal, uint8_t instance, tile_t* tile, const power_l_1n_cfg_t* cfg)

Sets the indicator LED modes (LED0 red = ERROR, LED1 orange = CHARGING, LED2 green = HOST), disables NTC monitoring (no thermistor on this tile), and applies the charger settings. The buck regulators are left at their boot voltages (1.8 V / 3.3 V, fixed by the VSET resistors) — they are already up. Pass cfg=NULL for defaults (500 mA USB limit, 100 mA, 4.20 V, charging enabled). A zero-initialised cfg is NOT the same as NULL: it leaves charging OFF (enable_charging = 0). 4.20 V and at least ~100 mAh (100 mA is 1C for a 100 mAh cell). They are NOT safe for a LiFePO4 cell (charge to 3.60 V: pass term_mv = 3600) or for a smaller cell (lower charge_current_ma to <= 1C). The chip itself powers up with charging disabled at 3.60 V / 32 mA; init() is what raises it.

hal: Platform HAL handle
instance: Instance index (0 = default, see mapping table)
tile: Pointer to tile handle (populated by this function)
cfg: Optional config, or NULL for defaults

Runtime

tile_power_l_1n_get_charge_status

Studio

uint8_t tile_power_l_1n_get_charge_status(tile_t* tile)

Read the raw charge-status register.

Returns BCHGCHARGESTATUS bits (NPM1300_CHG_* mask).

tile_power_l_1n_get_charge_error

Studio

uint8_t tile_power_l_1n_get_charge_error(tile_t* tile)

Read the charger error-reason register.

Returns BCHGERRREASON bits (0 = no error).

tile_power_l_1n_is_charging

Studio

uint8_t tile_power_l_1n_is_charging(tile_t* tile)

Whether the charger is actively charging (trickle / CC / CV).

Returns 1 if charging, 0 otherwise.

tile_power_l_1n_is_charge_complete

Studio

uint8_t tile_power_l_1n_is_charge_complete(tile_t* tile)

Whether charging has completed (battery full).

Returns 1 if charge complete, 0 otherwise.

tile_power_l_1n_battery_present

Studio

uint8_t tile_power_l_1n_battery_present(tile_t* tile)

BATTERYDETECTED in BCHGCHARGESTATUS, a charger-domain bit: the datasheet states "CHARGER waits until a battery is detected before charging", i.e. detection runs as part of the charge cycle. With the charger disabled the bit reads 0 whether or not a cell is fitted — measured on the bench with a battery physically attached (0 before enable, 1 after). Do NOT gate a charge-enable decision on this; that deadlocks. Enable charging first, poll this for a second or two, and disable again if nothing appears. Note also that get_vbat_mv() cannot substitute: an open battery terminal reads a plausible ~3 V once charger current has pushed the VBAT decoupling cap up.

Returns 1 if a battery is present, 0 otherwise.

tile_power_l_1n_get_vbat_mv

Studio

uint16_t tile_power_l_1n_get_vbat_mv(tile_t* tile)

Measure the battery voltage.

Returns VBAT in millivolts (0-5000).

tile_power_l_1n_get_vsys_mv

Studio

uint16_t tile_power_l_1n_get_vsys_mv(tile_t* tile)

Measure the system (VSYS) voltage.

Returns VSYS in millivolts (0-6375).

tile_power_l_1n_get_die_temp_c

Studio

int16_t tile_power_l_1n_get_die_temp_c(tile_t* tile)

Measure the PMIC die temperature.

Returns Die temperature in degrees Celsius.

tile_power_l_1n_led_set

Studio

void tile_power_l_1n_led_set(tile_t* tile, uint8_t led, uint8_t on)

Only effective when the LED is in HOST mode (see led_set_mode).

led: 0, 1 or 2.
on: 1 = on, 0 = off.

Config

tile_power_l_1n_charger_enable

Studio

void tile_power_l_1n_charger_enable(tile_t* tile, uint8_t on)

Enable or disable battery charging.

on: 1 = enable charging, 0 = disable.

tile_power_l_1n_set_vbus_limit_ma

Studio

void tile_power_l_1n_set_vbus_limit_ma(tile_t* tile, uint16_t ma)

The nPM1300 powers up with a 100 mA input limit; init() raises it to 500 mA (what any USB port gives) unless the config says otherwise. The limit caps what is drawn from USB for the system AND the charger together. It does not regulate VSYS: with a battery attached, asking for more than the limit gives cuts the charge back and lets VSYS fall to just above the battery voltage (measured: a 100 mA charge on the 100 mA limit took VSYS from 5.15 V to ~3.65 V; both bucks held, but with only ~350 mV of headroom on 3.3 V, which a load with a start-up surge can dip). With no battery, VSYS simply sags. The chip falls back to its START-UP limit whenever VBUS is removed, which matters for exactly the system that charges: one with a battery keeps running through an unplug, and would otherwise be back at 100 mA on re-plug. So this writes the start-up limit too, and the value holds until the chip is RESET (when it returns to 100 mA, and init() sets it again). Settable 100-1500 mA in 100 mA steps; a request is rounded DOWN to a step (never more than asked) and clamped to that range. 100 and 500 mA are the USB-compliant, accurately trimmed levels; 500 mA is safe for any USB port.

ma: [100..1500] mA Input current limit, in milliamps.

tile_power_l_1n_set_charge_current_ma

Studio

void tile_power_l_1n_set_charge_current_ma(tile_t* tile, uint16_t ma)

Programmable 32-800 mA in 2 mA steps (rounded down); out-of-range values clamp. The chip only accepts a new current while the charger is disabled (datasheet §6.2.4), so if charging is on this pauses it for the write and re-enables it. Keep it at or below 1C for the cell fitted.

ma: [32..800] mA Charge current in milliamps.

tile_power_l_1n_set_term_mv

Studio

void tile_power_l_1n_set_term_mv(tile_t* tile, uint16_t mv)

Selectable 3.50-3.65 V or 4.00-4.45 V in 50 mV steps; the 3.70-3.95 V gap is not supported and clamps to 3.65 V.

mv: [3500..4450] mV Termination voltage in millivolts (e.g. 4200).

tile_power_l_1n_buck_enable

Studio

void tile_power_l_1n_buck_enable(tile_t* tile, uint8_t buck, uint8_t on)

Enable or disable a buck regulator.

buck: 1 (VOUT1) or 2 (VOUT2).
on: 1 = enable, 0 = disable.

tile_power_l_1n_buck_set_mv

Studio

void tile_power_l_1n_buck_set_mv(tile_t* tile, uint8_t buck, uint16_t mv)

Selects software voltage control for that buck (overriding its VSET resistor) and applies the new target.

buck: 1 (VOUT1) or 2 (VOUT2).
mv: [1000..3300] Output voltage in mV, 100 mV steps.

tile_power_l_1n_led_set_mode

Studio

void tile_power_l_1n_led_set_mode(tile_t* tile, uint8_t led, power_l_1n_led_mode_t mode)

In auto modes (ERROR/CHARGING) the charger drives the LED directly; HOST mode hands control to led_set(). LED0 is red, LED1 orange, LED2 green (see the file header). init() leaves LED2 in HOST mode for firmware status.

led: 0, 1 or 2.
mode: power_l_1n_led_mode_t.

Advanced

tile_power_l_1n_get_reset_cause

Studio

uint8_t tile_power_l_1n_get_reset_cause(tile_t* tile)

Read the reset-cause register (why the PMIC last reset).

Returns RSTCAUSE bits.

Driver gaps · 6

Chip capabilities this driver doesn’t expose yet.

advancedNTC battery thermistorHardware-gated (not a driver gap). The nPM1300 can sense battery temperature via an NTC thermistor for JEITA charge regulation. NTC is tied to GND on Power-L-1N-a (no thermistor fitted), so the driver disables NTC monitoring (ADCNTCRSEL=0, DISABLENTC). Closing requires a tile hardware revision.

nicheLoad switches / LDOs (LSIN/LSOUT)Hardware-gated (not a driver gap). The nPM1300's two load-switch/LDO outputs are tied off (LSIN1/2, LSOUT1/2 grounded) on this tile, so there's nothing to control.

nicheGPIO0-3Hardware-gated (not a driver gap). The nPM1300 GPIOs aren't routed to tile pads on Power-L-1N-a, so there's no externally useful GPIO function.

advancedShip / hibernate modeDriver-deferred. The chip supports ultra-low-power ship (370 nA) and hibernate modes that isolate the battery for storage (datasheet §7.4: TASKENTERSHIPMODE 0x0B02, TASKENTERHIBERNATE 0x0B00). Not yet exposed. The SHPHLD wake button is not routed to a pad on Power-L-1N-a, so the only way back out of ship mode on this tile is applying CHG (VBUS), which needs a bench check before it is offered as a Studio call.

nichePOF warning + buck retention / forced-PWMDriver-deferred. Power-fail early-warning (via GPIO) and buck retention-voltage / forced-PWM modes aren't exposed yet.

advancedUSB-C source detection (CC1 / CC2)Driver-deferred. The nPM1300 reports what the attached source can supply (USBCDETECTSTATUS: default / 1.5 A / 3 A) and the tile routes CC1 / CC2 to pads 2 / 3, but the driver does not read it. set_vbus_limit_ma() therefore takes the caller's word for what the source can give: 500 mA is safe for any USB port, more is only safe for a supply known to deliver it.

Events

charge_complete
charging

Enums

power_l_1n_led_mode_t

LED indicator mode (LEDDRVxMODESEL).

NPM1300_LED_ERROR: auto: on for charger error
NPM1300_LED_CHARGING: auto: on while charging
NPM1300_LED_HOST: software-controlled via led_set()
NPM1300_LED_NOTUSED: disabled

Constants

TILE_POWER_L_1N_VERSION_MAJOR	1
TILE_POWER_L_1N_VERSION_MINOR	2
TILE_POWER_L_1N_VERSION_PATCH	0
NPM1300_I2C_ADDR	0x6B