K5C_Board_Power_Supply

The K5C board supports multiple power supply methods. Verify hardware version compatibility!

Power Supply Method	Voltage	Board Support
DC	12V	>= V1.0
Type-C	5V	>= V1.1
POE	12V	>= V1.0
BAT	> 3.7V	>= V1.2

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DC Power Supply

image-20250508092200565

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Type-C Power Supply

image-20250508092317387

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POE Power Supply

The board cannot directly support POE and requires an external POE module. Below is an example using a pin-header isolated POE module.

12V1A Pin-Header Isolated POE Module

image-20250508093405234

image-20250508095010489

POE Module Interface

Warning: Ensure VCC12V is connected correctly. Incorrect wiring may damage the board!

image-20250508094612067

POE Power-On Steps

1. Connect the POE module:

2. Connect a POE-enabled Ethernet cable. Check if the board powers on normally and LEDs function properly. Disconnect immediately if LEDs behave abnormally!

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BAT (Battery) Power Supply

Battery Interface

Connect the battery’s positive terminal to VBAT and negative terminal to GND as labeled on the board:

Battery Power-On Steps

1. Connect the battery according to the silk-screen labels:

2. Press and hold the Power button to turn on the board. Check LED status. Disconnect the battery immediately if LEDs behave abnormally!

Note: The board can only be powered on via the Power button when using battery supply.

Battery Charging

• The battery can be charged via Type-C or DC interfaces.

• If both interfaces are connected, DC charging takes priority.

Software Configuration

Device Tree (DTS) Configuration Path:

longan/device/config/chips/a133/configs/c3/kickpi-k5c.dts

Battery Node:

battery_power_supply: battery-power-supply {
    compatible = "x-powers,axp803-battery-power-supply";
    status = "okay";

    pmu_chg_ic_temp = <0>;
    pmu_battery_rdc= <93>;
    pmu_battery_cap = <5067>;
    pmu_runtime_chgcur = <1000>;
    pmu_suspend_chgcur = <2000>;
    pmu_shutdown_chgcur = <2000>;
    pmu_init_chgvol = <4200>;
    pmu_battery_warning_level1 = <15>;
    pmu_battery_warning_level2 = <0>;
    pmu_chgled_func = <0>;
    pmu_chgled_type = <0>;
    ocv_coulumb_100 = <1>;
    pmu_bat_para1 = <0>;
    pmu_bat_para2 = <0>;
    pmu_bat_para3 = <0>;
	......
    pmu_bat_para31 = <100>;
    pmu_bat_para32 = <100>;

    pmu_bat_temp_enable = <0>;
    pmu_bat_charge_ltf = <1105>;
    pmu_bat_charge_htf = <121>;
    pmu_bat_shutdown_ltf = <1381>;
    pmu_bat_shutdown_htf = <89>;
    pmu_bat_temp_para1 = <2814>;
    pmu_bat_temp_para2 = <2202>;
	......
    pmu_bat_temp_para16 = <66>;

    wakeup_bat_out;
    /* wakeup_bat_in; */
    /* wakeup_bat_charging; */
    /* wakeup_bat_charge_over; */
    /* wakeup_low_warning1; */
    /* wakeup_low_warning2; */
    /* wakeup_bat_untemp_work; */
    /* wakeup_bat_ovtemp_work; */
    /* wakeup_bat_untemp_chg; */
    /* wakeup_bat_ovtemp_chg; */
};

Debugging Commands

$ echo 8 > /proc/sys/kernel/printk
$ echo 0xf > /sys/class/axp/debug_mask

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FAQs

Type-C Power Supply Issues

1. Verify hardware compatibility: Check if the Type-C interface has a 0Ω resistor on the back (see below). Purpose of 0Ω resistor: Enables Type-C power supply.

2. Check power adapter: Ensure the Type-C charger provides sufficient power. Try replacing the charger.

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System Fails to Enter Sleep Mode

Case 1: Check if the board is connected via ADB over Type-C. Case 2: Verify "fake sleep" configuration:

console$ getprop persist.sys.kickpi_holding_wakelock 

Enable fake sleep (only turns off the screen):

console$ setprop persist.sys.kickpi_holding_wakelock true

Disable fake sleep:

console$ setprop persist.sys.kickpi_holding_wakelock false

Default software configuration:

--- a/android/device/softwinner/ceres-c3/ceres_c3.mk
+++ b/android/device/softwinner/ceres-c3/ceres_c3.mk
+PRODUCT_SYSTEM_DEFAULT_PROPERTIES += \
+    persist.sys.kickpi_holding_wakelock=true