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

DC Power Supply

image-20250508092200565

Type-C Power Supply

image-20250508092317387

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!

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

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.

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

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