MaixCAM MaixPy Power Management Unit

Warning !!!
Setting incorrect voltages may damage the MaixCAM-Pro. Do not modify the voltages of DCDC2~DCDC5, ALDO1~ALDO4, and BLDO1~BLDO2 unless you fully understand the purpose and consequences of the adjustment.

1. Introduction#

The MaixCAM-Pro is equipped with the AXP2101 Power Management Unit (PMU), providing multi-channel power outputs, charging management, and system protection functions. The AXP2101 supports linear charging and features 5 DC-DC channels and 11 LDO channels, meeting a variety of power requirements. It also comes with multiple-channel ADCs for real-time monitoring of voltage and temperature, and integrates protection features such as over-voltage, over-current, and over-temperature to ensure system stability and safety.

The MaixCAM does not have an onboard power management unit. If power management functionality is required, please connect an external power management unit.

2. Using Power Management Unit in MaixPy#

Operate the AXP2101 device using the PMU module.

Example:

from maix import time, app
from maix.ext_dev import pmu

p = pmu.PMU("axp2101")

# Get battery percent
print(f"Battery percent: {p.get_bat_percent()}%")

# Set the max battery charging current
p.set_bat_charging_cur(1000)
print(f"Max charging current: {p.get_bat_charging_cur()}mA")

# Set DCDC1 voltage (!!! Do not modify the voltage of other channels,
# as it may damage the device.)
old_dcdc1_voltage = p.get_vol(pmu.PowerChannel.DCDC1)
print(f"Old DCDC1 voltage: {old_dcdc1_voltage}mV")
p.set_vol(pmu.PowerChannel.DCDC1, 3000)
new_dcdc1_voltage = p.get_vol(pmu.PowerChannel.DCDC1)
print(f"New DCDC1 voltage: {new_dcdc1_voltage}mV")

# Get all channel voltages
channels = [
    pmu.PowerChannel.DCDC1, pmu.PowerChannel.DCDC2, pmu.PowerChannel.DCDC3,
    pmu.PowerChannel.DCDC4, pmu.PowerChannel.DCDC5, pmu.PowerChannel.ALDO1,
    pmu.PowerChannel.ALDO2, pmu.PowerChannel.ALDO3, pmu.PowerChannel.ALDO4,
    pmu.PowerChannel.BLDO1, pmu.PowerChannel.BLDO2
]

print("------ All channel voltages: ------")
for channel in channels:
    print(f"{channel.name}: {p.get_vol(channel)}")
print("-----------------------------------")

# Poweroff (Important! Power will be cut off immediately)
# p.poweroff()

while not app.need_exit():
    time.sleep_ms(1000)

You can also use the AXP2101 module to configure the power management unit. The usage is similar to the PMU module, and you can refer to the example script axp2101_example.py for guidance.

Initialize the PMU object, and call get_bat_percent() to get the current battery level. Call set_bat_charging_cur() to set the maximum charging current.

Calling poweroff() will immediately cut off power to the device. Please ensure that data in memory is synced to disk before using this function.

You can use the set_vol() and get_vol() methods to set and read the voltage of the DC-DC and LDO channels, respectively. Currently, the following channels of the AXP2101 are supported for voltage configuration: DCDC1~DCDC5, ALDO1~ALDO4, and BLDO1~BLDO2.

Warning !!!
Setting incorrect voltages may damage the MaixCAM-Pro. Do not modify the voltages of DCDC2~DCDC5, ALDO1~ALDO4, and BLDO1~BLDO2 unless you fully understand the purpose and consequences of the adjustment. If you need to test, please use the DCDC1 channel.

For detailed information on the PMU API, please refer to the PMU API Documentation

1. Introduction
2. Using Power Management Unit in MaixPy