LoveRPi PoE HAT with PWM Fan Controller

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LoveRPi PoE HAT with PWM Fan Controller is designed for the following boards:

  1. Raspberry Pi 3 Model B+
  2. Raspberry Pi 4 Model B

It comes in three variants:

  1. 802.3af without isolation
  2. 802.3af with 3KV isolation
  3. 802.3at with 3KV isolation

All are designed for commercial operating temperature and humidity range.

802.3af without isolation

  • 15.4W PSE
  • 12.95W PD
  • 10.1W DC
  • relative ground plane will create ground loop if connected to different ground plane
  • must not be used with grounded HDMI or USB devices
  • ethernet cabling must be carefully selected to not mix relative ground planes

802.3af with isolation

  • 15.4W PSE
  • 12.95W PD
  • 10.1W DC
  • 3 kilovolt galvanic isolation transformer
  • transformer noise shielding

802.3at with isolation

  • 30W PSE
  • 25.5W PD
  • 20.4W DC
  • 3 kilovolt galvanic isolation transformer
  • transformer noise shielding

PWM Fan Controller

  • I2C bus address on 40-pin header pin 3 and 5
  • SMBUS compliant
  • compatible with 4-pin header PWM fans
  • 5V DC (12V fans will have lower top speed)
  • 26 KHz High Speed PWM
  • 9.5 Hz to 2.24 KHz Low Speed PWM
  • Spin Up and Ramp Rate Control
  • 1% accuracy from 500 RPM to 16 KRPM

Installation

  1. Start with a bare board without any heatsinks. Clear the board of any obstructions.
  2. Overlay the PoE HAT on the board and align the 4-pin PoE header with the PoE HAT 4-pin connector. Align the first 6 pins of the 40-pin header with the the PoE HAT 6-pin connector.
  3. Push down until the HAT is fully seated on the board. Check from the side to make sure that the HAT is fully seated on the header for both the 4-pin and 6-pin connectors.
  4. Attach heatsink for the main SoC only. This is the only chip that needs a heatsink.
  5. Attach PWM fan to the header on the PoE HAT.

Configuration

To enable on Raspbian OS, add the following to /boot/config.txt under [all] section.

dtoverlay=i2c-fan,emc2301
1 Like
2

i’m having issues with my fan changing based on temperature, it just goes full throttle 24/7. any suggestions?

edit: i see, i have this

but need this

3

The model without the fan controller requires you to use fixed voltages to adjust the RPM. You can attach the red wire to 3.3V to lower the normal speed. However, there is no fan control based on temperature.

4

@LoveRPi ah, okay. are they about the same size; the fan controlled poe vs non-fan control poe?

5

Yes, they are roughly the same size. We do not recommend using the non-isolated model for general use.

No Fan Controller Model

Fan Controller Model

Click the 3KV to see the differences.

1 Like
7

i ordered these, but it doesn’t seem like they’re turning on.
https://www.amazon.com/dp/B0BJFCBJXX

i connected the black wire to ground, red to power, and blue to rpm. is that correct?

this is what i see when i do:
watch -n 1 "grep -s . /sys/class/thermal/thermal_zone*/* /sys/class/thermal/cooling_device*/*"

/sys/class/thermal/thermal_zone0/available_policies:step_wise
/sys/class/thermal/thermal_zone0/cdev0_trip_point:0
/sys/class/thermal/thermal_zone0/cdev0_weight:0
/sys/class/thermal/thermal_zone0/cdev1_trip_point:1
/sys/class/thermal/thermal_zone0/cdev1_weight:0
/sys/class/thermal/thermal_zone0/integral_cutoff:0
/sys/class/thermal/thermal_zone0/k_d:0
/sys/class/thermal/thermal_zone0/k_i:0
/sys/class/thermal/thermal_zone0/k_po:0
/sys/class/thermal/thermal_zone0/k_pu:0
/sys/class/thermal/thermal_zone0/mode:enabled
/sys/class/thermal/thermal_zone0/offset:410040
/sys/class/thermal/thermal_zone0/policy:step_wise
/sys/class/thermal/thermal_zone0/slope:-487
/sys/class/thermal/thermal_zone0/sustainable_power:0
/sys/class/thermal/thermal_zone0/temp:48686
/sys/class/thermal/thermal_zone0/trip_point_0_hyst:2000
/sys/class/thermal/thermal_zone0/trip_point_0_temp:75000
/sys/class/thermal/thermal_zone0/trip_point_0_type:active
/sys/class/thermal/thermal_zone0/trip_point_1_hyst:2000
/sys/class/thermal/thermal_zone0/trip_point_1_temp:50000
/sys/class/thermal/thermal_zone0/trip_point_1_type:active
/sys/class/thermal/thermal_zone0/trip_point_2_hyst:0
/sys/class/thermal/thermal_zone0/trip_point_2_temp:110000
/sys/class/thermal/thermal_zone0/trip_point_2_type:critical
/sys/class/thermal/thermal_zone0/type:cpu-thermal
/sys/class/thermal/cooling_device0/cur_state:0
/sys/class/thermal/cooling_device0/max_state:10
/sys/class/thermal/cooling_device0/type:emc2305_fan

ah, i think i got it. plugged into pwm instead of rpm.

8

PWM fans are 4-wire. That fan is 3-wire so it is not a standard PWM fan.