Raspberry Pi PiCoolFAN4 User manual

PiCoolFAN4 Firmware Code 0x14 Print Date 10.11.2019
Designed by www.pimodules.com manufactured in co-operation with www.thepihut.com
PiCoolFan 4
Advanced Active Raspberry Pi® Cooling System
with Hardware RTC
user LEDs, Sounder, Relay, IR and 1-wire interface
User Guide
Designed for the Raspberry Pi® 4 Model B
Compatible with
All former models of Raspberry Pi®
“Raspberry Pi” is a trademark of the Raspberry Pi® Foundation

PiCoolFAN4 Firmware Code 0x14 Print Date 10.11.2019
Designed by www.pimodules.com manufactured in co-operation with www.thepihut.com
Contents
SYSTEM OVERVIEW ...............................................................................................................................................3
INTRODUCTION..............................................................................................................................................................3
PICOOLFAN 4PCB LAYOUT ............................................................................................................................................4
SET UP PROCEDURE ...............................................................................................................................................5
WHAT’S IN THE BAG? .....................................................................................................................................................5
KIT ASSEMBLY ...............................................................................................................................................................6
USING A HEATSINK .........................................................................................................................................................8
BASIC FUNCTIONALITY...........................................................................................................................................9
FACTORY DEFAULTS........................................................................................................................................................9
IDENTIFYING THE CURRENT SETUP ...................................................................................................................................10
TUNING THE FACTORY DEFAULT TEMPERATURE THRESHOLD.................................................................................................11
ADVANCED FUNCTIONALITY ................................................................................................................................ 13
COOLING PROFILES.......................................................................................................................................................13
COOLING PROFILE PARAMETERS......................................................................................................................................14
HOW TO SET A COOLING PROFILE &PARAMETERS..............................................................................................................17
USING THE RASPBERRY PI TEMPERATURE SENSOR ..............................................................................................................18
LOW NOISE FAN COOLING TECHNIQUES ...........................................................................................................................20
I2C ADDRESS TABLE .....................................................................................................................................................21
ADDITIONAL FEATURE SETUP ..............................................................................................................................22
HW REAL TIME CLOCK..................................................................................................................................................22
SOUND GENERATION SYSTEM.........................................................................................................................................25
HIGH CURRENT RELAY...................................................................................................................................................26
USER LEDS.................................................................................................................................................................27
INFRA-RED RECEIVER INTERFACE.....................................................................................................................................28
ESD PROTECTED 1-WIRE INTERFACE ................................................................................................................................28
BOOTLOADER RESET PINS (4-PIN HEADER)........................................................................................................................28
SETTING FACTORY DEFAULTS............................................................................................................................... 29
BOOTLOADER OPERATIONS................................................................................................................................. 30
USING DIFFERENT I2C ADDRESS........................................................................................................................... 33
COMMON PROBLEMS & SOLUTIONS ................................................................................................................... 34
DOCUMENT REVISIONS........................................................................................................................................ 36
FIRMWARE REVISIONS.........................................................................................................................................36

PiCoolFAN4 Firmware Code 0x14 Print Date 10.11.2019
Designed by www.pimodules.com manufactured in co-operation with www.thepihut.com
System Overview
Introduction
The PiCoolFAN4 is an Advanced Active Cooling System designed for the Raspberry Pi 4 as an independent
and autonomous cooling system, and can be used with all models of Raspberry Pi.
The PiCoolFAN4 provides an enhanced cooling capability using an embedded fan and temperature sensor.
The PiCoolFAN4 temperature sensor is placed exactly 3.5 mm above the Raspberry Pi 4 CPU. This
guarantees accuracy and continuity, measuring the system temperature as close to the CPU environment
as possible.
The PiCoolFAN4 does not need any software installation (great for software such as KODI, which can also
make use of the IR interface) and requires simple assembly by the user. If required, users can make use of
the provided software to enable greater control of the fan and cooling profile –including noise reduction.
The provided software allows the user to select either the Raspberry Pi’s CPU temperature for fan
threshold control, or the included temperature sensor on the PiCoolFAN4 PCB. In addition to this, the
software also allows the user to select and edit different cooling profiles which allow either instant fan
changes (‘hard’ cooling) or gradual changes in speed in-line with temperature changes (‘mild’ cooling).
The PiCoolFAN4 does not use any GPIO pins - all communication with the Raspberry Pi is via I2C. This
leaves your GPIO pins free for your projects or other HATs, which can be stacked with the PiCoolFAN4.
The PiCoolFAN4 is compatible with heatsinks when using an additional 8mm header. This allows users to
benefit from both passive and active cooling at the same time.
Noise reduction is achieved through the use of a PWM fan. This allows the user to set the fan speed
depending of the temperature, dramatically decreasing noise generation to an absolute minimum.
The PiCoolFAN4 includes Air Circulation Technology –the fan forces cool air over the CPU, removes heat,
then the warm air escapes through the special circle openings on the PCB. This design guarantees proper
air circulation and maximizes the cooling efficiency even with low fan speeds (low noise).
The PiCoolFAN4 is standard equipped with:
•Battery Backed Hardware Real-time Clock (RTC) DS1307 (coin battery 1220 available separately)
•2 user programmable LEDs (Red and Green)
•3 System LEDs (Cold, Hot and fan running)
•ESD Protected 1-wire interface (5V/3V)
•Infra-Red Receiver interface (Infra-red receiver available separately)
The PiCoolFAN4 also includes mounting areas for the following features:
•High Current Relay Kit (available separately)
•Programmable sounder (available separately)

PiCoolFAN4 Firmware Code 0x14 Print Date 10.11.2019
Designed by www.pimodules.com manufactured in co-operation with www.thepihut.com
PiCoolFAN 4 PCB Layout

PiCoolFAN4 Firmware Code 0x14 Print Date 10.11.2019
Designed by www.pimodules.com manufactured in co-operation with www.thepihut.com
Set up Procedure
What’s in the Bag?
This package comes with everything you need to start using the PiCoolFAN4 right out of the box. It’s
assembled, tested and contains all required accessories. Minor assembly is required by the user and no
soldering is necessary.
Each Package contains the following parts:
1. Assembled PiCoolFAN4 PCB
2. 2mm Header and Jumper
3. Necessary fan screws (4), bolts(4) and plastic spacers(4)
Note: The kit includes a 2mm header and jumper, but this is only required for the rare scenario where the
user needs to reset the bootloader and is otherwise not necessary to be soldered.
The PiCoolFAN4 assembly requires a pair of scissors and a cross-head screwdriver.

PiCoolFAN4 Firmware Code 0x14 Print Date 10.11.2019
Designed by www.pimodules.com manufactured in co-operation with www.thepihut.com
Kit Assembly
1. Cut the bag on upper side by scissors and remove components from the bag:
2. Place the fan on the top of the PCB with the cable to the right. It is important to place the fan this
way, as there are slots on the PCB matching the fan position. Incorrect placement of the fan will
reduce cooling performance:

PiCoolFAN4 Firmware Code 0x14 Print Date 10.11.2019
Designed by www.pimodules.com manufactured in co-operation with www.thepihut.com
3. Turn the PCB and fan over, and screw the first two screws in opposing corners as per the image
below. At this stage there is no need to full tighten the screws, just a couple of turns in order to
keep the fan in place. Do not push the center of the fan –this could cause breakage.
4. Fit the remaining fan screws, and then tighten all of them (finger-tight –do not overtighten!)
5. Turn the PCB over again and connect the fan cable to the socket:

PiCoolFAN4 Firmware Code 0x14 Print Date 10.11.2019
Designed by www.pimodules.com manufactured in co-operation with www.thepihut.com
6. Screw the 4 x 7mm spacers to the rear of the PCB with the provided nuts as per the image
below:
7. Fit your PiCoolFAN4 on to the Raspberry Pi 4. For basic usage there is no need for any software
installation.
You are ready to go!
Using a Heatsink
It is possible to use a heatsink with the PiCoolFAN4 and the combination of these two cooling tools
provides excellent results.
To use a heatsink with the PiCoolFan4, the user needs to fit a GPIO header/extender to raise the height
of the PCB (as standard, the PCB is close to the Raspberry Pi CPU to ensure the included temperature
sensor can function as per design).
Users should ensure that the PiCoolFAN4 is 3.5mm away from the heatsink, and test/adjust cooling profile
thresholds to account for the different conditions (see page 13).
Alternatively, users can make use of the included software to use the Raspberry Pi temperature sensor
for fan control (see page 18).

PiCoolFAN4 Firmware Code 0x14 Print Date 10.11.2019
Designed by www.pimodules.com manufactured in co-operation with www.thepihut.com
Basic Functionality
Factory Defaults
The PiCoolFAN4 is set to a factory default state at production. These defaults are:
•Cooling profile = Mild
•Temperature sensor = PiCoolFAN4 temperature sensor
•Temperature threshold (ttemp) = 55°C (50°C if using new software version V1.3)
•Temperature step (tstep) = 1
Note: More information on these values and Cooling Profiles can be found on page 13
Fan LEDs
The PiCoolFAN4 is equipped with 3 System LEDs (Blue, Green, and Red) which are also enabled at this
factory default state:
•If the current temperature is above the threshold, the red LED will light
•If the current temperature is below the threshold, the blue LED will light
•If the fan is running, the green LED will light.
Note: Green LED is driven by PWM. The intensity of the LED will increase with the fan speed for a visual
indication of the current cooling requirements.
The user can change this factory setup whenever they like (see page 11), and they can also revert back to
factory settings at any time (see page 29).

PiCoolFAN4 Firmware Code 0x14 Print Date 10.11.2019
Designed by www.pimodules.com manufactured in co-operation with www.thepihut.com
Identifying the Current Setup
A simple script is provided which indicates the current setup alongside temperature readings.
The scripts can be downloaded at the following address and should be moved to the Raspberry Pi home
directory:
https://pimodules.com/download/picoolfan4-daemons-and-python-scripts
The user will likely need to enable I2C at this stage. This can be achieved by enabling I2C within the
interfacing section of the Raspi-config tool (sudo raspi-config).
With the scripts in place and I2C enabled, run the following command:
sudo python pcf4_status.py
The output of the command should be similar to the image below (albeit values may be different):
A description of each line can be found below:
•PCB/FM Version: Hardware and firmware version number
•System Mode: shows which sensor and cooling profile has been selected (see page 14)
•RPi Core Temperature: Temperature reading from the Raspberry Pi’s temperature sensor
•PCF4 Received Core Temp: Temperature reading from the Raspberry Pi’s temperature sensor
•PCF4 Internal Temp: Temperature reading from the PiCoolFAN4 temperature sensor
•PCF4 Threshold Temp: Current temperature threshold setting
•PCF4 Temp. Step: Current temperature step for Mild cooling profiles (see page 13)
•PCF4 Fan Speed: Current fan speed
•Running time: Time the script has been running