- Smart Fan HAT the Best Cooling Solution for Raspberry Pi
- 40x40x10mm fan with 6 CFM airflow
- Step-up 12V power supply for precise fan speed control
- PWM Controller modulates the fan to keep constant Pi temperature
- Draws less than 100mA of power
- Stackable to itself, 2 fans can be added to Raspberry Pi
- Fully stackable allows adding other cards to Raspberry Pi
- Uses only I2C interface, leaves full use of all GPIO pins
- Super quiet and efficient.
- Smart Fan Raspberry Pi
- Command Line Interface
- Python Library
- Python Example
- Node-RED node
A must for all mission critical installations
Due to semiconductor shortages, the current version of the Smart Fan does not have a processor. It implements PWM fan control over the I2C bus using a local oscillator and a serial potentiometer.
Raspberry Pi four was welcomed by the Pi enthusiasts for the increased processing power. However, this came at a price. The Pi 4 can draw up to 3 Amps, which means it has to dissipate 15 watts of power. Raspberry Pi cooling is a must.
From the simplest passive heat sink, through elaborate fan blowers and even to an exotic water-cooled idea, many options are available.
While lacking no imagination, all have a common denominator: it is almost impossible to plug an add on card into the GPIO expansion header.
THE SMART FANThe most elegant, compact and inexpensive cooling solution for your Raspberry Pi.
The Smart Fan has the form factor of the Raspberry Pi HAT. Its own tinny 32 bit processor receives commands from Raspberry Pi through the I2C interface. A step-up power supply converts the 5 Volts provided by Raspberry Pi to 12 Volts, ensuring precise speed control. Using pulse width modulation, it powers the fan just enough to maintain a constant temperature of the Raspberry Pi processor.
The Smart Fan preserves all the GPIO pins, allowing any number of cards to be stacked on top of Raspberry Pi. If another add-on card has to dissipate power, a secondary Smart Fan can be added to the stack.
Together with multiple add-on cards, the Smart Fan can be installed on the DIN-Rail, for sturdy industrial applications.
Stack Level Jumper
Two Smart Fans can be installed on top of each Raspberry Pi. The assumption is that you have one more card in the stack which requires cooling. The bottom side of the Smart Fan has a jumper which needs to be installed on the second fan, in order for the Raspberry Pi to differentiate the two I2C addresses.
SOFTWAREThe Smart Fan can be controlled from any program using simple command line or Python functions. A Node-Red interface let's you set and monitor the temperature from the browser. The software can maintain the temperature history in a log file which can be plotted in Excel, an example loop can be found HERE.
CONTROLLING THE FAN SPEED
Since the Smart Fan is slave to the I2C interface, Raspberry Pi must tell it what to do. Command line and Python functions are available to control the fan speed. Raspberry Pi needs to monitor the processor temperature and control the fan speed accordingly. A PID loop sample program can be downloaded from GitHub. In case of malfunction, if the temperature exceeds a safe limit, Raspberry Pi must shut itself off to prevent burnout.
The Smart Fan has a LED controlled by the local processor. At power up, the processor powers up the fan for 1 second, so the user can make sure the system is functional. The on board LED shows the status of the fan. When the fan is off, the LED blinks 1 time per second. When the fan is turned on, the LED blinks between 2 to 10 times per second, proportional with the speed of the fan.
Since the fan can be installed either on the top or on the bottom of the card, it comes unassembled. If you plan to use the Smart Fan to cool the Raspberry Pi, we recommend to install it on the bottom. To cool any other add-on card, install it on the top. All mounting hardware for installing the fan on the card, and the card on Raspberry Pi, is included.
When you purchase the Smart Fan Kit you will receive the following items:
1. SMART FAN HAT
2. 40x40x10mm Fan with mounting screws
3. Mounting hardware
Plug your SMART-FAN card on top of your Raspberry Pi and power up the system.
Enable I2C communication on Raspberry Pi using raspi-config.
Install the Smart Fan software from github.com:
- ~$ git clone https://github.com/SequentMicrosystems/SmartFan-rpi.git
- ~$ cd /home/pi/SmartFan-rpi
- ~/SmartFan-rpi$ sudo make install
- ~/SmartFan-rpi$ fan
The program will respond with a list of available commands.
The last release of the Smart Fan is missing the slot cutout for the camera. This has been a factory mishap which we missed on the prototype run. Everything else is functional.
SMART FAN IN THE NEWS
Being a Raspberry Pi novice, I like to try new things. I recently installed Ubuntu 20.10 on my RPi4 8GB system which has the SmartFan-rpi installed. I installed all software and initialized the i2c communication. Multiple errors appeared and the SmartFan would not run. I immediately contacted Sequent Microsystems support. They very quickly identified my problem - this novice had not installed "all the necessary" support files.
Once I followed their instructions, the SmartFan immediately came to life and is working wonderfully keeping my system cool. This is a most effective active cooling system! Thanks Sequent Microsystems for an excellent product and follow-on support!
The flexibility of putting the fan on either side is nice, but...the cable is insanely long. Who wants to do cable management for their fan? But as annoying as that is, the real kicker is the header pin length forces a minimum 19mm spacing between boards. The standoffs supplied are 18mm. The pins should have matched or they should have supplied 20mm standoffs (18mm and 20mm are commonly available).
I bought two of these, as well as a Chinese/eBay knock-off. The knock-off actually allows a 14mm spacing, both above and below the board when stacking. The knock has the fan permanently attached on the underside, no cable to worry about. It has some silliness like RGB lights and a detachable LCD display for temperature (never going to use that)
I think Sequent needs to make a version 2 (version 3?) to tighten up the spacing and supply matching standoffs. Maybe attach the fan permanently or shorten that cable.
Functionally, no complaints. It does what it's supposed to in cooling the pi and it lets me put another HAT on top.
Good point. In the latest revision the cable was shortened to the minimum requirement. Thank you for the feedback.
A great website and products.