Smart Fan HAT the Best Cooling Solution for Raspberry Pi

FEATURES 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 Works with any Raspberry Pi from ZERO to 5 ECCN Code EAR99 (Ver. 6.0 uses also GPIO 12) Super quiet and efficient. Command Line Interface Python Library Python Example Node-RED node Home Assistant Integration DESCRIPTION A must for all mission critical installations Due to semiconductor shortages, the current version of the 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 FAN HAT The most elegant, compact and inexpensive cooling solution for your Raspberry Pi. The card 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 card 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 Fan can be added to the stack. DIN-RAIL MOUNTING Together with multiple add-on cards, the Fan can be installed on the DIN-Rail, for sturdy industrial applications. Stack Level Jumper Two HATs 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 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. DOWNLOADS SMART FAN DOWNLOADS SOFTWARE The 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 HAT 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. SELF TEST The 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. YOUR KIT 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 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 Kit you will receive the following items: 1. SMART FAN HAT 2. 40x40x10mm Fan with mounting screws 3. Mounting hardware QUICK START 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 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. ERRATA The last release of the 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 This Raspberry Pi Smart Fan HAT is Stackable and GPIO Friendly Raspberry Pi Smart Fan cooler hits Kickstarter Smart Fan HAT cools the Pi and passes the GPIO Sequent Microsystems Opens Funding for the Smart Fan, a Clever Cooling Card for the Raspberry Pi Raspberry Pi Smart Fan cooler hits Kickstarter