02-20-2021, 05:12 PM
I would like to use an ultra-quiet low-power 12V 4-pin PWM fan and am trying to figure out how to best interface with the PWM signal and RPM Speed signals wires of such a fan. The specific fan I'm looking to use is the Noctua NF-A8 PWM fan which has the following electrical interface:
Blue: PWM Signal (+5V)
Green: RPM Speed Signal (open collector output)
Yellow: +12V
Black: Ground
I would need to ensure (somehow) that the FAN+ is always at 12V, I'm not sure how this pin gets controlled in startup via u-boot / Linux but in my application I would want to ensure it goes high and stays high sometime during boot.
I'm looking for options on how to interface to the Blue and Green cables. I think my options are either somehow directly to some of the 5V pins on the Pi-2 header, or alternatively, perhaps some sort of separate fan control breakout.
One idea I had was to use the Adafruit EMC2101 I2C PC Fan Controller and Temperature Sensor breakout. This would use the i2c interface on the pi-2 header.
I would then need to interface that with a temperature diode somewhere -- ideally one that already exists on the RK3399, the board near the SoC, or I guess on the CPU heatsink. From what I can tell, one of the 3904 BJT type diodes mentioned in Table 4 would work.
Does anybody have any experience using a 4-pin fan on the RK3399 in a NAS application?
Details on the Noctua fan interface.
Details on the EMC2101.
Blue: PWM Signal (+5V)
Green: RPM Speed Signal (open collector output)
Yellow: +12V
Black: Ground
I would need to ensure (somehow) that the FAN+ is always at 12V, I'm not sure how this pin gets controlled in startup via u-boot / Linux but in my application I would want to ensure it goes high and stays high sometime during boot.
I'm looking for options on how to interface to the Blue and Green cables. I think my options are either somehow directly to some of the 5V pins on the Pi-2 header, or alternatively, perhaps some sort of separate fan control breakout.
One idea I had was to use the Adafruit EMC2101 I2C PC Fan Controller and Temperature Sensor breakout. This would use the i2c interface on the pi-2 header.
I would then need to interface that with a temperature diode somewhere -- ideally one that already exists on the RK3399, the board near the SoC, or I guess on the CPU heatsink. From what I can tell, one of the 3904 BJT type diodes mentioned in Table 4 would work.
Does anybody have any experience using a 4-pin fan on the RK3399 in a NAS application?
Details on the Noctua fan interface.
Details on the EMC2101.