diff --git a/docs/helios64/fan.md b/docs/helios64/fan.md deleted file mode 100644 index d0557ec..0000000 --- a/docs/helios64/fan.md +++ /dev/null @@ -1,28 +0,0 @@ -## PWM Introduction - -Please kindly review the [pwm pages](/helios4/pwm) from the Helios4 device. -Basically the PWM mechanism of Helios64 board is same with Helios4. - -## Fan Control Schematic - -![!Fan Control Schematic](img/fan/fan_control_schematic.png) - -**Remarks** - -| Description | Header P7 | Header P6 | Remarks | -|-----------|---------|-----------|---------| -| PWM pin | PWM0 | PWM1 | 5V tolerant | -| SENSE pin | GPIO4_C5 | GPIO4_C7 | no kernel module/userspace apps that make use of this pin yet | -| PWM Frequency | 25 kHz | 25 kHz | defined in device tree | - -## Fan Specification in Helios64 - -Coming Soon. - -## Use Case in Linux - -Coming Soon. - -!!! Notes - RPM readings in the PWM fans is not available in Helios64 board. - diff --git a/docs/helios64/img/pwm/fan_connector.png b/docs/helios64/img/pwm/fan_connector.png new file mode 100644 index 0000000..00990ed Binary files /dev/null and b/docs/helios64/img/pwm/fan_connector.png differ diff --git a/docs/helios64/img/fan/fan_control_schematic.png b/docs/helios64/img/pwm/fan_control_schematic.png similarity index 100% rename from docs/helios64/img/fan/fan_control_schematic.png rename to docs/helios64/img/pwm/fan_control_schematic.png diff --git a/docs/helios64/img/pwm/fan_type_a_curve.jpg b/docs/helios64/img/pwm/fan_type_a_curve.jpg new file mode 100644 index 0000000..b8baa00 Binary files /dev/null and b/docs/helios64/img/pwm/fan_type_a_curve.jpg differ diff --git a/docs/helios64/img/pwm/fan_type_b_curve.jpg b/docs/helios64/img/pwm/fan_type_b_curve.jpg new file mode 100644 index 0000000..89cbf68 Binary files /dev/null and b/docs/helios64/img/pwm/fan_type_b_curve.jpg differ diff --git a/docs/helios64/img/pwm/fan_type_c_curve.jpg b/docs/helios64/img/pwm/fan_type_c_curve.jpg new file mode 100644 index 0000000..c542b8e Binary files /dev/null and b/docs/helios64/img/pwm/fan_type_c_curve.jpg differ diff --git a/docs/helios64/img/pwm/pwm_duty_cycle_graph.png b/docs/helios64/img/pwm/pwm_duty_cycle_graph.png new file mode 100644 index 0000000..c53ea8b Binary files /dev/null and b/docs/helios64/img/pwm/pwm_duty_cycle_graph.png differ diff --git a/docs/helios64/pwm.md b/docs/helios64/pwm.md new file mode 100644 index 0000000..7e101b3 --- /dev/null +++ b/docs/helios64/pwm.md @@ -0,0 +1,47 @@ +## PWM Introduction + +PWM, or pulse width modulation is a technique which allows us to adjust the average value of the voltage that’s going to the electronic device by varying duty cycle of the power at a fast rate. + +The term *duty cycle* describes the proportion of 'on' time to the regular interval or 'period' of time; a low duty cycle corresponds to low power, because the power is off for most of the time. Duty cycle is expressed in percent, 100% being fully on. When a digital signal is on half of the time and off the other half of the time, the digital signal has a duty cycle of 50% and resembles a "square" wave. When a digital signal spends more time in the on state than the off state, it has a duty cycle of >50%. When a digital signal spends more time in the off state than the on state, it has a duty cycle of <50%. Here is a pictorial that illustrates these three scenarios: + +![PWM duty cycle](/helios64/img/pwm/pwm_duty_cycle_graph.png) + +## PWM Fan Implementation + +### Type-A + +![Type A Curve](/helios64/img/pwm/fan_type_a_curve.jpg) + +### Type-B + +![Type B Curve](/helios64/img/pwm/fan_type_b_curve.jpg) + +### Type-C + +![Type C Curve](/helios64/img/pwm/fan_type_c_curve.jpg) + + +## PWM Fan Schematic + +![!Fan Control Schematic](img/pwm/fan_control_schematic.png) + +**Remarks** + +| Description | Header P7 | Header P6 | Remarks | +|-----------|---------|-----------|---------| +| PWM pin | PWM0 | PWM1 | 5V tolerant | +| SENSE pin | GPIO4_C5 | GPIO4_C7 | no kernel module/userspace apps that make use of this pin yet | +| PWM Frequency | 25 kHz | 25 kHz | defined in device tree | + +## PWM Fan Connector + +![Fan Connector](/helios4/img/pwm/fan_connector.png) + +Connector Pinout + +| Pin | Function | Wire Color | +|-----|----------|------------| +| 1 | GND | Black | +| 2 | 12V | Red | +| 3 | Sense | Yellow | +| 4 | Control | Blue | diff --git a/mkdocs.yml b/mkdocs.yml index 1130d33..7f091ab 100644 --- a/mkdocs.yml +++ b/mkdocs.yml @@ -79,7 +79,7 @@ nav: - Jumper: 'helios64/jumper.md' - LED : 'helios64/led.md' - M.2 : 'helios64/m2.md' - - PWM Fan : 'helios64/fan.md' + - PWM Fan : 'helios64/pwm.md' - RTC : 'helios64/rtc.md' - SATA : 'helios64/sata.md' - SPI : 'helios64/spi.md'