Add detailed power consumption measures

docs/hardware.md

@@ -6,7 +6,6 @@
 ### A388 System-On-Chip
 ![!Block Diagram](/img/hardware/soc_block_diagram.png)
 
-
 ## Connector / Interface List
 
 ![!Board Legend](/img/hardware/board_legend.jpg)
@@ -77,6 +76,34 @@ Helios4 board exposes on header J9 the SoC I2C Bus 1. Below is the header pin-ou
 
 ![I2C Pinout](/img/hardware/i2c_pinout.png)
 
+## Power Consumption
+
+**Board only**
+
+* Idle  : 3.6 Watts
+* Active : 5.6 Watts
+
+**Full Kit (with 4x HDDs)**
+
+| State               | AC calculated<br>power consumption | DC measured<br>power consumption | Remarks             |
+|---------------------|----------------------|----------------------|---------------------|
+|  Idle               | 19.3 W               | 16.8 W               |                     |
+|  HDD Read Access    | 27.4 W               | 22.8 W               |                     |
+|  HDD Write Access   | 30.3 W               | 25.2 W               |                     |
+|  Standby            | 8.0 W                | 6.7 W                | HDD in Standby mode |
+|  Suspend-to-Ram     | 7.2 W                | 6.0 W                | HDD in Standby mode |
+
+!!! note
+    Measures were done using a Current Clamp Meter on the Helios4 12V DC input. AC Power consumption is calculated based on a AC/DC conversion efficiency of 85%.
+
+    * Meter tool : Extech 380942 - 30A True RMS AC/DC Mini Clamp
+    * AC/DC Adapter : yczx1268 (efficiency : 85%)
+    * AC Input Voltage: 220V
+    * HDD: 4x WD Red 2TB (WD20EFRX) configured as RAID10
+    * Network : Connected at 1000Mb/s
+    * OS: ARMBIAN 5.73 stable Debian GNU/Linux 9 (stretch) 4.14.98-mvebu   
+
+
 ## HDD Recommendation List
 
 We recommend HDD which are designed for NAS (Network Attached Storage). Those NAS HDD are specially conceived for reliable 24/7 operation and offers lower power consumption and dissipation, less vibration and noise, and finally better warranty. We recommend the following models :

docs/wol.md

@@ -165,16 +165,14 @@ Measured using Sonoff POW R2 on AC side
 
 | Power state   | Power (Watt)  | Current (Ampere) | Remarks |
 |---------------|---------------|------------------|---------|
-|  Idle         | 16.18 - 19.87 | 0.14 - 0.17      | |
+|  Idle         | 19.87 				| 0.17						 |				 |
-|  Standby      |  8.24 -  8.63 | 0.09 - 0.10      | |
+|  Standby      |  8.63				  | 0.10      			 | HDD in Standby mode |
-|  Suspend      |  7.46 -  7.71 | 0.07 - 0.08      | |
+|  Suspend      |  7.71				  | 0.08      			 | HDD in Standby mode |
-| Halt/Shutdown | 11.95         | 0.11             | HDDs still active, fans run on full speed |
 
 !!! note
     * Nominal Input Voltage: 220V
     * HDD: 4x WD Red 2TB (WD20EFRX)
     * [I2C OLED screen](/i2c/) attached to the systems
-    * Variation of power consumption sometimes due to fluctuation of the input voltage
 
 ## Issues
 
@@ -190,4 +188,4 @@ Therefore it is advised to always enable WOL (**sudo ethtool -s eth0 wol g**) be
 
 When system is put in suspend mode, the PWM feature controlling the fan speed is stopped. The fans will either spin at their lowest speed ([Batch 1 fan](/pwm/#old-fan-batch-1)) or stop spinning ([Batch 2 fan](/pwm/#new-fan-batch-2)). In the latest case, while this is not an issue for the SoC itself which is designed to run with passive cooling, it might have a negative impact on the HDD peripherals because the ambient temperature inside the case will rise.
 
-Therefore it is advised to ensure that when system is suspended the case ambient temperature will not exceed the operating temperature your HDDs are rated for.
+**Therefore it is advised to ensure that when system is suspended the case ambient temperature will not exceed the operating temperature your HDDs are rated for.**