doc: add hardware test

README.md

@@ -18,17 +18,83 @@ It allows to:
 usage
 =====
 
-flashing
---------
+status
+------
 
-There are several ways to flash the board (from easiest to more development friendly):
+On the RJ45 ports there are 4 LEDs.
+These indicate the status:
 
-- connect USB to serial adapter TX and RX signals on the DEBUG port. Short DL to GND pin while powering up to enter download mode
-- populate DL and RST buttons to not have to short the pins by hand
-- connect USB to serial adapter RTS to RST and DTR to DL on the DEBUG port, to switch to download mode from the computer
-- populate the USB-C port and CH340K USB to serial adapter to avoid using and external adapter
+- the center-right LED indicates the >6V status: it is on when 6-60V power is provided to the board
+- the rightmost LED indicates the 5V status: it is on when the on-board DC-DC voltage regulator converts the 6-60V to 5V right after 6-60V is plugged in, or when 5V power is provided externally
+- the center-left LED indicates the DMX RX traffic: it blink on DMX input traffic (when the board is configure as slave)
+- the leftmost LED indicates the DMX TX traffic: it blinks on DMX output traffic (when the board is configure as master)
+
+hardware test
+-------------
+
+You got the WLED chain board manufactured.
+It is not time to test if the hardware has been assembled correctly.
+
+Test the 6-60V power input for shorts:
+
+- use a multimeter in resistance mode
+- put the COM lead on the 6-60V screw terminal - terminal
+- put the V lead on the 6-60V screw terminal + terminal
+- the multimeter should read O.L or above 10 MOhn
+- put the COM lead on the 6-60V screw terminal + terminal
+- put the V lead on the 6-60V screw terminal - terminal
+- the multimeter should a fluctuation resistance above 100 kOhm
+
+Test the 5V power port for shorts:
+
+- use a multimeter in resistance mode
+- put the COM lead on the 5V screw terminal - terminal
+- put the V lead on the 5V screw terminal + terminal
+- the multimeter should read 1.8 kOhm
+- put the COM lead on the 5V screw terminal + terminal
+- put the V lead on the 5V screw terminal - terminal
+- the multimeter should an increasing resistance above 1 kOhm
+
+Test the 3.3V rail for shorts:
+
+- use a multimeter in resistance mode
+- put the COM lead on the I/O header 3V pin
+- put the V lead on the I/O header 0V pin
+- the multimeter should read 3-4 kOhm
+- put the COM lead on the I/O header 0V pin
+- put the V lead on the I/O header 3V pin
+- the multimeter should above 10 kOhm
+
+Test the 3.3V voltage regulator:
+
+- connect a power supply set to 5V and limited to 0.2 A on the 5V screw terminal
+- the rightmost green LED should be on
+- the board should draw around 0.1A
+- ensure 3.3V are present on the I/O header 3V/0V pins
+
+Test the USB power input:
+
+- plug a USB cable connected to a USB port supply on the USB-C port
+- the rightmost green LED should be on
+- the board should draw around 0.1A
+- ensure 3.3V are present on the I/O header 3V/0V pins
+
+Test the 5V voltage regulator:
+
+- connect a power supply set to 6V and limited to 0.3 A (must be more than 0.2 A) on the 6-60V screw terminal
+- the rightmost green and second rightmost yellow LEDs should be on
+- the board should draw around 0.1A
+- ensure 5.0A are present on the 5V screw terminal
+
+Test resettable 1.8A input fuse:
+
+- connect a power supply set to 7V and limited to 3A on the 6-60V screw terminal
+- the rightmost green and second rightmost yellow LEDs should be on
+- connect a 1 Ohm resistor across the 5V screw terminal
+- after 10 to 20 seconds, the green light should turn off while the yellow light remains
+- remove the resistor from the 5V screw terminal
+- after a second, the green light should turns back on
 
-Once in download mode, we can flash the [WLED firmware](https://github.com/Aircoookie/WLED/releases) using the [web interface](https://install.wled.me/), or [esptool](https://github.com/espressif/esptool):
 
 ~~~
 wget https://install.wled.me/bin/release_0_14_0/esp32_bootloader_v4.bin