kingkevin
/
board
1
0
Fork 0
Code Issues Pull Requests Projects Releases 37 Wiki Activity

doc: add v1 changes, mostly related to power

This commit is contained in:
King Kévin 2023-10-07 06:26:39 +02:00
parent c400aac26b
commit 027d1118a1
2 changed files with 37 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
CHANGELOG.md
View File

@ -1,3 +1,11 @@
v1
--
- use screw terminal for power input/output to support more current
- add power input protection: PPTC and reverse polarity
- add switch configure DMX512 line termination
- change DC-DC buck converter for large input voltage
v0
--

45
README.md
View File

@ -6,7 +6,7 @@ purpose
The [WLED](https://kno.wled.ge/) firmware is ideal do control addressable LEDs strip.
WLED chain is a hardware board for it, matching my usage: robust remotely controlled LED strip based light installations for festivals.
It allows to:
- use of the shelf 12-24V power supplies to power the 5V LED strips
- use of the shelf 12-48V power supplies to power the 5V LED strips
- inter-connect them to form long chains (only connecting the first to externally provided power and data)
- use cheap Ethernet CAT5E cables to inter-connect them (also over long distances)
- provide power and data over the Ethernet cables
@ -34,12 +34,25 @@ This means you can power up to 5 m of WS2812b 30 LEDs/m strip at full brightness
For more LEDs, limit the brightness in WLED, or use multiple boards and chain them.
The spring loaded terminals are only rated for 2A, with a maximum wire size of AWG 20.
If you intend to draw more current, you can add a connection to another 5V output from the LEDs or power port.
If you intend to draw more current, you can add a connection to another 5V output from the LEDs port or the 5V screw terminal (can handle up to 5V).
This is particularly relevant for re-injecting power, which you should do minimum every 5 meters.
If you need even more current, or use thicker cables, just solder the cable directly to the pins on the bottom or on the rear tab of the barrel jack connector.
If you need more than 5A, you are exceeding the use case of this board.
Switch back to using a external power supply and connect the LED strips directly to it.
You can even power the board with the same 5V or 8-36V power supply using the power port.
Switch back to using an external power supply and connect the LED strips directly to it.
You can even power the board with the same 5V or 8-60V power supply using the DC jack or screw terminals.
The 8-60V power input allows using any kind of power supply, like common 12V, 24V, or 48V.
But is also allows using 48V LiPo batteries (going up to 55V), to operate them without grid power.
There is an over current input protection of 2A using an PPTC.
This is to protect the board from very bad accidents, and because Ethernet cables are no meant to carry power (PoE limit is 960 mA per pair, we are using two).
To be able to power multiple WLED chains, each drawing 25W, use higher voltages (48V up to 60).
If you are using 12V or 24V LED strip (e.g. not 5V), you can use the screw terminal to re-use the corresponding 8-60V output.
This is not fused.
But if your are using Ethernet cables, you still should not exceed the 2A limits.
And if you are using these higher voltage LED strips, you probably are building bigger light installation, and should take can of the power supply separately instead of relying on the WLED chain.
Then you can also use this power supply to power the WLED chain board using the 8-60V port, but only one of them in the whole chain (else the multiple power supplies might interfere with each other).
The 8-60V input is also reverse polarity protected, after the fuse.
The 5V rail input/outputs are not fuse or reverse polarity protected.
features
--------
@ -58,14 +71,13 @@ Features already implemented:
- in-line LED data resistors for [signal conditioning](https://quinled.info/data-signal-cable-conditioning/). Ideally it should use a smaller value since it's intended for running the signal along ground over short distances, but there were already 100 Ohm on the board for DMX512 termination, and it allows better compatibility for longer single ended cables.
- external WiFi antenna port, by using the I variant of the ESP32-S2-WROOM, with appropriate connector
- PCB fitting in [sonoff waterproof enclosure](https://www.sonoffegypt.com/products/sonoff-ip66-waterproof-case)
- high voltage input (up to 60V, using TPS54560DDAR)
- input protection (reverse polarity, PPTC)
Features that might get implemented:
- microphone/line in for sound reactive (use [ESP32-LyraT-Mini](https://docs.espressif.com/projects/esp-adf/en/latest/design-guide/dev-boards/board-esp32-lyrat-mini-v1.2.html) design as reference)
- RDM support (mostly software support)
- automotive fuse protection (input or output protection)
- high voltage input (up to 60V, using TPS54560DDAR)
- input protection (reverse polarity, PPTC)
Features will not be implemented:
@ -74,6 +86,7 @@ Features will not be implemented:
- USB Power Delivery: this is just a convenience feature, but using expensive lower power USB chargers is not ideal for the intended usage (festival installation)
- Lithium battery input and charger: it does not fit the intended usage, with large external power supplies providing enough power for power hungry LED strips. Small batteries would not be able to handle that over longer time. You can still use the 5V power input though, and charge the battery separately
- Power over Ethernet (active): I do use passive Power over Ethernet, by providing power on 2 pairs of the Ethernet cable that are not used for 10/100 Mbps communication. This allows using very simple and inexpensive injectors to power power, using and power supply. Active PoE require specials and more expensive injectors or power supplies, and complex extractors in each device. This is a to hard requirement. Feel free to use PoE though. There are plenty of relatively cheap injectors and extractors that you can use as external devices next to the boards.
- automotive fuse protection (input or output protection): there is not enough space to place such large fuses. We already have one input protection (fuse + reverse polarity on 8-60V), so you just have pay attention to the 5V outputs (limited to 5A by the DC-DC converter) or input (supported, but not the intended use).
background
==========
@ -132,31 +145,31 @@ intended use case
The purpose is to provide a simple board able to control LEDs strips.
It should be better than general purpose development boards.
A built-in voltage converter allows driving an LED strip.
It is intended for small installations, not requiring more than 5 meters of LED strings.
A built-in voltage converter allows driving an LED strip using regular external power supplies.
It is intended for small installations, not requiring more than 5 meters of LED strings per device.
This keeps the power supply small.
The board is not intended for large LED installation requiring a lot of power.
The board should be cheap enough to be a default choice when creating a small LED installation.
the goal is at 5 to 10€ per board.
This prevents me for using Ethernet, since the PHY and magnetics are expensive (~ 3€).
The goal is under 10€ per board.
This prevents me for using Ethernet network, since the PHY and magnetics are expensive (~ 3€).
It should not require a complex installation.
Something like a LAN requiring a permanent switch or router is already too much.
The board should be able to work on its own.
It should be make it easy to create multi-device installations.
It should make it easy to create multi-device installations.
This is provided by the chaining capability.
You can connect one device to another, and the job is done.
This single link provides power.
This allows using a single power supply for the whole installation, just connected to the first device in the chain.
This allows using a single power supply for the whole installation, just connected to one device in the chain.
It should use cheap and common cable for the chain link, such as Ethernet cables.
It should accept common off the shelves power supplies, such as 12-24V 2-4A bricks.
The chain link should also allow synchronising the devices.
The chain link should also allow synchronising the devices, without requiring a network connection.
Ideally it should also provide an interface to reliably remotely control them.
Thus the DMX512 protocol.
For that it uses the DMX512 protocol.
features
--------