Build Your Own LED Wall

I have been building my own LED walls.  So far I have two of them, one uses P4 indoor Panels the other uses P5 indoor panels.  

All of the panels were purchased at huge discounts.  Here are some pictures of my eBay purchases for a total of 35 P4 panels.  You have been told that you cannot intermix LED panels.  I have used three different types of panels and a totally red, green or blue image shows that they are obviously not matched.  However, real images dont show up the mismatch nearly as much!

Most P6 panels can be connected together by metal brackets that have holes on 1 inch centers and are found at most hardware stores. P4 and P5 panels use 3D printed junctions and 3/4 by 3/4 aluminum rails for the outside edges.  I also have a mounting adapter for 5A-75B receiver cards that can control up to 8 strings of LED panels on thingiverse.

This is a schematic of a typical setup.  The 5A-75B can only control strings of 6 panels with the default lessings.

Here are two pictures of some assembled LED walls.  The second does not have the top and bottom aluminum rails installed and the vertical rails were moved to the middle of the panels so they would match the hanging loops spacing.

To keep the LED walls so that they are almost flat to the wall I use external power supplies.  Each power supply can run 15-20 LED panels.  I use 12 Gague speaker wires and 50 amp connectors to connect the power supplies to the panels.  I have soldered the power cables together or used binding posts to connect the power cables together.  The white plastic binding posts with holes that you insert the wires into seem to work the best.

Here is a picture of a P6 panel system with binding posts connecting the power lines together.  You can see that is is more dangerous than soldering the wires, and though matter how tight the screws are, somehow the wires will come loose.

The next pictures show the two types of binding posts, Regular and white with holes for the wires.

There are three different type of LED panels but did you notice that in the pictures above?  Here is red, green, blue and white test pictures. The blue makes the location of the three type obvious.  the red and green are harder to tell them apart.

Now the white picture has a different shade on the left side.  Why?  It was power supply overload!  The left side is using a different power supply.

Mini-Split Line Cover Problems

I have now installed three mini-split heat pumps.  I would only recommend the MrCool ones as the flared line sets seem to always leak. One of the issues is in covering the line sets.  Some people use the plastic eves, and I have done that as well on an existing HVAC installation. This one installation took two of the line cover kits at $39 each, and then I was still short one straight coupler.  So I designed my own couplers and 3D printed them.

Here is a picture of the first two couplers that I designed.  Later I came up with a design with hidden screws. I did not have white filament so I had to spray paint them to white.  My designs are on thingiverse.

 

I finally got a Zero Turn Mower a Z Force S 46

I bought my first Zero Turn Mower, its a Cub Cadet Z Force S 46 for $350.  Boy was I in for an education!  The mower only had power to one rear tire.  I decided to change the trabnsmission fluid but quickly discovered there is no drain hole!  So after watching many Youtube videos I decided to add my own drain holes.  I chose a 1/4-20 by 1/2 inch bolt, with a metal washer and a rubber washer to make it watertight.  I drilled a small hole then the hole size for the tap then tapped the holes.  Changing the fluid did not fix the problem!

After watching many more videos I decided to see it the lever was being pulled to tell the transmission to move.  It worked on one side but not the other.  I chased the issue to a broken plastic part costing about $16.

Now to fix the oil leak out of the overhead valve cover....

Here are some pictures of the ad on Facebook for this mower.  It was a real bargain!

How to repair LED matrix panels.

A few years ago I had two P3 LED panels with missing LED's in the corners due to being beaten up in shipping.  Recently it happened again, this time three P5 LED panels had missing LED's from shipping abuse.  In another case I bought 18 P6 panels that were likely bad before they were shipped.  Every panel had bad LED's, some had as many as 30 LED's that were not working out of the 1024 on the panels. At first I repaired them to where 1-5 LED's were still out, but then with a better soldering iron tip I was able to get them to 100% working.

I want to show you how to repair minor problems with LED matrix panels.  Usually it is a corner LED that is loose or missing.  You can buy reels of 100 LED's for about $6.  In the P3 and P5 panels they were 2121 LED's.  The P6 panels had 3535 LED's.

First remove the almost invisible screws near the missing LED.  Then lift the panel screen and make two small cuts in the screen as can be seen in the next picture.  Remove the cut out piece. Set the screen back down.  Clean up the solder pads, leave some solder on them.

Then slide in the new LED into place with the panel powered up so you can see if it is oriented correctly by it lighting up.  Then, while holding the LED down with a small screwdriver, solder the two visible pins into place.  Next, lift the screen and prop it up.  Solder the two pins that you cannot see by "feel".  Then test the screen to make sure that it is working now.

Signs, Signs, Everywhere Signs!

I have just finished my latest book "LED Sign Projects".  I am not happy with the cover.  Besides being off center its kind of redundant.  LOL.  Also they used to add a page saying it is a proof.  But if you were happy with it you could remove that page and sell it.  Now they have "Not for Resale" on the cover!  The proof costs about the same as buying one so why do that to it!?!?

Another cover picture was "Signs, SIgns Everywhere Signs" after the song from the 70's.  But it lacked contrast.  Most cameras do not take accurate pictures of LED signs.  Would this make a better cover image??

I just completed one of my biggest signs ever.  Its 5 feet wide and 3 feet tall, the equivalent of a 70" TV screen.  There are 30 of the 32 by 64 P5 LED panels for over 30,000 pixels.  The resulting image is awesome!  Unfortunatly the pictures did not turn out well.  

This picture was taken before I put the top and bottom aluminum rails on it.  I use Steel L brackets at the corners to reinforce them and the mounting eyelet goes into that steel L Bracket as well.  So most of the weight is carried by the vertical aluminum rails.  I use external power supplies that way it is almost flush to the wall when it is hung up.

Here are some of my other LED signs from the back side.  This is similar to the one shown above.  Note that the panel joiners are all 3D printed.  I tried 3D printing the edges but they broke too easily so I use 3/4 inch L aluminum extrusions found at most hardware stores.

This is a water resistant version featureing 4x5 or the 32x32 pixel P6 LED panels.

Using LED strips to light up a Street sign instead of fluorescent bulbs

A couple of years ago I replaced the non-working five foot fluorescent bulbs in our church street sign with LED's.  However the horizontal strips were visable and became annoying.  So I came up with the idea of using edge lighting.  The LED strips would be on a metal surface so they would be less likely to overheat and burn out.  

I had some 130 per Meter or 36 per foot 2835 SMD LED strips.  They were 10 Meters or 394 inches or 32.8 Feet in length.  They are soft white and run off 12 Volts.  The total power is 90 watts per 10 meters length.  I used two of these strips for four laps around the inside of the sign.  I think if I was to buy them I would get bright white LED's instead.

This is the results as seen at night.  No more horizontal strips of lights!  It does dim a little in the center but it sure looks better.  Now to get a bigger LED sign!

We had to dig up the church well

The pump quit in the church well so we had to dig it up.  When we tried to pull it we could see somthing on the pitless adapter.  We tapped it with a long stick and discovered it was a rock and now it was further down in the well.  No amount of pounding or pulling would loosen the pitless connector.  So we had to did up the well.

After digging up the pitless and removing it, the pump came up easily.  We did not see any rocks!?!  We did see the real problem: the wires to the pump were burnt and one wire was disconnected.

We could also see the pitless was bigger than normal and after hitting it many times with different hammers it finally came apart.  there was no O ring!  It had likely leaked and the leaked water formed a rust/calcium bond glueing it in place.

Waveshare Zero to Pi3 Review

I recently purchased a Waveshare Zero to Pi3 adapter.  I had a couple of Pi zero's laying around not being used because I had to look up the HDMI and USB adapters in order to use them.  One Zero was even so old that it did not have any built in network ability.  I had to use USB memory sticks to add programs to it.  

This next picture shows the Zero adapter in use.

I could not get it to fit my 3D printed case as it is a very tiny bit wider and the memory card jack is in the wrong place.  I might design a modified case with the new memory card position.  It did mount fine on a piece of plastic with the standard raspberry Pi hole spacing.

When I went to test it, the video worked but the USB jacks did not work.  Then I squeezed it a little more and the USB jacks moved a tiny bit and started working.  Even the network jack worked but, to be honest, the Zero is a model 1.3 and it is to slow for browsing online web sites.

The adapter is also missing the audio jack, but most of the time I have to disable audio to run my projects so that is not an issue for me.  Alltogether I love this little adapter as it brought back usefulness to my Zero's.  

I own a raspberry Pi model 1, 2, 3 and 4.  I was surprised whrn I discovered that I needed a HDMI adapter for the model 4!  Now if I can just keep from loosing it!

Mackie Thump TH-15A Powered speaker Repair

 I was asked to repair a Mackie Thump TH-15A Powered speaker by a friend.  It powered on and everything looked good but there was no sound coming out.  I checked the speakers and the power supplies but everything was just fine.  However, the computer board was getting really hot.  It had 3.3 volts coming into a voltage regulator but only .5 volts coming out.  I tried easter egging the capicitors and it turned out to be the tiny little .1 uF capacitor that was shorting out the power supply.  The correct output is 1.2 volts.

This is what the guts look like, we are going to zero in on the logic board.

This is the logic board once the metal cover is removed.

These are the filter caps on the 1.2 volt power supply circled in red.

This is what the powered speaker looks like once it was back together.

ESP32 HUB75 DMA Hue Value Spectrum demo

The Hue Value Spectrum demo is beautiful, cameras do not do it justice.

This is found at https://github.com/mrcodetastic/ESP32-HUB75-MatrixPanel-DMA

This software connects to just the input port of the LED array.

The issue with this software is that it it too fast.  The speed results in noise from the 3 volt logic driving the 5 volt panel.  You have to play with the ground wires and keep the ribbon cable as short as possible to prevent noise and even then there are faint blinking LED's from th noise issue.

Another issue is the software does not support "Strange" LED panels like most 8S outdoor panels.

Aurora Demo on ESP32 with a 16S 32x32 LED panel

This is the Aurora Demo working on 32x32 RGB LED matrix panel with an ESP32 Processor.  I bought a circuit bard to do this but could not get it to work, so I went with jumper wires and it worked almost perfectly from the start!

This wiring arrangement uses two sets of jumper wires going to both the input and output of the LED panel.  This makes it almost impossible to transfer it to another panel to test different ones to see if they are supported inthe software.

The wiring looks like this:

This wiring makes it difficult to add more panels or to try using another panel.

New Big LED sign powered by Raspberry Pi

I have made another big LED sign, but this time it is powered by a Raspberry Pi.  At first I used the Adafruit Hat ,but I have upgraded to the three HUB75 Hat from ElectroDragon! This enalbes three chains of LED arrays. So far I have 5 32x32 panels in each chain but I will likely expand that.

This is a view of the back of the assembled panel. I am using metal brackets to hold the panels together as they have on inch spacing. 24mm is ideal as the one inch spacing leaves about a two mm space between the panels. I have a 3D printed version of the brackets on thingiverse and have used them in other designs.

Here is a couple of pictures of the panel being lit up. The text demo is limited to one line of panels.

There are several demo programs to check out the proper operation of the Raspbery Pi adapter.

Here is a link to the video of the demos;

https://youtu.be/44ykJb_ZB7A?si=ylKY5zBix4FU4i2X