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.
Thursday, September 4, 2025
Mini-Split Line Cover Problems
Friday, August 15, 2025
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.
Wednesday, May 21, 2025
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.
Wednesday, May 7, 2025
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!?!?
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.
Monday, May 5, 2025
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.
Monday, March 31, 2025
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.
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.
Friday, March 14, 2025
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.
Saturday, March 8, 2025
ESP32 HUB75 DMA Hue Value Spectrum demo
Aurora Demo on ESP32 with a 16S 32x32 LED panel
Thursday, February 13, 2025
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;
Sunday, February 9, 2025
Testing LED panels for bad LED's
I have written two programs to test LED panels after someone sold me a pile of them with many bad LED's. Some panels had over 30 LED's that were not working. He also shipped them with no padding between the LED's! This resulted in smashed LED's and some of the alignment nubs were broken off. Fortunatly with some soldering I was able to reduce the number of bad LED's to 3 or 4 per panel. Now I can use them for testing out programs and configurations. Some LED's had broken runs but most of them just needed to be resoldered.
The first program tests the colors and leaves the panel white for quickly testing if the LED's just soldered are working. This does not work on 16S panels for some reason.
// RGBcolors test for Adafruit RGBmatrixPanel library.
// For testeing LED arrays for bad bits.
#include <RGBmatrixPanel.h>
#define CLK 8 // USE THIS ON ARDUINO UNO, ADAFRUIT METRO M0, etc.
#define OE 9
#define LAT 10
#define A A0
#define B A1
#define C A2
#define D A3
// Does not work with 16S panels if you add "D" nothing happens!
RGBmatrixPanel matrix(A, B, C, CLK, LAT, OE, false);
void setup() {
matrix.begin();
// fill the screen with colors
matrix.fillRect(0, 0, 32, 32, matrix.Color333(0, 7, 0));
delay(1000);
matrix.fillRect(0, 0, 32, 32, matrix.Color333(7, 0, 0));
delay(1000);
matrix.fillRect(0, 0, 32, 32, matrix.Color333(0, 0, 7));
delay(1000);
matrix.fillRect(0, 0, 32, 32, matrix.Color333(7, 7, 7));
delay(1000);
}
void loop() {
}
The next program is for sorting LED panels by how they are internally wired. There are 16S, 8S (There are many varieties of 8S) and 4S panels. It scans all LED's one at a time.
I could not get this to work with the normal drivers so I wrote my own using "bit banging". Its slow but works great! Note:This program was improved in March of 2021, it runs much better now!
// RGB bitbang test bits by scanning
#define CLK 8
#define OE 9
#define LAT 10
#define A A0
#define B A1
#define C A2
#define D A3
#define R1 2
#define G1 3
#define BL1 4
#define R2 5
#define G2 6
#define B2 7
int tbit;
int row;
int col;
void setup() {
pinMode(A, OUTPUT);
pinMode(B, OUTPUT);
pinMode(C, OUTPUT);
pinMode(D, OUTPUT);
pinMode(CLK, OUTPUT);
pinMode(OE, OUTPUT);
pinMode(LAT, OUTPUT);
pinMode(R1, OUTPUT);
pinMode(G1, OUTPUT);
pinMode(BL1, OUTPUT);
pinMode(R2, OUTPUT);
pinMode(G2, OUTPUT);
pinMode(B2, OUTPUT);
}
void loop() {
// Set sequential bits
for (row=0; row<16; row++){
for (col=0; col<64; col++){
for (tbit=0; tbit<64; tbit++){
digitalWrite(R1, LOW);
digitalWrite(G1, LOW);
digitalWrite(BL1, LOW);
if (tbit <= col){
digitalWrite(R1, HIGH);
// digitalWrite(G1, HIGH);
// digitalWrite(BL1, HIGH);
}
digitalWrite(CLK, HIGH);
digitalWrite(CLK, LOW); //Clock data in
}
// latch and display results
digitalWrite(OE, HIGH); // disable output while latching data.
digitalWrite(LAT, HIGH);
// select next column if it has changed
digitalWrite(A, LOW);
digitalWrite(B, LOW);
digitalWrite(C, LOW);
digitalWrite(D, LOW);
// update row selection
if ((row & 0x0001)>0)digitalWrite(A, HIGH);
if ((row & 0x0002)>0)digitalWrite(B, HIGH);
if ((row & 0x0004)>0)digitalWrite(C, HIGH);
if ((row & 0x0008)>0)digitalWrite(D, HIGH);
// delay(5); // dim display
digitalWrite(LAT, LOW);
digitalWrite(OE, LOW);
delay(50);
}
}
}
Sunday, February 2, 2025
Explaining the different types of LED Arrays
Not all LED arrays are the same, there are many varieties within a set size and set amount of LED's. There are the P numbers. P10 means 10mm LED spacing. P6 is 6mm spacing. P3 is 3mm spacing.
Then there are the S or scan or row select numbers. Typical S numbers are S4, S8, and S16. But they even vary within these numbers! Lets start with a 16S arrangement. In a 32 by 32 LED array there are two 32 bit shift registers one for the top half and one for the bottom (As well as one for each color). Then there are 16 row selectors that select what two rows are currently lit up.
Tuesday, January 28, 2025
Big LED sign with 6x4 of 32x32 P6 LED panels
Wednesday, January 1, 2025
Expanding my sign with 16x16 addressable LED arrays.
I am expanding my sign with 16x16 WS2812B Addressable LED arrays. Currently I am at 3x5 of these arrays but am working on adding three more for a 3x6 or 48 by 96 sign.
This is the built in demo with a T8000 controller. I had more luck with the SP801E controller.
Here I am starting to add the grids to make the pixels square. The grids are on thingiverse. I drilled too many holes in the luan because I confused the orientation. They need to connet from top to bottom.
This is another picture of assembling the arrays. I am using E-6000 glue to hold them in place. I glue two or three at a time just in the corners then put something on them to hold them in place till the glue dries.
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https://www.youtube.com/watch?v=STn5s0Ipr-M
This is a demo with an SP801E controller
https://www.youtube.com/shorts/VzCqLekaI-U
Here it is with WLED on an ESP32 processor
Here are some pictures from the WLED demo.