The O2 sensor did go back to spikeing after driving for a while but the check engine light is still off.
Friday, December 29, 2023
Blowby before+after treating with CRC and Seafoam.
The O2 sensor did go back to spikeing after driving for a while but the check engine light is still off.
Wednesday, December 20, 2023
Using LED's to replace the flourescent bulbs in a street sign
UPDATE: the 5630 LED's are burning out after only two months of operation!
I have been using LED strips to replace the flourescent bulbs in a street sign. My first attempts was to wrap the LED strips around the dead light bulbs. That did not work that well. My next attempt is to make a signboard and cover it with eight LED strips on each side.This will require 12 volts at 20 amps to run it! I switched the power to wire nuts and 12 volt 10 amp power supplies after this picture was taken. The barrel connectors in the picture got really hot.
This is the sign with the old LED strips wrapped around the bulbs.
Wireless Bridge CPE for a Link to another building
I just installed a wireless bridge for a link to another building. The distance was about 3/4 of a mile. The results were excellent! I had no knowledge of how to do this other than using repeaters to pick up internet from a house or two away. This time I needed to reach a building that was a few blocks away.
I used google maps to see if there was a straight shot between the locations. Then I went up on the roofs but could not see all the way to the other end from either direction. There was nothing visible in the way. It was a narrow shot as some pine trees surrounded my house but there was a gap in just the right direction.
I bought a model that has lots of LED's on the side to be able to troubleshoot any issues. I installed the "A" unit on the roof of my house. Then the "B" unit (You can change A to B with a switch) was installed on the building. I was amazed at the results the signal level was 100%! But there was no internet at the receiving end. The issue turned out to be that I had two internet cables at my house with a union in the middle and lost a connection somewhere. Switching to 100 foot exterior grade cables at both ends resolved that issue.
Here is the ad for the bridge on eBay:
This is the receiving unit. I made a PVC rooftop mounting bracket to hold it on the peak of a roof.
This is the transmitting unit on the roof of my house.
Thursday, December 14, 2023
Another amplifer rebuild with a TDA7394 Power Amplifier board
Once again I am rebuilding another amplifer this time with a TDA7394 Power Amplifier board. I picked up theis fried amplifier at a Hmfest from a friend for like $10 for the poweer transformer. I tested the output transistors and all but one were shorted. So I decided to rebuild it with a dual TDA7394 amplifier board for $22 on eBay. The power transformer is 60 VCT so the rectified power is + and - 42 volts DC. That is a little high for the IC but within its specs. It should deliver 100 watts per channel into 8 ohms without any problems.
Here is the old circuit board. The preamp seemed OK so I decided to try to save it.
So I cut the old circuit board in half with a hand saw.
Tuesday, November 28, 2023
Converting RGB controller to ESP8266 WLED Ws2812 Controller.
I am converting an old RGB controller to an ESP8266 WLED WS2812 Controller. I removed the power transistors and cut the runs for the pull up resistors (Just to the left of the large pads where the power transistors were). I tapped into the 5V buss at the top and the ground was available on a pin on the power transistors as marked in the picture. D1 D2 D3 go to the large solder pads where the power transistors were mountd. I should have used resistors for the D1-D3 lines.
Wednesday, November 1, 2023
MLX90640 and ESP32 Thermal Imaging Camera with 2.8" TFT SPI
I decided to update my old thermal imaging camera. Back in 2020 I had built a AMG8833 based camera. Its resolution was only 8x8 pixels. The MLX90640 is 32x24 pixels, that is a huge improvement for about $40. I was hoping that I could just unplug the one sensor and plug in the new one. Things are never that simple!
This is a picture of the completed project. The camera does not do a good job. I tried multiple cameras and they all fail to show the varying shades of colors! BTW that is me holding the camera.
I could not get the sparkfun MLX90640 library to load or run. That was desired to be able to use some software already available on the web. So I was stuck with the Adafruit library that was easily installed within the Arduino IDE. But I had to write my own interface for the LCD screen. Then I added the screen support to the simpletest program instead of sending the results to the serial port. Make sure you also install the ILI9341 driver within the Arduino IDE.
Connections:
LCD:
26=C/D
18=SCK
19=MISO
23=MOSI
5=CS0
3.3V=VCC,RES,LED (Jumpered on display)
GND=GND
MLX90640
22=SCL
21=SDA
3.3V=VIN
GND=GND
Here is my code:
#include <Adafruit_MLX90640.h>
#include "Adafruit_GFX.h"
#include "Adafruit_ILI9341.h"
#include "SPI.h"
#define PRINT_ASCIIART
// Use the default pins for all but:
#define TFT_CS 5
#define TFT_DC 26
Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC);
Adafruit_MLX90640 mlx;
float frame[32*24]; // buffer for full frame of temperatures
int r,g,b;
void setup() {
Serial.begin(115200);
delay(100);
if (! mlx.begin(MLX90640_I2CADDR_DEFAULT, &Wire)) {
Serial.println("MLX90640 not found!");
while (1) delay(10);
}
Serial.println("Found Adafruit MLX90640");
Serial.print("Serial number: ");
Serial.print(mlx.serialNumber[0], HEX);
Serial.print(mlx.serialNumber[1], HEX);
Serial.println(mlx.serialNumber[2], HEX);
mlx.setMode(MLX90640_CHESS);
mlx.setResolution(MLX90640_ADC_18BIT);
mlx.setRefreshRate(MLX90640_2_HZ);
// Screen setup
tft.begin();
tft.setRotation(3);
tft.fillScreen(ILI9341_BLACK);
tft.setTextSize(2);
}
void loop() {
if (mlx.getFrame(frame) != 0) {
Serial.println("Failed");
return; }
// determine the ranges
int maxt=0;
int mint=255;
for (uint8_t h = 0; h < 24; h++) {
for (uint8_t w = 0; w < 32; w++) {
int t = frame[h*32 + w];
if (t > maxt) maxt=t ;
if (t < mint) mint=t ;
}
}
tft.setCursor(0, 210);
tft.print("IR Camera Max Temp: ");
tft.fillRect(230, 210, 32, 16, ILI9341_BLACK );
tft.setCursor(230, 210);
tft.print(maxt);
// drawing the picture
for (uint8_t h = 0; h < 24; h++) {
for (uint8_t w = 0; w < 32; w++) {
int t = frame[h*32 + w];
r=0; g=0; b=0;
int t2= map(t, mint, maxt, 0, 255);
if (t2 > 70) r = t2+120;
if (r > 255) r=255;
if (t2 > 130) g = t2; // Highlight higher temps
if (t2 < 70) b = 255-t2; // More blue=colder
tft.fillRect(w * 8, h * 8, 8, 8, tft.color565(r, g, b));
}
}
}
Here are several views of the completed wiring if you need something to compare yours to.
Thursday, October 12, 2023
64 x 72 LED wall with ESP32 and WS2812B
I have been making LED signs for many years. This blog testifies to that. However I thought I would take my latest design to the next level and run four of the 16 x 72 LED pannels. When I first started I was using an Arduino UNO in parallel mode using my own code. Then I reconfigured to zigzag format and use used customized code. Now I am using WLED on an ESP32. What I want to do is set up four outputs so I can run four panels and update them from my cell phone.
Here is the first video:
Here is a picture of six panels all working off one ESP32 processor.
Here is the schematic of what I am making to drive the panels.
This is an 8 channel version I am working on:
Is AliExpress a scam?
Aliexpress kept saying my package arrived but was not deliverable, there was a "Delivery Issue". This went on for three or four days. So I went to the post office and asked. They asked for my address and said there was no package for me. The clerk also advised me that several others have also asked for packages from AliExpress. I was told that it was a scam.
Thursday, August 10, 2023
My Equinox failed inspection...
It has been a month of a comedy of errors. My regular place to get the car inspected was having issues with its inspection machine. He said to try back next week. It was still bad the next week, so I called another garage. They were booked for 2 weeks but they could get me in then. Then the problems arose. The brakes started grinding, the check engine light came on, etc. I think the check engine light comes on every year just to remind you to get the car inspected. LOL.
So the brakes were replaced but the check engine was the lower O2 sensor and the catalytic converter. I added some stuff that promised "double your money back if it fails inspection" to the gas. I think it was from CRC. The car came with a spare O2 sensor so I had that installed. Then it came up with several codes all pointing to the O2 sensor. So I went and bought another O2 sensor, but it had a code as well indicating slow response from the O2 sensor. I was starting to think the wiring was bad. At this point I checked the collection of sensors.
The spare that came with the car DID NOT FIT the car! (It did physically)
The replacement I bought was a "universal" replacement.
So I bought an OEM exact replacement and it looked just like the original one on the left in the picture and guess what? After lots of prayer and parts swapping it worked!
O2 sensors |
Monday, July 10, 2023
I have damaged three TV's in a row while trying to fix them.
I am batting three in a row for destroying TV's while trying to fix them. In all three cases all I had to do was replace the LED Backlights. There was the 65" where I disconnected part of a ribbon cable to the screen. Then there was a 55" when after taking it apart at least three times I laid it on its face to attach the back cover and somehow it ended up on its power cord that cracked the screen. Now I have a 50" TV that I have damaged one of the SIDE ribbon cables. I had them all tucked in but when I put on the bezel two of the side cables came out and were damaged by the bezel.
This picture shows the side ribbon cables (The screen is on its other side). The cables loop around and are only about 3/8" long. They tuck into spaces that are alloted for them.
Tuesday, June 13, 2023
CA-300V Super LED tester TV Backlight Review
Years ago I started testing TV LED Backlights with 9 volt batteries. There are even videos of me doing that on Youtube. Well I fianlly broke down and bought a LED tester. The reason was that I had just received a second identical TV to one where I had replaced all of the LED strips and this time I did not want to buy any, but to reuse the good ones from the last TV instead. But I was in for a big surprise. Only two LEDs were bad in the last TV so I was sure I was all set to fix the new one. However in the new TV there were at least 20 bad LED's. Even with 8 good LED strips out of 10, I was still not able to fix all the lED's!! The best I could do was to leave 2 bad LED's. On top of that, as I reasembled the TV two lenses fell off of the strips, so it has to be taken back apart and repaired again!
The short story is that this tester works great. I did have one strip that tested bad in the TV but tested good once it was removed for some reason.
Here is how to test the LED strips. Basically you go + to + on each strip. Note that the strips are not always labeled correctly! The - terminals are usually just shorts. Trial and error is the quickest way to find the correct polarity. You can use a jumper to short out one end of the LED strip if you want to go positive to negative at one end of the strip. Once you replace the bad strips then test everything to make sure it works together before reasembling the TV. Sometimes the LED strip connectors have issues.
This are some really burnt out LED's