Rebuild of the 17 DOF Humanoid Robot found on eBay

 In my book "Arduino Servo Projects" I made all kinds of Humanoid Robots.  But none of them were the 17 DOF Humanoid as is found on eBay.  I just could not get it to work.  It has a high tendency to fall over a lot.  In this guys video it fell off the table: https://www.youtube.com/watch?v=-gQDgxQkX-w !  So I spent some time trying to fix him.  One thing I noticed is that his legs are too long.  Even with the higher power MG958 servos when he falls over and I pick him up the servos then go to where they were supposed to.  The servos just cannot lift his weight!  Then as I was studying him I found the mistake!  Can you see it in the pictures below?

Here I am comparing him to the robot from RoboSoul - the HS3 (I made an imitation version and he works just like the real one)

Did you find the problem?  I circled it in red in this picture.  The servo is mounted upside down!

While I was at it I also changed his chest.  The goal there was to make it more like the one that comes in the kit on eBay.  The only difference now is that his head is 3/4 of an inch taller.  I had to move the electronics to the front too.

This first picture is of the new chest bracket on the right.  It closely matches the kit on the left.  The chest is made out of a 3.5 inch piece of three inch by one inch C Channel aluminum.

This is the old chest bracket on the right.  The arms were located higher up and one inch forward of the kit design.  This gave lots of room for the electronics in the back.

I rebuilt my Arduino Servo Arm to use Switches!

This change started as an accident.  Somehow I broke one of the variable resistors that controls the servos in the arm.  So after a while I came up with the idea of using switches instead. For the switches you need 3 position ones.  The positions are on low off and on high.  Then add two 10K resistors across the switch with the two resistors meeting in the middle.  The resulting operation of the arm was much smoother and quieter.  The variable resistors picked up too much noise and that resulted in herky-jerky motion.

This first picture is of the back of the switches.  I used 33K resistors as the value is not critical.

This is the front view of the robot arm controlled by switches.

This is a video of it in operation:

15 DOF Humanoid with PCA9685 and MAX7219

There was not enough pins available on my Arduino UNO to interface a LCD.  I was using 15 pins to control the servos.  So I added a PCA9685 servo controller.  It only uses 2 pins to control 16 servos, thus freeing up many pins for further experiments.  

When I first fired up the PCA9685 shield it quickly smoked.  The polarity protection transistor could not handle the current.  So I replaced it with a jumper wire for now.  The transistor is located next to the power connector near where it says "GND".

Here is the video of the robot:

https://www.youtube.com/watch?v=u30YtSnnPJE

Here are some of the robots facial expressions:

In this picture you can almost see the fear in his eyes!

Changing the head on my 15 DOF Humanoid robot

 I am working on different options for the head or face of my 15 DOF robot.  Today I got a MAX7219 8x8 LED array working with it.  Over the years I have made heads out of Christmas ornaments and some LED's.  But they cannot change their expression.  Now I have added a MAX7219 so the robots expression can change with every command that you send him.  

This picture shows some of the robot heads I have made for my robots with the MAX7219 version in the middle.  As you can see the 8x8 LED array is a little on the small side.  I have some bigger LED arrays that are two and three color, but without the MAX7219 I do not have enough pins left over on the Arduino processor to run them.  Data TX and RX + 15 servos is 17 Pins leaving only three pins that are available to control the face.

Max7219 Humanoid Robot Head

The video is up on YouTube:

https://youtu.be/3wDNV5jnZRc

Hiwonder RoboSoul HS5 Humanoid Robot Demo

 

I have finally been able to run this robot.  I started the project about a year ago.  There was one bad servo that needed replacement.  Then I did not have the arm servos mounted correctly.  But he is up and running now.  You have to assign each servo a number with another interface board and different software before you can assemble the robot.

This is the back view of the robot.  The bus servo controller is not the correct one but it works anyway.

This is the front view of the robot.  I changed his head as the one that came with him was too angry looking.

This is the control screen.  The software was downloaded from hiwonder.

This is a link to the video of the robot working on YouTube:

https://youtu.be/gvBmzbqPedI

72 x 16 WS2812B Addressable LED sign with Arduino Nano

I rewired another of my signs to have all of the LED's wired in series.  They will work with an ESP8266 or newer processor wired that way.  However I have, after a couple of days playing with the programming, done it with an Arduino Nano.  FastLed and AdaFruit NeoMatrix all create a large array then output it. This uses a lot of memory and hence limits the use of older processors. 

My software creates the output directly, eliminating the array stage.  The biggest issue is keeping the software fast.  For instance the Arduino Output "digitalWrite" command cannot be used, it is too slow.  I have to use direct port manipulation.  In the past I have outputted 8 bits to 8 LED strips using that technique.  Hower, by adding some shifting commands to the software I have done the same thing but I am only using D8 to actually talk to the LED sign.

This is what the LED sign looks like from the back side.

Here are some pictures of the text once I got the sign working.

The youTube video is at: https://youtu.be/rKZ0HcD0yVk

Here is the code:

// For Color Text on 1wire, Series wired WS2812 strings
// Features: Bluetooth support, 2 Lines, 5x7 Font
// by: BOB Davis January 2022

// Uses Port B for faster output of data
// Displays 2 lines of text switching between them.
// PORTB is Digital Pins 8-13 (Uses D8 actually)
// Colors: R=Red, G=Green, B=Blue, W=White
// Colors: Y=Yellow, P=Purple, C=Cyan

#define PIN 8 // D0 of port B - Actual pin to send data on

// Variables for colors of letters and background

int red=1; int green=1; int blue=1;

// Format: R/G/B=Foreground then R/G/B=Background then 1/2=line then text
String text1="G1ABCDEFGHIJKLMNOPQRSTUVWXYZ ";
String text2="R21234567890!@#$%^&*()_+{}[] ";
String textn=" "; // New text

// Send the next row to the pin 8 times.
// The delay timing is for an Arduino UNO or Nano.

void sendBits( byte bits ) {
// setting the MSB to 0 reduces brightness + power consumption
PORTB=0x0F; // turn on
PORTB=0x0F; // delay
PORTB=0x0F; // delay
PORTB=0x0F; // delay (add more for faster processors)
PORTB=0x00; // send data
PORTB=0x00; // delay
PORTB=0x00; // delay
PORTB=0x00; // delay
PORTB=0x00; // Turn off
PORTB=0x00; // Turn off
PORTB=0x00; // Turn off

for (int b=0; b<7; b++) {
PORTB=0x0F; // turn on
PORTB=0x0F; // delay
PORTB=0x0F; // delay
PORTB=0x0F; // delay (add more for faster processors)
PORTB=bits; // send data
PORTB=bits; // delay
PORTB=bits; // delay
PORTB=bits; // delay
PORTB=0x00; // Turn off
PORTB=0x00; // Turn off
PORTB=0x00; // Turn off
}
}

// Send bytes to LED's, avoid loops for maximum speed!
void sendPixelCol(byte Col) {
if (green)sendBits(Col); else sendBits(0x00);
if (red)sendBits(Col); else sendBits(0x00);
if (blue)sendBits(Col); else sendBits(0x00);
}

byte font5x7[][6] = { // font from AdaFruit
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Space
0x00, 0x00, 0x5F, 0x00, 0x00, 0x00, // !
0x00, 0x07, 0x00, 0x07, 0x00, 0x00, //"
0x14, 0x7F, 0x14, 0x7F, 0x14, 0x00, //#
0x24, 0x2A, 0x7F, 0x2A, 0x12, 0x00,
0x23, 0x13, 0x08, 0x64, 0x62, 0x00,
0x36, 0x49, 0x56, 0x20, 0x50, 0x00,
0x00, 0x08, 0x07, 0x03, 0x00, 0x00, //'
0x00, 0x1C, 0x22, 0x41, 0x00, 0x00, //(
0x00, 0x41, 0x22, 0x1C, 0x00, 0x00, //)
0x2A, 0x1C, 0x7F, 0x1C, 0x2A, 0x00,
0x08, 0x08, 0x3E, 0x08, 0x08, 0x00,
0x00, 0x80, 0x70, 0x30, 0x00, 0x00,
0x08, 0x08, 0x08, 0x08, 0x08, 0x00,
0x00, 0x00, 0x60, 0x60, 0x00, 0x00,
0x20, 0x10, 0x08, 0x04, 0x02, 0x00, // /
0x3E, 0x51, 0x49, 0x45, 0x3E, 0x00, // 0
0x00, 0x42, 0x7F, 0x40, 0x00, 0x00, // 1
0x72, 0x49, 0x49, 0x49, 0x46, 0x00,
0x21, 0x41, 0x49, 0x4D, 0x33, 0x00,
0x18, 0x14, 0x12, 0x7F, 0x10, 0x00,
0x27, 0x45, 0x45, 0x45, 0x39, 0x00,
0x3C, 0x4A, 0x49, 0x49, 0x31, 0x00,
0x41, 0x21, 0x11, 0x09, 0x07, 0x00,
0x36, 0x49, 0x49, 0x49, 0x36, 0x00,
0x46, 0x49, 0x49, 0x29, 0x1E, 0x00, // 9
0x00, 0x00, 0x14, 0x00, 0x00, 0x00, // :
0x00, 0x40, 0x34, 0x00, 0x00, 0x00, // ;
0x00, 0x08, 0x14, 0x22, 0x41, 0x00,
0x14, 0x14, 0x14, 0x14, 0x14, 0x00,
0x00, 0x41, 0x22, 0x14, 0x08, 0x00,
0x02, 0x01, 0x59, 0x09, 0x06, 0x00,
0x3E, 0x41, 0x5D, 0x59, 0x4E, 0x00,
0x7C, 0x12, 0x11, 0x12, 0x7C, 0x00, //A
0x7F, 0x49, 0x49, 0x49, 0x36, 0x00,
0x3E, 0x41, 0x41, 0x41, 0x22, 0x00,
0x7F, 0x41, 0x41, 0x41, 0x3E, 0x00,
0x7F, 0x49, 0x49, 0x49, 0x41, 0x00,
0x7F, 0x09, 0x09, 0x09, 0x01, 0x00,
0x3E, 0x41, 0x41, 0x51, 0x73, 0x00,
0x7F, 0x08, 0x08, 0x08, 0x7F, 0x00,
0x00, 0x41, 0x7F, 0x41, 0x00, 0x00,
0x20, 0x40, 0x41, 0x3F, 0x01, 0x00,
0x7F, 0x08, 0x14, 0x22, 0x41, 0x00,
0x7F, 0x40, 0x40, 0x40, 0x40, 0x00,
0x7F, 0x02, 0x1C, 0x02, 0x7F, 0x00, //M
0x7F, 0x04, 0x08, 0x10, 0x7F, 0x00,
0x3E, 0x41, 0x41, 0x41, 0x3E, 0x00,
0x7F, 0x09, 0x09, 0x09, 0x06, 0x00,
0x3E, 0x41, 0x51, 0x21, 0x5E, 0x00,
0x7F, 0x09, 0x19, 0x29, 0x46, 0x00,
0x26, 0x49, 0x49, 0x49, 0x32, 0x00,
0x03, 0x01, 0x7F, 0x01, 0x03, 0x00,
0x3F, 0x40, 0x40, 0x40, 0x3F, 0x00,
0x1F, 0x20, 0x40, 0x20, 0x1F, 0x00,
0x3F, 0x40, 0x38, 0x40, 0x3F, 0x00,
0x63, 0x14, 0x08, 0x14, 0x63, 0x00,
0x03, 0x04, 0x78, 0x04, 0x03, 0x00,
0x61, 0x59, 0x49, 0x4D, 0x43, 0x00, //Z
0x00, 0x7F, 0x41, 0x41, 0x41, 0x00,
0x02, 0x04, 0x08, 0x10, 0x20, 0x00,
0x00, 0x41, 0x41, 0x41, 0x7F, 0x00,
0x04, 0x02, 0x01, 0x02, 0x04, 0x00,
0x40, 0x40, 0x40, 0x40, 0x40, 0x00,
0x00, 0x03, 0x07, 0x08, 0x00, 0x00,
0x20, 0x54, 0x54, 0x78, 0x40, 0x00, //a
0x7F, 0x28, 0x44, 0x44, 0x38, 0x00,
0x38, 0x44, 0x44, 0x44, 0x28, 0x00,
0x38, 0x44, 0x44, 0x28, 0x7F, 0x00,
0x38, 0x54, 0x54, 0x54, 0x18, 0x00,
0x00, 0x08, 0x7E, 0x09, 0x02, 0x00,
0x18, 0xA4, 0xA4, 0x9C, 0x78, 0x00,
0x7F, 0x08, 0x04, 0x04, 0x78, 0x00,
0x00, 0x44, 0x7D, 0x40, 0x00, 0x00,
0x20, 0x40, 0x40, 0x3D, 0x00, 0x00,
0x7F, 0x10, 0x28, 0x44, 0x00, 0x00,
0x00, 0x41, 0x7F, 0x40, 0x00, 0x00,
0x7C, 0x04, 0x78, 0x04, 0x78, 0x00, //m
0x7C, 0x08, 0x04, 0x04, 0x78, 0x00,
0x38, 0x44, 0x44, 0x44, 0x38, 0x00,
0xFC, 0x18, 0x24, 0x24, 0x18, 0x00,
0x18, 0x24, 0x24, 0x18, 0xFC, 0x00,
0x7C, 0x08, 0x04, 0x04, 0x08, 0x00,
0x48, 0x54, 0x54, 0x54, 0x24, 0x00,
0x04, 0x04, 0x3F, 0x44, 0x24, 0x00,
0x3C, 0x40, 0x40, 0x20, 0x7C, 0x00,
0x1C, 0x20, 0x40, 0x20, 0x1C, 0x00,
0x3C, 0x40, 0x30, 0x40, 0x3C, 0x00,
0x44, 0x28, 0x10, 0x28, 0x44, 0x00,
0x4C, 0x90, 0x90, 0x90, 0x7C, 0x00,
0x44, 0x64, 0x54, 0x4C, 0x44, 0x00, //z
0x00, 0x08, 0x36, 0x41, 0x00, 0x00,
0x00, 0x00, 0x77, 0x00, 0x00, 0x00,
0x00, 0x41, 0x36, 0x08, 0x00, 0x00,
0x02, 0x01, 0x02, 0x04, 0x02, 0x00,
0x3C, 0x26, 0x23, 0x26, 0x3C, 0x00,
0x1E, 0xA1, 0xA1, 0x61, 0x12, 0x00,
0x3A, 0x40, 0x40, 0x20, 0x7A, 0x00,
0x38, 0x54, 0x54, 0x55, 0x59, 0x00,
0x21, 0x55, 0x55, 0x79, 0x41, 0x00,
};

void sendline(String line) {
cli(); // No time for interruptions!
for (int c=0; c<8; c++){ // shift and send columns
for (int l=2; l<14; l++){ // Send characters
sendPixelCol((font5x7[(line)[l]-32][0])>>c);
sendPixelCol((font5x7[(line)[l]-32][1])>>c);
sendPixelCol((font5x7[(line)[l]-32][2])>>c);
sendPixelCol((font5x7[(line)[l]-32][3])>>c);
sendPixelCol((font5x7[(line)[l]-32][4])>>c);
sendPixelCol((font5x7[(line)[l]-32][5])>>c);
}
}
for (int c=0; c<8; c++){ // shift and send columns
for (int l=14; l<26; l++){ // Send characters
sendPixelCol((font5x7[(line)[l]-32][0])>>c);
sendPixelCol((font5x7[(line)[l]-32][1])>>c);
sendPixelCol((font5x7[(line)[l]-32][2])>>c);
sendPixelCol((font5x7[(line)[l]-32][3])>>c);
sendPixelCol((font5x7[(line)[l]-32][4])>>c);
sendPixelCol((font5x7[(line)[l]-32][5])>>c);
}
}
sei();
}

void setup() {
Serial.begin(9600); // opens serial port, data rate 9600 bps
pinMode(PIN, OUTPUT); // alternative set pin to output
}

void loop() {
if (Serial.available() > 0) {
textn=Serial.readString();
if ((textn[1])=='1') text1=textn;
if ((textn[1])=='2') text2=textn;
}
Serial.println(text1);
Serial.println(text2);

// Pad length to 40 characters
for(int i = text1.length(); i < 30; i++){ text1 += ' '; }
for(int i = text2.length(); i < 30; i++){ text2 += ' '; }

// Read colors from string,
if ((text1[0])=='R') red=1, green=0, blue=0;
if ((text1[0])=='G') red=0, green=1, blue=0;
if ((text1[0])=='B') red=0, green=0, blue=1;
if ((text1[0])=='W') red=1, green=1, blue=1;
if ((text1[0])=='Y') red=1, green=1, blue=0;
if ((text1[0])=='P') red=1, green=0, blue=1;
if ((text1[0])=='C') red=0, green=1, blue=1;

sendline(text1);
delay(4000); // Wait to display results

// Get New foreground and background colors
if ((text2[0])=='R') red=1, green=0, blue=0;
if ((text2[0])=='G') red=0, green=1, blue=0;
if ((text2[0])=='B') red=0, green=0, blue=1;
if ((text2[0])=='W') red=1, green=1, blue=1;
if ((text2[0])=='Y') red=1, green=1, blue=0;
if ((text2[0])=='P') red=1, green=0, blue=1;
if ((text2[0])=='C') red=0, green=1, blue=1;

sendline(text2);
delay(4000); // Wait to display results
return;
}

I have done some basic graphics, in this case a flag.  Basically its one byte per pixel.  Its easy to do as there is no math needed.  The big issue is the need for two 5 volt 15 amp power supplies to power it up.

DR-14830 LED Sign Modification to Arduino Interface

This summer I had purchased a LED sign.  On a closer observation I discovered that I cannot read the model number.  The sign contains two LED circuitboards with "DR-14830" on them.  Since I have been modifing LED signs to work with the Arduino for over 12 years now, this sign was another challenge for me to figure out.  It uses 74LS164 shift registers with ULN2003 drivers for the columns.  The rows are selected by a 74LS164 then a 74LS138 then a ULN2003 then TIP122 power transistors.  The power transistors go to the anodes of the LED arrays.  The row selecting 74LS164 was in the chain of shift registers so I removed it to make the software simpler to write.  

This is a picture of the back panel, as you can see the model number is not readable.

This is a wider view of the back.  It used to have two power sources of 9 VAC that were rectified and regulated to 9VDC for the TIP122 power transistors and 5 VDC for the logic IC's.  I changed it to run off a 5VDC at 10 amps switching power supply instead.

The 74LS138 pins 1, 2, 3 need to be jumpered to the unused 4 pins of the interconnecting jack. Pins 4 and 5 need to be connected to ground and pin 6 goes to 5 volts via another jumper wire.  Also you can see how I changed the power input to be only 5 VDC in this picture.

Before using the 4 unused pins cut the two wire runs that are running to them.  Pin 1 (and 5) is ground so skip that pin and use pins 2, 3, 4 to be connected to pins 1, 2, 3 of the 74LS138.  Existing Pin 7 is data and Pin 8 is clock.

I removed U7 and U8 as they were a phase locked loop (NE556) and a 74LS164 shift register for the 74138 address pins.  Then I cut a run (that was going to the 74LS138) and added the jumper wire in the picture to connect the buffered data to the first 74164 shift register instead of the now removed 74LS164 row selecting shift register.

After a couple hours of troubleshooting the sign started working.  I will eventually upload the software once I get it fine tuned.

Here is the code:

// 60x7 LED Sign driver

// Uses Some direct port writes

// 1/4/2022 by Bob Davis

//#define A   A0  74138 pin1

//#define B   A1  74138 pin2

//#define C   A2  74138 pin3

#define DAT 7 // 74LS164 Data 

#define CLK 8 // 74LS164 Clock 

#define ROW_PORT   PORTC  // Port the 74138 rows are connected to

String text1="ARDUINO UNO ";

// This font from http://sunge.awardspace.com/glcd-sd/node4.html

byte font[][7] = {

0x00,0x00,0x00,0x00,0x00,0x00,0x00, // ascii 32

0x00,0x00,0xfa,0x00,0x00,0x00,0x00, // !

0x00,0xe0,0x00,0xe0,0x00,0x00,0x00, // "

0x28,0xfe,0x28,0xfe,0x28,0x00,0x00, // #

0x00,0x34,0xfe,0x58,0x00,0x00,0x00, // $

0xc4,0xc8,0x10,0x26,0x46,0x00,0x00, // %

0x6c,0x92,0xaa,0x44,0x0a,0x00,0x00, // &

0x00,0xa0,0xc0,0x00,0x00,0x00,0x00, // '

0x00,0x38,0x44,0x82,0x00,0x00,0x00, // (

0x00,0x82,0x44,0x38,0x00,0x00,0x00, // )

0x10,0x54,0x38,0x54,0x10,0x00,0x00, // *

0x10,0x10,0x7c,0x10,0x10,0x00,0x00, // +

0x00,0x0a,0x0c,0x00,0x00,0x00,0x00, // ,

0x10,0x10,0x10,0x10,0x10,0x00,0x00, // -

0x00,0x06,0x06,0x00,0x00,0x00,0x00, // .

0x04,0x08,0x10,0x20,0x40,0x00,0x00, // /

0x7c,0x8a,0x92,0xa2,0x7c,0x00,0x00, // 0

0x00,0x42,0xfe,0x02,0x00,0x00,0x00, // 1

0x42,0x86,0x8a,0x92,0x62,0x00,0x00, // 2

0x84,0x82,0xa2,0xd2,0x8c,0x00,0x00, // 3

0x18,0x28,0x48,0xfe,0x08,0x00,0x00, // 4

0xe4,0xa2,0xa2,0xa2,0x9c,0x00,0x00, // 5

0x3c,0x52,0x92,0x92,0x0c,0x00,0x00, // 6

0x80,0x8e,0x90,0xa0,0xc0,0x00,0x00, // 7

0x6c,0x92,0x92,0x92,0x6c,0x00,0x00, // 8

0x60,0x92,0x92,0x94,0x78,0x00,0x00, // 9

0x00,0x6c,0x6c,0x00,0x00,0x00,0x00, // :

0x00,0x6a,0x6c,0x00,0x00,0x00,0x00, // ;

0x00,0x10,0x28,0x44,0x82,0x00,0x00, // <

0x28,0x28,0x28,0x28,0x28,0x00,0x00, // =

0x82,0x44,0x28,0x10,0x00,0x00,0x00, // >

0x40,0x80,0x8a,0x90,0x60,0x00,0x00, // ?

0x4c,0x92,0x9e,0x82,0x7c,0x00,0x00, // @

0x7e,0x90,0x90,0x90,0x7e,0x00,0x00, // A

0xfe,0x92,0x92,0x92,0x6c,0x00,0x00, // B

0x7c,0x82,0x82,0x82,0x44,0x00,0x00, // C

0xfe,0x82,0x82,0x82,0x7c,0x00,0x00, // D

0xfe,0x92,0x92,0x92,0x82,0x00,0x00, // E

0xfe,0x90,0x90,0x80,0x80,0x00,0x00, // F

0x7c,0x82,0x82,0x8a,0x4c,0x00,0x00, // G

0xfe,0x10,0x10,0x10,0xfe,0x00,0x00, // H

0x00,0x82,0xfe,0x82,0x00,0x00,0x00, // I

0x04,0x02,0x82,0xfc,0x80,0x00,0x00, // J

0xfe,0x10,0x28,0x44,0x82,0x00,0x00, // K

0xfe,0x02,0x02,0x02,0x02,0x00,0x00, // L

0xfe,0x40,0x20,0x40,0xfe,0x00,0x00, // M

0xfe,0x20,0x10,0x08,0xfe,0x00,0x00, // N

0x7c,0x82,0x82,0x82,0x7c,0x00,0x00, // O

0xfe,0x90,0x90,0x90,0x60,0x00,0x00, // P

0x7c,0x82,0x8a,0x84,0x7a,0x00,0x00, // Q

0xfe,0x90,0x98,0x94,0x62,0x00,0x00, // R

0x62,0x92,0x92,0x92,0x8c,0x00,0x00, // S

0x80,0x80,0xfe,0x80,0x80,0x00,0x00, // T

0xfc,0x02,0x02,0x02,0xfc,0x00,0x00, // U

0xf8,0x04,0x02,0x04,0xf8,0x00,0x00, // V

0xfe,0x04,0x18,0x04,0xfe,0x00,0x00, // W

0xc6,0x28,0x10,0x28,0xc6,0x00,0x00, // X

0xc0,0x20,0x1e,0x20,0xc0,0x00,0x00, // Y

0x86,0x8a,0x92,0xa2,0xc2,0x00,0x00,  // Z

};

void setup() {

  pinMode (DAT,OUTPUT);

  pinMode (CLK,OUTPUT);

  pinMode (A0,OUTPUT);

  pinMode (A1,OUTPUT);

  pinMode (A2,OUTPUT);

  Serial.begin(9600);    // opens serial port, data rate 9600 bps

}

     

void loop() {

    if (Serial.available() > 0) {

      text1=Serial.readString();

      }

    Serial.print(text1);

    for (int r=0; r<7; r++){         // Select the Row

      for (int ch=10; ch>-1; ch--){  // select the character

        for (int c=5; c>-1; c--){    // select the column within character

          PORTC=7;                   // Turn display off while shifting

          digitalWrite(DAT, LOW);    // Check of data high or low

            if ((font[text1[ch]-32][c] >> r+1) & 0x01==1) digitalWrite(DAT, HIGH);

          digitalWrite(CLK, HIGH); 

          digitalWrite(CLK, LOW);  // Toggle clock

        }

      }

      PORTC=(r);       // row is done so display it

      delay(1);        // increase to troubleshoot    

    }

  }

This is a picture of the complete sign running.  I am sorry it is out of focus as the LED's are so bright that it overloads the camera.

To daisy chain the sign modules together you will need to extend the 74LS138 address pins to the next assembly.  I added a 4 pin connector to do that but the pins are wired backwards in the picture.  I made a custom cable to reverse the order of pins back to their correct order.

RGB or RGBW LED Strip Quick Controller

I recently had a situation where someone had purchased some RGBW LED strips, but he had no controller and needed the light strips to work within a few hours.  So I took a small piece of circuit board and a 5 position DIP switch and made a quick controller.

On the bottom side the five pin connector for the LED strip just goes to the five pins of the switch.  On the opposite side of the switches the black wire for the strip goes to +12 volts via a switch, the other wires go to ground via the switches.  This can be seen in the next picture.  A 12 volt AC adapter powers the LED strip.

From the top view the switches line up with the colors of the other wires.  That is to say the white wire is "White" LED's. The red wire is Red color, the green wire is Green color, and the blue wire lines up with theBlue color.

UPDATE: I eventually made several mini switch boxes for the LED switches.  

This is what one looks like when installed.

Chevy Aveo Headlight Wiring Burning Up Issue

 My daughter said that one of her headlight was rather dim.  When I opened the hood I immediatly smelled the burnt electrical smell.  I looked at the dim headlight and the ground connector was burned off.  I attempted to cobble the bad headlight connector.  Then when I tested it the other headlight went out.  It had the exact same issue.  

Burnt Aveo Headlight Connector

Burnt Aveo Headlight Connector

The fix is at auto zone,  For 13.99 you get two headlight socket replacement connectors with short wires attached.  The repair kit is Dorman 84790 and it includes two sockets.

Headlight Socket Repair Kit

This is the left passenger side headlight repaired.  You will need to also purchase 6 red crimp connectors.

This is the right, drivers side headlight.  The fill tube for the wipers can be removed to give more room to work.

Repaired Aveo Headlight connector

Chevy HHR Wiring issue - Car will not even try to start!

My car would not start this last Saturday.  The dash would light up but it would not even try to start. The next time I tried it the battery was completely dead.  So I bought a new battery and it still would not start.  Eventually I realized that the radio was dead and the interior lights were dead.  I chased the issue to the "BCM" located on the right side of the center console.  The red/black wire going to it was dead. So I jumped it to 12 votes.  Now the lights and radio worked but it would still to even try to start!  

I checked the fuses at the main fuse box, fuse 4 and 6 that go to the BCM but they were fine.  So I completely removed the fuse box to inspect it and found nothing wrong. Then while searching the internet I discovered that the BCM gets its main power from the battery via a 50 amp fuse next to the battery.  After checking the fuse, I tried putting a test tone on that wire to follow it to the BCM but it was almost completely shorted out to ground.  I removed the 50 amp fuse and cut the wire at the BCM but it was still almost a short to ground.

The test tone on the wire disappeared behind the passenger seat.  So I removed the passenger seat, cut the carpet and exposed the wiring. The carpet was very wet and covered in red rust.  The bottom side of the wiring harness was rotted through, some wires were completely gone.  Some were melted together.  Others were burnt.

This picture shows the burnt wiring harness.

This picture shows the area where the seat was removed and the rust on the carpet.

I do not know where all of the water is coming from, but the water rusted everything and rotted out the wiring harness.

Arduino D1 Mini Powered Watch

 I have been working on a Arduino D1 Mini Powered Watch.  The hope is to add features like the MAX30102 for heartbeat monitoring, and an accelerometer to monitor activity.  So far the time function is the only thing working in the software.

This is the preliminary schematic diagram:

This is the bottom of the circuit board.  The DS1307 is glued on.  The yellow headers are for the D1 Mini.  The top connector is for the SSD1306 and the bottom connector is for the MAX30102.

This is the top side of the circuit board.  There are three switches for "up" "enter" and "down".  They are tied to D6, D7, and D8

The software is on github under bobdavis321.

Two DHT11's to Arduino with OLED Display

 

In this chapter we will first introduce the 96 x 64 Full Color OLED display.  Once again I was able to get the pins to line up so that a header extender can be used to connect the Arduino to the OLED display.  The pin alignment requires that the OLED overlap the Arduino, but the use of a header makes it much easier to add the display.  One pin needs to be bent on the five pin header to skip the Arduino D12 pin.  Then I used short jumper wires for the OLED power and ground as seen in the diagram below. 

 OLED Displays look like a LCD screen, but each pixel is actually an Organic LED.  Because the pixels are LED’s you do not need a backlight like LCD displays use. The use of LED’s also makes the screen much brighter and the colors are stronger than with a LCD screen.

You will need to add the SSD1331 library using the library manager or download it and copy the unzipped file to your Arduino/Library folder.

Next you will need two DHT11’s for this project.  The DHT 11 comes in a three pin or four pin case and can also be purchased mounted on a small circuit board.  The left pin is power the next is the signal and the right most pin is ground.  I soldered jumper wires on my DHT11’s to make easier to connect them up to the Arduino.  The signal wire from one DHT11 goes to the Arduino D2 and the other DHT11 signal wire goes to D3

Next you will need to install the DHT Sensor Library.  You can find the DHT11 support software in the Arduino Library manager.  Then you can download my code from github or type it in from the code below.  If everything is working you should see the Indoor and Outdoor temperatures in Fahrenheit and humidity percent being displayed on the OLED display.

 

I also developed a graphing version.  The video is at: https://youtu.be/Uq36psuKP-g

17 DOF Humanoid Robot with Robot Servos

 I am building another humanoid robot, this time with what are called "robot", double ended, servos.  This picture is what he looks like so far.

I even went a step further and purchased "Serial bus" servos.  They require a special controller and then you need to program them with ID numbers.  This next picture is what a robot bus servo looks like.  Only one end is powered the other end has a servo horn that slips freely.

If you buy five of the LX-224 servos on Amazon they then come with two controller boards.  One controller works with a PC only and the other controller has a built in processor for off-line operation.

Here is the advertisement that got me started on this new robot project.  Only $40 for the metal parts (you need to get the servos and the controller) is a really good deal.  It also comes with bags of screws. You can ignore the boxing gloves in the picture, it has regular hands.

Here is a close up of what the assembled robot normally looks like.

I did not like the angry head that the robot came with, so I changed it to a ultrasonic range finder instead.  This required a new top piece that I made out of some scrap aluminum.  His front cover and battery holder has not been added yet.

For size comparison I stood the new robot next to a humanoid that uses normal servos.  The robot servos are smaller in size resulting in a smaller robot.  As you can see his feet are much bigger, but the rest of the robot is smaller.

This is the robots size chart according to the eBay advertisement.

I have added a battery, processor and all the cables.  Getting close to operating!