Monday, July 27, 2015

2.2 or 2.4 or 2.8 inch SPI TFT LCD ILI9341 to Arduino Uno

Over the weekend I figured out how to interface a 2.8 inch SPI TFT that has a ILI9341 chip to an Arduino Uno.  All it takes is eight 1K resistors.  Most people use a 4050 IC.  Here is the schematic.

I am using the Adafruit ILI9341 driver found at: https://github.com/adafruit/Adafruit_ILI9341
Note that the Adafruit LCD has level shifters for 5 volts built into it.

Here is a video of it working on Youtube.

Here is a video of the LCD being used as an oscilloscope.


Here are a couple of still pictures, only 6 of the 8 bits are connected for these pictures.


Sunday, July 19, 2015

2015 Batavia NY Hamfest

This year I made it back to the Batavia NY Hamfest!   It was bigger than most of the Hamfests that I make it to.  The picture only shows one of two isles of equipment for sale.  I forgot my camera and it was dark so my cell phone pictures are not that great, sorry about that.

Here is my stuff for sale.  The car does not fit as much stuff as the van did.

Thursday, July 16, 2015

Walking "Humanoid" Robot found on eBay.

My book "Arduino Robotics Projects" ended with a walking dinosaur.  I might eventually write a sequel to that book with a spider and a humanoid robot.  One of those projects that I have been working on is a walking "Humanoid" robot.  Recently I completed building the legs.

Here are some of the many parts that comes with the robot found on ebay.

Here is the actual parts list:
- 16 x Multi-functional servo bracket
- 7 x Short U-type servo bracket
- 4 x Long U-type servo bracket
- 4 x Angled U-type servo bracket
- 4 x Flat servo bracket
- 4 x L-type servo bracket
- 1 x U-type robot waist bracket (not pictured, I made my own)
- 2 x Foot Base
- 14 x Miniature Ball Radial Bearing
- 17 x Metal Servo Horn Flange
- 1  x Screw and nut set

You will also need flanges, bearings and lots of screws.  Do not use the pictured 16 channel servo controller you will need a 32 channel servo controller.

You will also need about 17 servo motors!  Here is a few of them, they are MG995's.

Here is how to assemble the feet.  Use the flat head M4 screws as seen on the right side.


There are two ways to mount the bearing as seen on the left in the above picture.  You can put the screw in first and then bend the "U" metal bracket over the screw and bearing.  The other way is to use tweezers to hold the nut in place and then put the screw in as seen above.

When I started I used the wrong screws to hold the servo's in place.  You are supposed to use the M4 screws (A little bigger than a 6-32 screw) but I used the M3 screws (about the size of a 4-40 screw) instead.  I am in the process of changing all of the servo mounting screws.  Also my guess is that the four screws used to hold the servo flange to the "U" bracket are supposed to be flat head screws.  The rounded or pan head screws are for the center of the flange to fasten it to the servo.

I am making my own breast plate that looks better than one made out of small parts.  It is made out of a left over 4 inch piece of 3 inch "C" channel removed from a 19 inch rack.

Here is the completed and painted chest piece.

I have assembled the robot with the home made chest.  I used 1/2 inch spacers to move the shoulder servo's out to where the head mounting bracket fits between them.  Note that I only used 4 servo's per leg, I think that is all that is needed.



Thursday, July 2, 2015

Arduino 50 MSPS DSO Oscilloscope with TDA8703

Last night I was testing a TDA8703 analog to digital converter and after trying 36 MHz I tried 50 MHz on a whim and it worked.  I also tried 60 MHz but the TDA8703 flaked off at that speed.

Here is a picture of the test setup.

This is what the LCD screen looks like.

Here is the video of it at 50 MSPS and 25MSPS.


Here is the schematic diagram.

Tuesday, June 30, 2015

Arduino 5MSPS Oscilloscope revisited.

I have been testing various fast analog to digital converters with the Arduino.  There are two  objectives. I want to see if I can improve the old CA3306 version by getting rid of the glitches.  I want to add a FIFO that can push past 10MSPS as that was the fastest rate achieved previously.

The first picture is of a rebuilt version of the CA3306 circuit.

Next I tried a TLC5510.  The results were a bit noisy as seen in the next picture.

A picture of the TLC5510 screen.  The noise might not be the fault of the A to D converter.  The noise was cured by synchronizing the clocks.

TDA8703 Analog to Digital converter being tested.  At first it did not work until I increased the power from 4.2 volts (from USB) to 5 volts via an AC adapter.

I found a way to synchronize the clocks and thus reduce the amount of glitches!  Here is the video.


Here is a Youtube video showing the TLC5510 running without the clock glitches.


Here is a video showing a completed Arduino Oscilloscope with working selection switches.

The second civil war is getting closer to reality daily!

Years ago I talked about the second civil war.  Here is one of several posts:  http://bobdavis321.blogspot.com/2011/03/more-on-upcoming-second-civil-war.html

Now in light of that, the banning of the confederate flag makes sense!  Why ban the confederate flag while allowing the swastika and the ISIS flags to be sold?  Simple, they know the second civil war is coming and they want to stop it.  Now first of all lets get our facts right.  The civil war was not just about slavery!  It is called the "confederate flag" because they were against "con" the "federate" or federal powers.  You see the federal government was usurping too much power and some states wanted out of the union.  The other army was called the "Union" army for the opposite reason, they wanted to keep the union of the states.  So, now do you see why they are banning the confederate flag?

Why are we not fighting ISIS?  It is for the same reason.  The federal government needs to keep lots of troops here in the US to "keep the peace" while it continues to usurp way too much power.  Enter "Jade Helm" a "military exercise" throughout the southern (confederate) states.  This excuse allows the federal government to flood the confederate states with troops ready to fight to keep government control of those states.

I know this sounds like a bunch of conspiracy theories but unfortunately it has become reality.

Now add the upcoming stock market crash.  As the Greece economy collapses, France, Italy and Puerto Rico are also on the verge of bankruptcy.  The 18 trillion dollar debt this country owes is only the tip of the iceberg.  Internationally there is over 160 trillion in debt.  You can keep borrowing to pay the debt and "Kick the can down the road" for only so long.  Sooner or later the debt has to be paid.  If all of the money that is printed in the world was all bought together in one pile it could not even pay a fraction of the total debt!

So again I propose a solution.  Dissolve the US and split it into smaller countries - as in the second civil war.  If the US does not exist then its debts do not exist.  In any case this massive debt is going to lead to a lot of countries into declaring bankruptcy.

Also this whole "gay marriage" thing is not just about gay marriage.  It is about legitimatizing the homosexual lifestyle.  Just as abortion made "sleeping around" more legitimate, "gay marriage" makes being gay more "legitimate".  Only less than .1% of the population have had a 'gay marriage".