Archive for February, 2013

7th February
2013
written by Todd Harrison

This is (PART 1). Links to all parts: (PART 4), (PART 3), (PART 2), (PART 1)

A friend has a Kenwood TS-520S HF (high frequency) ham radio. He does not have the optional DG-5 frequency display and calibrating the dials between bands is not much fun. He gave me some information about the DG-5 and through some review I believe I can make a substitute for the DG-5 using an Arduino, LCD Shield and hand full of chips.

He could buy a DG-5 but that would cost more than he paid for the whole rig and it really is not necessary to use the radio, just more convenient.

This is part one so watch this video which covers my idea and some pre-testing. All looks good so far and I’m already working on part two.

 

I got the Arduino frequency library from this site:

http://interface.khm.de/index.php/lab/experiments/arduino-frequency-counter-library/

In the video I just use the library example scketch so I have no code to share in part 1.

 

I also followed some circuit examples shared at these two sites which both built HF frequency counts and were great sources of information to help me on my way to building an Arduino derivative HF frequency counter. My counter is for a single custom application and so doesn’t incorporate all the features these other builds include.

http://aade.com/DFD2inst/DFD2inst.htm

http://www.avr-asm-tutorial.net/avr_en/fcount/fcount_m8.html

 

Arduino website to get development software and sample code:

http://arduino.cc

http://playground.arduino.cc/

 

I got my Arduino and LCD shield from Adafruit.com

http://www.adafruit.com/products/50

http://www.adafruit.com/products/714

 

Some chips and data sheets I have used in part one:

CD74HCT93

Used in 3 bit binary ripple counter mode for divide by 8 with input at CP1 and output at Q3

http://www.ti.com/lit/ds/symlink/cd74hc93.pdf

 

CD74HC153

Dual 4 to 1 Line Selector/Multiplexer

http://www.ti.com/lit/ds/symlink/cd74hc153.pdf

 

Here are some photos of what I covered in part one. CLICK ON PHOTO for hi-resolution image.

 

My Arduino I will be using to count freq and do some line select inputs and math.

My Arduino I will be using to count freq and do some line select inputs and math.

RGB back light despaly by Adafruit.com for my freq display

RGB back light dispaly by Adafruit.com for my freq display

This are the freq I measured coming out of the three RCA jacks on the back of the TS-520S ham radio. I need to count these freq and do some math to know the freq the radio is using.

These are the freq I measured coming out of the three RCA jacks on the back of the TS-520S ham radio. I need to count these freq and do some math to know the freq the radio is using.

I can measure the VFO and BFO with the Arduino directly but not the HFO. I will need to use a prescaler to divide the HFO by 8 before it gets to the Arduino.

I can measure the VFO and BFO with the Arduino directly but not the HFO. I will need to use a prescaler to divide the HFO by 8 before it gets to the Arduino.

The library I'm using is coded to use just the one input so my plan is to use a line select chip to multiplex the three signals to this single Arduino input.

The library I’m using is coded to use just the one input so my plan is to use a line select chip to multiplex the three signals to this single Arduino input.

For a test of the Arduino measuring the BFO freq level directly I just created a nice clean 0-5v square wave at 3.395MHz on my freq generator and put it into the input pin the Arduino is coded to use per the library. As you can see it can count this just fine.

For a test of the Arduino measuring the BFO freq level directly I just created a nice clean 0-5v square wave at 3.395MHz on my freq generator and put it into the input pin the Arduino is coded to use per the library. As you can see it can count this just fine.

I use my leader to valdiate the Arduino is correct.

I use my leader to validate the Arduino is correct.

I then double check the Leader and Arduino with my HP counter. All instruments agree to within a 1Hz. WOW. Nice.

I then double check the Leader and Arduino with my HP counter. All instruments agree to within 1Hz. WOW. Nice.

For the HFO I have to use a MFJ-259 SWR analyzer to generate the higher 10 to 40 MHz signal for testing the Arduino.

For the HFO I have to use a MFJ-259 SWR antenna analyzer to generate the higher 10 to 40 MHz signal for testing the Arduino.

However this instrument only outputs a 1 to 1.5V peak wave which is too low of a voltage level for the Arduino to count.

However this instrument only outputs a 1 to 1.1V peak wave which is too low of a voltage level for the Arduino to count.

Even at the 5MHz level the Arduino only outputs 0 back to the serial monitor on the PC. It could measure the 5MHz but not at the low voltage levels. I will need to build an amplifier before the Arduino can use the SWR output for testing.

Even at the 5MHz level the Arduino only outputs 0 back to the serial monitor on the PC. It could measure the 5MHz but not at the low voltage levels. I will need to build an amplifier before the Arduino can use the SWR antenna analyzer output for testing.

On to testing the divide by 8 prescaler. I output a 4MHz square wave 0-5 v from my function generator.

On to testing the divide by 8 prescaler. I output a 4MHz square wave 0-5 v from my function generator.

I then pipe this 4MHz into the 4 bit binary ripple counter in 3 bit mode. It should output a clean divide by 8 signal at 500KHz

I then pipe this 4MHz into the 4 bit binary ripple counter in 3 bit mode. It should output a clean divide by 8 signal at 500KHz

My Leader records the 4MHz in and the HP records the 500KHz out of the chip so we can compare to the Arduino freq count output.

My Leader records the 4MHz in and the HP records the 500KHz out of the chip so we can compare to the Arduino freq count output.

The Arduino reads spot on with the HP at 499,997Hz

The Arduino reads spot on with the HP at 499,997Hz

This just to show that the Arduino can then do some math to multiply what it counted back to 4MHz  with (frq*8) code.

This just shows that the Arduino can then do some math to multiply what it counted back to 4MHz with (frq*8) code.

Close up showing the Leader which is counting the source at 4Mhz agrees with the Arduino's math down to 1Hz. NICE!

This shows the Leader which is counting the source at 4Mhz agrees with the Arduino’s math to within +/-4Hz. NICE! I only need to be within 100Hz in the end for this to work as a ham radio freq display

That is it for part one. Part two will start with signal amplification then multiplexing and more. I'm not sure how may parts this will end up being but it is fun to share and I hope fun to follow along.

That is it for part one. Part two will start with signal amplification then multiplexing and more. I’m not sure how many parts this will end up being but it is fun to share and I hope fun to follow along.

 

7th February
2013
written by Todd Harrison

Here is a super short video on how to fix those squeaky chairs and stools. They drive me crazy because they are so loud that I wake people at night when using my office chair or when I’m shooting a video and my bench stool squeaks so loud I can’t hear myself talk. They just had to be fixed and it wasn’t that hard.

I hope you enjoy the video and photo gallery below.

My bench stool is upside down. Add some oil between the two pipes.

My bench stool is upside down. Add some oil between the two pipes.

Sand the inner pipe if it is not smooth.

Sand the inner pipe if it is not smooth.

Add some clean bearing grease.

Add some clean bearing grease.

Make sure the bearing grease goes as far down as the stool goes.

Make sure the bearing grease goes as far down as the stool goes.

Add some more oil to the pivit point of the air ram. Clean up before returning the stool to the house.

Add some more oil to the pivit point of the air ram. Clean up before returning the stool to the house.

My office chair upside down.

My office chair upside down.

Oil the spring. Mine is inside the large knob so I put lots on and let it set for an hour.

Oil the spring. Mine is inside the large knob so I put lots on and let it set for an hour.

Add oil to the pivit points.

Add oil to the pivit points.

Remove the clip that holds the legs to the air ram.

Remove the clip that holds the legs to the air ram.

Remove these bearings and clean them before applying clean bearing grease. Put some grease on the air ram too.

Remove these bearings and clean them before applying clean bearing grease. Put some grease on the air ram too.

When the chair is right side up put a little oil between the spring knob and base.

When the chair is right side up put a little oil between the spring knob and base.

Put your air ram retention clip back on and add more bearing grease to this point.

Put your air ram retention clip back on and add more bearing grease to this point.

Office chair is now squeak free.

Office chair is now squeak free.

Use an Allen wrench or whatever you need to really tighten up all the fasteners so you don't get any hardware squeaks.

Use an Allen wrench or whatever you need to really tighten up all the fasteners so you don’t get any hardware squeaks.

My bench stool is now squeak free too!. Thanks for joining.

My bench stool is now squeak free too!. Thanks for joining.

 

  • You are currently browsing the ToddFun.com blog archives for February, 2013.

  • Visit Our Sponsor: MROSupply.com - An e-commerce site of Mechanical Drives & Belting