Mike M.??? KU4QO
That fake screen clear just scrolls the last line entered on the screen off the top
of the display.? This gives the impression that there is only one constantly
updating data being presented for view.? I found that many lines scrolling upward
across the screen was distracting.?
If using a dumb terminal program that understands all the escape codes it would
be possible to use those to control screen display.? That is not the case with the
Arduino IDE built-in dumb terminal screen.? It is beyond dumb.
This differential voltmeter was built because the Arduino is ground-referenced which makes it difficult to use a single ADC input to measure drop across a resistor
where both ends of said resistor are above ground.? It also works great with
a pair of RF detector probes to measure gain or loss across a stage in your circuits.
There are many ways to change the code so it shows DB, Log-values, and so on.
Arv? K7HKL _._
On Mon, Sep 17, 2018 at 11:27 AM Michael Maiorana < zfreak@...> wrote: Arv, Thanks for posting.
Can you explain the reason for this line in your code?
Serial.println("\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n"); // fake screen clear
I'm wondering if it had anything to do with having issues with re-printing data on the same line in a terminal. I wrote something in the Arduino environment that displayed data every second, and using the Arduino serial monitor it properly kept things on the same line, but no matter what I tried using a regular terminal emulator (like putty) I couldn't get the same result.
Thanks Mike M. KU4QO
|
Arv, Thanks for posting.
Can you explain the reason for this line in your code?
Serial.println("\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n"); // fake screen clear
I'm wondering if it had anything to do with having issues with re-printing data on the same line in a terminal. I wrote something in the Arduino environment that displayed data every second, and using the Arduino serial monitor it properly kept things on the same line, but no matter what I tried using a regular terminal emulator (like putty) I couldn't get the same result.
Thanks Mike M. KU4QO
On Mon, Sep 17, 2018 at 12:16 PM, Arv Evans <arvid.evans@...> wrote: This Arduino based voltmeter is handy for use on the workbench.? It can be built
as a zero-to-5V version, or as a zero-to-50V version.? This is free code, feel free to
modify it to suit your own needs.
----------- Start code ------------- /*
?* Differential Voltmeter
?*
?* by:? Arv? K7HKL
?*????? 16 September 2018
?*?????
?* Measures ADC-0 as A volts and ADC-1 as B volts.? Then computes difference and
?* shows A and B measurements, and A-B difference.
?* Output to both 2X16 LCD and to attached ttl/USB dumb terminal is non-blocking It will
?* work with or without the dumb terminal connected.
?* Arduino can be a Pro-Mini to avoid possible 20 MHz interference from USB-TTL circuit.
?*
?This sketch was adapted from LCD sketch "Hello World!"
? The circuit:
?* LCD VSS pin-1 to ground? [Ground for LCD]
?* LCD VCC pin-2 to 5V????? [5V for LCD]
?* LCD RS pin to digital pin 2? [Register Select]
?* LCD EN pin to digital pin 3? [ENable]
?* LCD D4 pin to digital pin 4? [Data-4]
?* LCD D5 pin to digital pin 5? [Data-5]
?* LCD D6 pin to digital pin 6? [Data-6]
?* LCD D7 pin to digital pin 7? [Data-7]
?* LCD R/W pin-4 to ground
?* LCD VC pin-3 to ground?? // on newer backlighted LCD the Conterast pot is not needed.
?* LCD LED+ pin-15 to +5V?? // Backlight, use 220 to 1K in series for brightness limiting
?* LCD LED- pin-16 to ground [ Ground for Backlight]
?Library originally added 18 Apr 2008
?by David A. Mellis
?library modified 5 Jul 2009
?by Limor Fried ()
?example added 9 Jul 2009
?by Tom Igoe
?modified 22 Nov 2010
?by Tom Igoe
?modified 7 Nov 2016
?by Arturo Guadalupi
?-----------------------------------------------------------------
??? Libraries are wonderful...everybody modifies them and doesn't
??? tell anybody what the changes are.?
?-----------------------------------------------------------------
?This example code is in the public domain.
?
*/
// include the library code:
#include <LiquidCrystal.h>
// initialize the library by associating any needed LCD interface pin
// with the arduino pin number it is connected to
const int rs = 2, en = 3, d4 = 4, d5 = 5, d6 = 6, d7 = 7;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
float a;??? // ADC-0 input (0-1023)
float b;??? // ADC-1 input (0-1023)
float A;??? // a * (5/1023) Volts
float B;??? // b * (5/1023) Volts
float dif;? // dif = A-B
void setup() {
? // set up the LCD's number of columns and rows:
? lcd.begin(16, 2);
? // Print a message to the LCD.
? lcd.println("Differential");
? lcd.print(" Voltmeter");
? delay(2000);? // 2 second delay
? Serial.begin(115200); // serial port baud rate
? Serial.println("Differential Voltmeter");
? Serial.println("A????????? B??????? A-B");
}
void loop() {
? // set the cursor to column 0, line 1
? // (note: LCD line 1 is the second row, since counting begins with 0):
? lcd.setCursor(0, 1);
? a = analogRead(0);
? a = analogRead(1);? // read ADC-0 twice to normalize sampling capacitor
? A = a * (5 / 1023.0);?? // converts ADC-0 out to volts
??????????????? delay(3000);
? b = analogRead(1);
? b = analogRead(1);? // read ADC-1 twice to normalize sampling capacitor
? B = b * (5/1023.0);?? // converts ADC-1 out to volts
? // A = A * 10;? B = B * 10;? // Use this line for zero-50V version
? dif = A - B;
? lcd.print("A= "); lcd.print(A);
? lcd.print("?? B="); lcd.println(B);
? lcd.print("dif=");
? if (A > B) {
??? lcd.println("A>B");
? }
? else? {
??? lcd.println("B>A");
? }
? dif = A - B;
? Serial.println("\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n"); // fake screen clear
? Serial.println("? A??????? B???????? A-B");
? Serial.print(A); Serial.print("????? ");
? Serial.print(B); Serial.print("????? ");
? Serial.println(dif);
}
/*? USER MANUAL
?*?? Use Arduino Nano or Arduino Pro-Mini.? Connect 1602 style LCD as shown in code.
?*??
?*?? Voltmeter range is zero-to-5V.? For zero-to-50 volt range add 100K and 10K
?*?? divider resistors on ADC-0 and ADC-1 inputs, and uncomment line 87.
?*?? "? // A = A * 10;? B = B * 10;? // Use this line for zero-50V version"
?*??
?*?? Set PC dumb terminal baud rate to 115200, or change line 71 to match your dumb
?*?? terminal rate.
?*??
?*/ ---------- end code ----------
Arv? K7HKL _._
|
This Arduino based voltmeter is handy for use on the workbench.? It can be built
as a zero-to-5V version, or as a zero-to-50V version.? This is free code, feel free to
modify it to suit your own needs.
----------- Start code ------------- /*
?* Differential Voltmeter
?*
?* by:? Arv? K7HKL
?*????? 16 September 2018
?*?????
?* Measures ADC-0 as A volts and ADC-1 as B volts.? Then computes difference and
?* shows A and B measurements, and A-B difference.
?* Output to both 2X16 LCD and to attached ttl/USB dumb terminal is non-blocking It will
?* work with or without the dumb terminal connected.
?* Arduino can be a Pro-Mini to avoid possible 20 MHz interference from USB-TTL circuit.
?*
?This sketch was adapted from LCD sketch "Hello World!"
? The circuit:
?* LCD VSS pin-1 to ground? [Ground for LCD]
?* LCD VCC pin-2 to 5V????? [5V for LCD]
?* LCD RS pin to digital pin 2? [Register Select]
?* LCD EN pin to digital pin 3? [ENable]
?* LCD D4 pin to digital pin 4? [Data-4]
?* LCD D5 pin to digital pin 5? [Data-5]
?* LCD D6 pin to digital pin 6? [Data-6]
?* LCD D7 pin to digital pin 7? [Data-7]
?* LCD R/W pin-4 to ground
?* LCD VC pin-3 to ground?? // on newer backlighted LCD the Conterast pot is not needed.
?* LCD LED+ pin-15 to +5V?? // Backlight, use 220 to 1K in series for brightness limiting
?* LCD LED- pin-16 to ground [ Ground for Backlight]
?Library originally added 18 Apr 2008
?by David A. Mellis
?library modified 5 Jul 2009
?by Limor Fried ()
?example added 9 Jul 2009
?by Tom Igoe
?modified 22 Nov 2010
?by Tom Igoe
?modified 7 Nov 2016
?by Arturo Guadalupi
?-----------------------------------------------------------------
??? Libraries are wonderful...everybody modifies them and doesn't
??? tell anybody what the changes are.?
?-----------------------------------------------------------------
?This example code is in the public domain.
?
*/
// include the library code:
#include <LiquidCrystal.h>
// initialize the library by associating any needed LCD interface pin
// with the arduino pin number it is connected to
const int rs = 2, en = 3, d4 = 4, d5 = 5, d6 = 6, d7 = 7;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
float a;??? // ADC-0 input (0-1023)
float b;??? // ADC-1 input (0-1023)
float A;??? // a * (5/1023) Volts
float B;??? // b * (5/1023) Volts
float dif;? // dif = A-B
void setup() {
? // set up the LCD's number of columns and rows:
? lcd.begin(16, 2);
? // Print a message to the LCD.
? lcd.println("Differential");
? lcd.print(" Voltmeter");
? delay(2000);? // 2 second delay
? Serial.begin(115200); // serial port baud rate
? Serial.println("Differential Voltmeter");
? Serial.println("A????????? B??????? A-B");
}
void loop() {
? // set the cursor to column 0, line 1
? // (note: LCD line 1 is the second row, since counting begins with 0):
? lcd.setCursor(0, 1);
? a = analogRead(0);
? a = analogRead(1);? // read ADC-0 twice to normalize sampling capacitor
? A = a * (5 / 1023.0);?? // converts ADC-0 out to volts
??????????????? delay(3000);
? b = analogRead(1);
? b = analogRead(1);? // read ADC-1 twice to normalize sampling capacitor
? B = b * (5/1023.0);?? // converts ADC-1 out to volts
? // A = A * 10;? B = B * 10;? // Use this line for zero-50V version
? dif = A - B;
? lcd.print("A= "); lcd.print(A);
? lcd.print("?? B="); lcd.println(B);
? lcd.print("dif=");
? if (A > B) {
??? lcd.println("A>B");
? }
? else? {
??? lcd.println("B>A");
? }
? dif = A - B;
? Serial.println("\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n"); // fake screen clear
? Serial.println("? A??????? B???????? A-B");
? Serial.print(A); Serial.print("????? ");
? Serial.print(B); Serial.print("????? ");
? Serial.println(dif);
}
/*? USER MANUAL
?*?? Use Arduino Nano or Arduino Pro-Mini.? Connect 1602 style LCD as shown in code.
?*??
?*?? Voltmeter range is zero-to-5V.? For zero-to-50 volt range add 100K and 10K
?*?? divider resistors on ADC-0 and ADC-1 inputs, and uncomment line 87.
?*?? "? // A = A * 10;? B = B * 10;? // Use this line for zero-50V version"
?*??
?*?? Set PC dumb terminal baud rate to 115200, or change line 71 to match your dumb
?*?? terminal rate.
?*??
?*/ ---------- end code ----------
Arv? K7HKL _._
|
Have you built it?
?
Notberto ¨C LU5DNM
?
?
Maybe you see this before but it whorth a check vna with 455
khz if nice concept and very easy to do it at home?
The link
Best to all?
Fernando?
Bs.As Argentina
|
I added a dip meter function to my SNA by using a Return Loss Bridge and a pickup coil.
Added a quick scan function to find the dip over the whole frequency range, and then center it on the display.
https://kv4qb.blogspot.com/2015/06/sna-jr-as-grid-ddip-meter.html
--
DuWayne,? KV4QB
|
Maybe you see this before but it whorth a check vna with 455 khz if nice concept and very easy to do it at home?
The link
Best to all?
Fernando?
Bs.As Argentina
|
This is probably best for US hams because it relates to standard 3/4 inch (1.05 inch OD)
PVC Plastic pipe as coil forms.
Recently I had opportunity to perform tests on 3/4 inch (1.05 inch OD) PVC pipe
as coil form material.? Tests were performed with a 1% capacitor in parallel with
various inductors.? Digital signal generator was coupled to the LC net with a 1.4 pf
capacitor.? A 3.2 pf capacitor was used to couple the LC network to an oscilloscope for for observing voltage peaks.? Coils were close wound with AWG22 enamel covered
copper wire.
1t = 0.055 uh 2t = 0.20 uh 3t = 0.44 uh 4t = 0.75 uh 5t = 1.12 uh 6t = 1.54 uh 7t = 2.0 uh 8t = 2.52 uh 9t = 3.058 uh 10t = 3.63 uh 11t = 4.24 uh 12t = 4.87 uh 13t = 5.52 uh 14t = 6.19 uh
|
Hi Arv, I built this Lab Power Supply out of a Dell ATX computer power supply: https://www.youtube.com/watch?v=WeYK2gY4z-A I had fun building it because I had to study up on all the different power supply form factors that I was not aware of.
Al, N8WQ
On Thu, 13 Sep 2018 13:52:23 -0400, Arv Evans <arvid.evans@...> wrote:
These work well but there is room for improvement.? Add another 2200 to 4400 mfd across the +12V and +5V outputs to filter out any switching transients.??? Add 0.1 mfd across each output to filter out
any RF transients.?
Add an internal LM317 or equivalent and control potentiometer to provide variable voltage output.
Add a DVM module to monitor the variable voltage output.? With a selector switch the DVM can
monitor any of the outputs.
Arv _._
|
These work well but there is room for improvement.? Add another 2200 to 4400 mfd across the +12V and +5V outputs to filter out any switching transients.??? Add 0.1 mfd across each output to filter out
any RF transients.?
Add an internal LM317 or equivalent and control potentiometer to provide variable voltage output.
Add a DVM module to monitor the variable voltage output.? With a selector switch the DVM can
monitor any of the outputs.
Arv _._
|
Qrpguys have a Field Strength Meter which has the 8307 chip on it along with a 3 wire voltmeter ...W1GHZ has a schematic of his power meter (DEMI-ABPF)
Looks line terminate input w/50?ohm resistor and add a few turns inductor on the input cap ... Jim
On Mon, Sep 10, 2018 at 1:05 PM ajparent1/kb1gmx < kb1gmx@...> wrote: For simple meters the issue is hey are linear... DB is 10LOG(p1/p2).
To drive a DMM for logs you must convert a voltage to a log(voltage).
There are logarithmic op amps? and stability with temperature is a common issue.
Another way is is suing diodes.... see above.
The alternate is 8703 of any of the log detectors that do that scaling internally.
Allison
|
Those are popular¡ ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton ¨C J68HZ Soufriere, St. Lucia W.I. Rent it: Like us on Facebook! ? Moderator ¨C North American QRO Group at Groups.IO. ? email:? bill@... ? ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of F1BFU - Fr - 79
Sent: Tuesday, September 11, 2018 3:53 PM
To: [email protected]
Subject: Re: [HBTE] #RF_Detector_Probe ? my RF probe?bought on eBay. ? 2018-09-11 22:32 GMT+02:00 Arv Evans <arvid.evans@...>: RF Detector Probes can also be used with your spectrum analyzer to trace signals through circuits, and to note places where the signal is clean versus where it has ? On Tue, Sep 11, 2018 at 2:28 PM, Arv Evans <arvid.evans@...> wrote: RF Detector probes are very useful, but you have to understand how to use them, and what
?
--
|
Arv
And for the price of $12. I will protect it with a plastic pen. I'll post the photos as soon as it's done.
73 QRO Arv
Gilles F1BFU /FR
Giles
That looks very good.? With power connections it seems to be an "active probe" which
should be good for general use and also for use with a spectrum analyzer to follow signal
paths to see where the signal is clean versus where harmonics and spurs are visible.
Arv _._
|
Giles
That looks very good.? With power connections it seems to be an "active probe" which
should be good for general use and also for use with a spectrum analyzer to follow signal
paths to see where the signal is clean versus where harmonics and spurs are visible.
Arv _._
On Tue, Sep 11, 2018 at 2:52 PM, F1BFU - Fr - 79 <gilles.f1bfu@...> wrote: my RF probe?bought on eBay. Attached photos.
73 QRO Gilles F1BFU / FR
|
I forgot the diagram.
here it is
Gilles F1BFU / FR
RF Detector Probes can also be used with your spectrum analyzer to trace signals
through circuits, and to note places where the signal is clean versus where it has
spurs or harmonics.?
_._
|
my RF probe?bought on eBay. Attached photos.
73 QRO Gilles F1BFU / FR
RF Detector Probes can also be used with your spectrum analyzer to trace signals
through circuits, and to note places where the signal is clean versus where it has
spurs or harmonics.?
_._
|
RF Detector Probes can also be used with your spectrum analyzer to trace signals
through circuits, and to note places where the signal is clean versus where it has
spurs or harmonics.?
_._
On Tue, Sep 11, 2018 at 2:28 PM, Arv Evans <arvid.evans@...> wrote: RF Detector probes are very useful, but you have to understand how to use them, and what
they are telling you.
_._
|
RF Detector probes are very useful, but you have to understand how to use them, and what
they are telling you.
_._
|
Network analyzers run the full range from simple to complex and manual to automatic. There are many on-line advertisements for commercial units and many designs for making
your own SNA.?
What is an SNA?
Building your own SNA is not all that complicated.
There are many more on-line DIY examples of SNA units that have been built by hams.
Arv _._
|
#Hasntags on groups.io discussion groups
#hasntags
Hello
I have been playing with use of hashtags on this groups.io site.? The result indicates
that this may be an interesting way to group related discussions under a single topic,
and thus help with the on-topic versus off-topic problem.
When you start a new topic you can send the email message to groups.io with a "#"
as the first letter in the topic.? The topic needs to be one word, or words that are joined
with something like under-score or dash.? The hashtag system apparently does not like
spaces in the topic label.
I recently sent two hashtag labeled messages to this group.? They are "#Dip Meter"
and "#Q-Meter".? The system stripped the word "Meter" from "#Dip Meter" but kept
the "#Q-Meter" topic label intact.?
To retrieve all posts in a hashtagged topic you can go to and then
to HASHTAGS in the left side menu.? This will list all the posts with that hashtag and
allow you to retrieve them.
Now we have a useful way to group posts under search-able topic labels.
Arv
_._
|
Another test set from older times that is not seen much in our modern
era is the Q-Meter.? It is used to find the Q-factor of components and
circuits.? This is interesting because it lets you predict bandwidth and
efficiency.
_._
|
DuWayne Schmidlkofer
K9HZ
