Member postings for Bob Mc

Hi Stephen..

had a look for anything I could adapt but have nothing suitable... will keep an eye open for you..

rgds..Bob.

Hi Stephen...

I have cut similar threads for my binocular telescope ... see pic below..

It would have been much easier to have a single larger diameter reflector and the Binoviewer ... believe me its a better option than a binocular scope!

To make the adapter would require machining a piece from the solid or better still a circular pipe fitting... will have a scout round in me junk box...but I am not saying I will make it for you ...

Will let you know tomorrow.

rgds...Bob...

Hi Stephen..

I had a similar problem with focussers I bought from China and I know how frustrating it can be...

what I don't understand is that you say one end of a 10mm tube is 71mm internal diameter and the other is a 42 mm male external diameter...?

My suggestion is that if you can buy the tubes with the threads cut in them, could you not cut each tube up and somehow fit them together which is a lot easier than cutting threads.

...Bob..

Thanks again to all who have replied...

I don't mind being put right on this one ... thanks Allan W for spelling it out.. I really do appreciate the responses and will now be ordering a gas det asap.... will make a nice Xmas pressie for the Missus...!!

rgds....Bob..

Thanks to all for your replies..

I don't know why I didn't see the 'gas detectors' as some of you have listed but it was a while ago since I looked..probably forgotten.... links much appreciated.

As I understand it then... the carbon monoxide detector will detect household gas but it is best to have a gas detector as well.

By the way the free fitting service is something to do with the Fire Service, if you are over 65 you are an 'At Risk' person, the chap who turned up checked exit points and gas installations and gave some tips on safety issues and fitted two detectors, I thought it was really good.

Again thanks for your replies.....

...Bob...

Ok.. its not related to model engineering but perhaps there are some of you out there who might throw some light as to why I can't seem to find anything for household use which states it is a Gas detector/sensor.

I had a knock on the door and a real nice guy...a British Gas engineer told me that I was eligible for free fitting of carbon monoxide detectors ... all paid for.. "well put them in" says I; after he had gone I began to think.... isn't carbon monoxide what you get when some volatile vapour such as petrol is burned..?

This don't make sense now... but I admit I don't know much about these things.. I would have thought that carbon monoxide is what you get when perhaps there has been a gas leak and perhaps a room full of gas is ignited...and then carbon monoxide would be present and the detectors would alert me to the fact that the house has just blown up...!!!

Is carbon monoxide the same stuff as household gas itself...? don't know..

I would have thought that sensing a build up of gas would be more appropriate...but I hope to be educated....

...Bob...

Ian....the cat count has changed...!! it all adds up now but it didn't before.... how did the 3 cats become 2...?

Bob.

Ian....

am I missing something....?

it was a travesty of justice that the teacher told him he was wrong in saying the answer he gave in the second paragraph was incorrect...! but I suppose if he did have a cat at home then his answer should have been 8... so the teacher was right in saying he was wrong and Johnny was wrong as he always included the cat at home in his calculations... ... I must get out more often..

Bob..

Hi Peter....

try 'Digital Caliper Remote Display' in the Keyword search title..

Rgds...Bob..

Dave.....you beat me to it....!!!

Hi Dave/Ian...

Dave .... glad to hear you have solved the problem, I was confident you would.

Ian... I know you asked Dave and perhaps he will give some advice, however if you are new to Arduino and having got hold of two LCD board I would imagine they are the LCD version 1 as mentioned in https://arduino-info.wikispaces.com/LCD-Blue-I2C.

I think it best if you get the LCD display program going first ... you need to download the library mentioned at the top of the page of the above website, then there is a small program to download for Version 1.

If you have never had a go at these displays previously please note that if you do not see any characters on the display at first or if they seem a bit dull you use the brightness control on the little piggy back I2C board.

anyway....best of luck.....Bob..

Hi all ...John/Ken

John Haine asks about a 3rd axis display...

the program I posted could be altered for this purpose, but I can only give an indication of what would need to be done, which is to copy one of the sub programs for example 'void Read Y' and change all the Y's & y's to Z & z's

then insert an instruction to 'Read Z' after 'Read Y' was finished...and back to 'Read X' after 'Read Z' is finished, you would also have to alter the Setup & definition parts to include the inputs/outputs etc... I am not able to provide much more info as I am busy making a readout for my mill using a rotary encoder.. you would also need to find a bigger display than I used in my build.. mine could show 3 readings but only on two rows...

Hi Ken... "come a long way" .....yes I only wanted to show it could be done..! to be honest I can't remember exactly where I got the program from perhaps it would be better to wait and see what Dave comes up with as the program I posted has got a lot of superfluous material and wants thinning down, there are certainly a number of people on the www giving programs for this and it does seem the case that most of the cheap calipers are using the BCD format...Binary Coded Decimal.

One of the things that could be done in the meantime is to get an LCD display, mine is a 16x2 character lcd and find out how to write to it... that would be a good start and it is quite simple, if you can get that up and running using an arduino you are half way there... lcd's are about £5 quid on ebay.

Bob...

Hi Duncan../..Dave..

Duncan..Yes you are right...! there are a lot of curly braces in the setup and to be honest I don't know why! but this prog was copied off the www. and since it worked I didn't see any reason to alter it apart from making it read two calipers.. I must admit again that I am certainly not an expert with programming these things, Dave seems to have a far better understanding of programming.

Dave.... you say you have fitted a capacitor to get rid of sporadic readings... I fitted mine at the caliper end which stopped a similar problem... which Neil has done as well.

..Bob..

Hi Dave...

I can certainly commiserate with you "electronics & computers losing their appeal" .

Les is right...the trace definitely looks like a BCD format see .. http://robotroom.com/Caliper-Digital-Data-Port-3.html ...

which means you will be able to use my code..as posted.

I also didn't use the battery in the calipers rather using the +5v from the Arduino for the level shifter... and potting down the 3v3 from the Arduino for the caliper 1.5v supply using two 6k2 resistors.

The LCD I originally powered using the +5v Arduino supply but I found it caused the screen to be a bit dim....the maximum LCD volts is 7v, so rather that making a power supply circuit for this, I found a 3.3v zener and put it in series with the LCD and the 9v Battery... now its as bright as needed.

rgds..Bob..

Thanks Dave for the lcd address program .... will definately have a look at that one.

Thanks Banders who agrees with Neil that the connector is not a good idea, I soldered mine which is a pita as the case needs taking off otherwise the plastic case will suffer...perhaps Dave will find a better solution.

Also thanks Les... I didn't know the label hides the screw...and the hack for getting a remote display from the Wixey is what I want....can't understand how I missed that... I think I will be using a rotary encoder for the azimuth display..

Anyroad up.. I have just been using my new dro and there is a small problem as it seems I selected a couple of resistors for a divider network to give the ~1.5v supply for the calipers, it now transpires that when the battery gets lower in voltage then the caliper voltage goes down as well ...obvious! ...and the readings dissapear..! so I will be removing the bottom resistor and fitting a zener perhaps or could use an LED as a regulator .. not a big problem.

Here is a pic of the dro..

...Bob..

Hi Ken, Dave, Neil ... and all...

Just a short digression... as some of you may know I have an interest in astronomy .. my scope is a 6inch binocular reflector... I have a need for a remote digital azimuth angle readout and wondered if anyone has any information for these things.... see pic.. I can't even get into the thing... or if there are any other types which have a remote readout...

below..pic of scope and below that with angle gauge in question... sorry its blurry but I think you will know the type..

rgds..Bob..

Part 2.

int i;
int sign;
long value;
float resultx;
float resulty;
int clockpinx = A2;
int datapinx = A0;
int clockpiny = 7;
int datapiny = 9;
unsigned long tempmicrosx;
unsigned long tempmicrosy;

#include <Wire.h>

#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);

void setup()
{
{pinMode(clockpinx, INPUT);
pinMode(datapinx, INPUT);
}
{
pinMode(clockpiny, INPUT);
pinMode(datapiny, INPUT);
}

Serial.begin(9600);

lcd.begin(16,2);
lcd.backlight();

{ lcd.setCursor(0,0);
lcd.print("X val mm";

lcd.setCursor(0,1);
lcd.print("Y val mm";
}

}

void loop() {
ReadX();

}

void ReadX(){

//This is for reading the caliper x data.

while (digitalRead(clockpinx)==HIGH) {} //if clock is LOW wait until it turns to HIGH
tempmicrosx=micros();

while (digitalRead(clockpinx)==LOW) {} //wait for the end of the HIGH pulse

if ((micros()-tempmicrosx)>1000) { //if the HIGH pulse was longer than 1000 micros we are at the start of a new bit sequence
decodex(); //decode the bit sequence

}
}

void decodex()
{
//this turns the binary code of x data into a decimal value.
sign=1;
value=0;
for (i=0;i<23;i++) {

while (digitalRead(clockpinx)==HIGH) { } //wait until clock returns to HIGH- the first bit is not needed
while (digitalRead(clockpinx)==LOW) {} //wait until clock returns to LOW
if (digitalRead(datapinx)==LOW)

{
if (i<20)

{
value|= 1<<i;
}
if (i==20)

{
sign=-1;
}
}
}
resultx = ((value*sign)/100.0);
lcd. setCursor(10,0);

lcd.print(resultx,4);

ReadY();
} ///END

void ReadY(){

//This is for reading the caliper Y data.

while (digitalRead(clockpiny)==HIGH) {} //if clock is LOW wait until it turns to HIGH
tempmicrosy=micros();

while (digitalRead(clockpiny)==LOW) {} //wait for the end of the HIGH pulse

if ((micros()-tempmicrosy)>1000) { //if the HIGH pulse was longer than 1000 micros we are at the start of a new bit sequence
decodey(); //decode the bit sequence

}
}

void decodey()
{

sign=1;
value=0;
for (i=0;i<23;i++) {

while (digitalRead(clockpiny)==HIGH) { } //wait until clock returns to HIGH- the first bit is not needed
while (digitalRead(clockpiny)==LOW) {} //wait until clock returns to LOW
if (digitalRead(datapiny)==LOW)

{
if (i<20)

{
value|= 1<<i;
}
if (i==20)

{
sign=-1;
}
}
}
resulty = ((value*sign)/100.0);

lcd. setCursor(10,1);
lcd.print(resulty,4);

ReadX();
}

So... I finally finished it...

(I can't post all of this in one go on the forum) this is Part 1. Program is Part 2.

Ken did mention an IC level shifter which is a better idea, but I had a load of small signal transistors in me junk box and I was getting impatient... so just cobbled it together.

The 1.5v supplies for the calipers were simply taken from a potential divider which has a 6k2 connected to the 3v3 output of the Arduino and a 4k7 down to ground 0v ... gives about 1.4v at the mid point.

The wiring to the Arduino is best followed using the program inputs .. you will see clockpinx and datapinx and clockpiny and datapiny defined.

I used a D type connector for the two calipers.. there is not much wiring to do, I did however wire reset to zero switches in the box which just ground the reset buttons in the calipers, you would have to take the calipers apart to fit wiring and I must say it is a bit fiddly, there is not much room for manouver... or is is manouvre sorry can't spell.

One thing which was different with the Lcd I purchased was that the I2C address was slightly different but there seem to be only two addresses used.... either 0x3F of 0x27.

The program below is for use with two calipers which I just put together with a minimal knowledge of programming and copying what was on the www.

Hope you might find some of the build info useful.. if you have any questions let me know ... just don't ask me difficult questions about programming..!!

Thanks Ken, Dave, Ian..

Yes Ian... I got an email advert this morning about the bluetooth connection app for a digital caliper... but could the idea be used in a 2 or 3 axis requirement..? .

The other thing is that I am actually only going to use one caliper on the Y axis on my milling machine as there is not much travel, however the X axis is quite long and I intend to use a rotary encoder which I purchased some time ago and am determined I am going to use it on something!

Anyway... the real reason is that I get such a feeling of satisfaction from doing things my own way and when it works and looks the part I am on cloud 9...!

Thanks for all your posts ... it is a real buzz to get appreciation.

Bob..

Have been doing some more work soldering the Arduino Nano and level shifting components on the pcb, this is done prior to fitting the pcb in the box, I am 'hot glueing' the LCD and veroboard pcb in place, it can be removed if necessary with a bit of heat .

I will be trying this set up using a caliper for the 'y' axis only ... I intend to use a rotary encoder for the 'x' axis, and as you are only interested in one axis display I won't be showing any of the rotary encoder workings.

pic below.... the pcb component side .. minus transistors...you may note I have two sets of components either side of the Arduino, this is initially for the two sets of level shifters ie, one for 'x' axis calipers and one for 'y' axis caliper.. for a single axis you obviously only need to have one set of these.

Below ... the other side but not yet cut the tracks .

Below...I cut out a slot to take the Arduino mini usb port and trial fitted the board.

So... its coming on... hope to have it up and running in a day or two...and let you see the program ... just hope all Arduino experts are not looking... but hey who cares ! ... so long as it does what it is supposed to do.

..Bob...