Gemmasta Encoder Mod Thread

[MakkyBrown]

Hi Rusted,
Have you got it wired up? Screen going etc, if you want you can post it to me and I'll see if I can get the program going for you.
Cheers
Andrew

[Rusted]

Thanks for that offer Makkybrown.

I haven't really had a good play with the thing for quite a while, the display was what was stopping me and I couldn't get past that, I just had so much on my plate that the encoder just went onto the backburner.
This year I didn't put my hand up to be the President of the Gem Club so I am looking forward to a bit of time to do my own things.
1. Get encoder going.
2. Cut some stones.
3. Go fossicking.


Paul.

[MakkyBrown]

What's Rusted encoder part number? Is it still having teething problems?
If it is differential I think it would work as single ended (that is where a scope comes in handy). But it would just as easy to use it as a differential. But he will need a line receiver the same as I have used. If he wants I can send one out (They came in a pack of five)

OP,
You'd better have a look at Rusted encoder.
https://www.ia.omron.com/product/item/2391/
I didn't realize you could get line receivers and haven't read what they exactly are/do.
I was thinking he could wire his encoder in a push/pull arrangement or just on the +ve wires.

Paul,
Sounds like you have a great year planned.
Cheers
Andrew

[Orange Pirate]

What's Rusted encoder part number? Is it still having teething problems?
If it is differential I think it would work as single ended (that is where a scope comes in handy). But it would just as easy to use it as a differential. But he will need a line receiver the same as I have used. If he wants I can send one out (They came in a pack of five)

OP,
You'd better have a look at Rusted encoder.
https://www.ia.omron.com/product/item/2391/
I didn't realize you could get line receivers and haven't read what they exactly are/do.
I was thinking he could wire his encoder in a push/pull arrangement or just on the +ve wires.

Paul,
Sounds like you have a great year planned.
Cheers
Andrew

Definitely differential. You may be able to connect it single ended by just using the A, B and Z but I can't be sure. If have access to a scope that would help.

But may as well make most of the differential option to remove problems of interference. It's basically how they transfer data signals around noisy environment's like automotive (CAN Bus). They take the initial encoder output and puts it through a chip called a line driver that split's into two signals, high and low/inverted (A and A-) So what happens on one wire, happens on the other but the difference remains the same. So when it's converted back to a single output by the line receiver, it's perfect. That's about all I know and probably not entirely correct.

The line receivers are cheap but I had to buy a min of 5 (am26c32). So I have a few spare. PM me an address and I can send one over with an IC socket. You will still need some resistors (X3 + 1) and capacitors (X3 + 1) (can't remember the value's I used ,theoretically is different for each project, but can PM that)

cheers
OP

[Orange Pirate]

This project of mine is cursed.


Finally, finally got it working after 9 months. The problem I had was I programmed the chip to interrupt on an input that wasn't connect. So every time interference occurred it would miss counts


SO it was sorted. Nice big screen, big numbers. The rpm counter was working. It was a piece of art.


So where are the pics. Well I had it all assembled and mounted in a nice plastic box. Connected it up and 'POP!". The short story is a mounting screw, or point (unsure) touched the back of the board and shorted the 12V rail to the 5V. Complete destruction.


Now I'm just pacing in complete disbelief. Aaaaahhhhhhh...................................

[Jimnyjerry]

What a cow of a thing to happen. 

Hope you recover soon.

Are you going to start again?

Could have been worse. Saw a utube video recently of a SUV that combusted because they had a generator running next to a kero lamp in the back of the vehicle.  First time campers near Uluru. At least their caravan did not burn.

[Orange Pirate]

What a cow of a thing to happen. 

Hope you recover soon.

Are you going to start again?

Could have been worse. Saw a utube video recently of a SUV that combusted because they had a generator running next to a kero lamp in the back of the vehicle.  First time campers near Uluru. At least their caravan did not burn.

So do I. Other wise my head is going to fall off from all the shaking in disbelief I'm doing. 


I'm going to have to Jerry. It's not the amount of money that went up in magic smoke. It's the research. Being a complete novice I have to start again figuring out all the component values and the circuit design was done on the fly. So no diagram either. Boo hoo!
On the bright side. Mk 3 will be bigger, brighter and faster. With added circuit protection. 


I wonder if the sunset on the rock had an extra special strange flickering look to it that evening



Cheers
OP

[MakkyBrown]

This project of mine is cursed.


Finally, finally got it working after 9 months. The problem I had was I programmed the chip to interrupt on an input that wasn't connect. So every time interference occurred it would miss counts


SO it was sorted. Nice big screen, big numbers. The rpm counter was working. It was a piece of art.


So where are the pics. Well I had it all assembled and mounted in a nice plastic box. Connected it up and 'POP!". The short story is a mounting screw, or point (unsure) touched the back of the board and shorted the 12V rail to the 5V. Complete destruction.


Now I'm just pacing in complete disbelief. Aaaaahhhhhhh...................................

Bugger, is your encoder ok?  It's so easy to do, we been collecting a few blown up components on my sons robots lately. I connected a voltage regulator up with reverse polarity and it went off like a fire cracker. You could always swap to ardunio and I'll give you all my code, I'm about to pull the mega out of mine and put in a pro-mini, they are only $2 from china and should do the job.
Don't give up.

[Orange Pirate]

Unfortunately complete destruction from that one tiny over sight. The only thing I worth saving was the heat sink for the regulator. The graphics program for the screen and the encoder program are both on the lappy. I still have heaps of spare micro-controllers. The next board I'll solder in a zener diode and fuse. But thanks for the offer. The PIC I'm using has so much interrupt capabilities, it's perfect for the job.


Definitely not giving up. It was looking and working nice. Big bold inch high yellow digits on a black background, immediate update. Just some work on the screen graphics to do.
Must admit I am balking at the thought of buying another encoder. It's bad enough seeing the price in merican $'s without the postage.   


Cheers
OP

[MakkyBrown]

You might be able to just get a new reader for the encoder which will save a bit or did it  all melt  . Taking interrupts, we are using a library for ardunio that opens up heaps of extra interrupt pins. The robots have 19 interupts running each. All measuring pulse lengths from various sensors.
I think even on a small pro-mini you can activate most pins as interupts.
Encoders, you might be able to get an Avago? spelling one cheaper. Could be worth having a look on Aliexpress, something might have appeared. I've also had some success with some of the larger Chinese ebay sellers getting me things they don't stock. GC Supermarket is good.

[Orange Pirate]

No melt down. Death was silent but violent except for the exploding cap and a glowing red hot component on the display.


I've been checking out these Atmel chips. I like the idea of interrupt capabilities on all pins. But I like the range of PIC more. Even if I went to Atmel , just not an arduino fan, each to their own though    - just to much extra bulk, the board and the boot loader. I originally started with Picaxe , which is a Pic with a boot loader. But after using 'Flowcode', programming is just way too easy.


As for a replacement encoder, I'm just going to bite the bullet and buy another US digital. Although I did have a quick look around for a replacement, if I procrastinate too much it won't happen. Although finding somewhere up here that has a Fax (US Digital is order by Fax) that has capabilities outside Queensland seems to be the hurdle at the moment.
I also had a look at that GC Supermarket. Good gear on there.
The replacement screen has already arrived and the replacement board should arrive early next week. Version III is a go.


Cheers
OP

[MakkyBrown]

I think I've just joined the blownup encoder club , I think I plugged the encoder to display unit cord plug back to front. Mega is dead, just had got it working again. Hoping the encoder reader is ok but I don't like my chances. Have you ordered replacement encoder OP?
Will assess it tomorrow 

[Orange Pirate]

That is not good MakkyB. I feel your pain. Welcome to the club you didn't want to join. 


You may be OK. I noticed some stuff is polarity protected. I ordered my encoder weeks ago before I started to procrastinate although I have avoided looking at the invoice. 


I have my circuit built, display running and the RPM side working. But because of my last disaster, I'm adding a 'crowbar' circuit to avoid anything over 5.2V and a diode for reverse protection before the encoder gets plugged in again. Lesson learned. I'm waiting for parts.

[MakkyBrown]

I think I might have been a bit lucky. Put in a new mega and atleast the screen goes. Have removed the depth of cut code and found a simple library for the clock so it now has the time. The big test will be when I test the encoder tomorrow.

[MakkyBrown]

  Fixed 


Removed DOC and got the clock going. Clock was really easy as a new library had appeared since I was last looking at it.
Something is still not quite right when I turn it on sometimes as the screen doesn't go. I think the screen might be a bit faulty, but atm it's going and usable and I didn't blowup the encoder reader I might look to getting a different screen, preferably one with a serial interface to get rid of all the wires. Looking at my/Toms encoder code again, gee it's straight forward after helping my son build/program his robots.
Looking at the screen pic again I should add the date and it would only be adding/changing a line or two of code. Great little clock module, only about $1 off ebay. I found a simple but powerful library to use with it.  It has a small battery so the time isn't lost when the encoder unit is turned off. Would be easy to make a stop watch so you can time how long it takes to cut a stone.

Cheers

Andrew