My Do It Yourself Laser power meter - picture heavy PART1

[lasersbee]

Nice choice for a school project... Did you Photo produce the
boards at school...:thinking:

Once your design works.... don't forget to coat the bare copper
traces so they don't oxidize and turn Green with time..

Can't wait to see the testing phase...:gj:

Jerry

 

[Eudaimonium]

Nice choice for a school project... Did you Photo produce the
boards at school...:thinking:

Once your design works.... don't forget to coat the bare copper
traces so they don't oxidize and turn Green with time..

Can't wait to see the testing phase...:gj:

Jerry

Wow the LPM master himself notices my project.

Actually, if you take a closer look on the part of PCB where are no traces, you can see that it's coated with antioxidans, to prevent the crap you just said it can happen.

Yes I did photoproduce the board. Procedure is more like DIY instead of professional approach, and I accidentally shifted one side 0.5 mm against the other, but it was not a big deal since everything fit right and soldered right.

Tomorrow, I will flash the MCU, and see if it can display the numbers correctly. Once that's done, all I have to do is make a sensor (TEC heatsinked, and coated... BTW, what do you use to coat it? ) and voltage amplifier for it. Oh, and +5V power supply,
Maybe I will make a battery compartment in the enclosure, or some other crazy idea to make this LPM as whacky as it gets.

You got PM also

 

[bloompyle]

Well, our district is $50 million in the hole...we have pretty much NO NEW STUFF, our school isn't even up to fire code, we don't have those little sprinkler things on the ceiling. We can't even afford new computers to replace the dinosaurs we have now that will litterally shut off and kick the bucket while being used, we have to save things onto the server or else we could lose our work. We can't even afford new MICE!! So next year we're stuck with this crap, while our governor wastes money to fund parks....we're building parks, and lightrail bridges, and throwing tons of money to advertise money to legalize, or fight against legalizing marajuana. And all those people paying so much to get it legalized don't think twice about funding weed, but not our schools. And again the governor wastes money on all this other crap that we don't even need before starting the fund the things we DO NEED! All these new thing we hear on the news $125 million on this, $50 million on that. We're putting hundreds of MILLIONS into restoring the gold foil coating on the roof over the governors office...because it's something 'Part of Colorado' well the schools need money, but we AREN'T part of Colorado for some reason??? Our governor needs to stop wasting money and get his head out of his ass and realize that our schools need this money.

 

[ReNNo]

Wow, that sucks.

We in Bosnia also don't have working computers in school or sprinklers
But It's Bosnia.

How can any school in USA be that poor?
it's unbelievable...

 

[Eudaimonium]

Well, our district is $50 million in the hole...we have pretty much NO NEW STUFF, our school isn't even up to fire code, we don't have those little sprinkler things on the ceiling. We can't even afford new computers to replace the dinosaurs we have now that will litterally shut off and kick the bucket while being used, we have to save things onto the server or else we could lose our work. We can't even afford new MICE!! So next year we're stuck with this crap, while our governor wastes money to fund parks....we're building parks, and lightrail bridges, and throwing tons of money to advertise money to legalize, or fight against legalizing marajuana. And all those people paying so much to get it legalized don't think twice about funding weed, but not our schools. And again the governor wastes money on all this other crap that we don't even need before starting the fund the things we DO NEED! All these new thing we hear on the news $125 million on this, $50 million on that. We're putting hundreds of MILLIONS into restoring the gold foil coating on the roof over the governors office...because it's something 'Part of Colorado' well the schools need money, but we AREN'T part of Colorado for some reason??? Our governor needs to stop wasting money and get his head out of his ass and realize that our schools need this money.

Dude, in Croatian schools there is nothing to cause fire with, hence no sprinlers either.

You think you are wasting money...

Croatia is in 40 billion EUROS international dept.

Our former prime minister has €100.000 worth of.... wrist watches.

How about that?
The fact that 70% of population has salaries lower than those needed for decent life does not concern him. He owes €20.000 Rolex , why the EFF would he care?

 

[Ash]

The fact that 70% of population has salaries lower than those needed for decent life does not concern him. He owes €20.000 Rolex , why the EFF would he care?

Capitalism at it's finest. :gun:
Most countries are this way (including the US), with government corruption, corporate greed and "power" as the #1 goal, they are never going to care for the poor. So sad. :cryyy:

 

[Benm]

PCB looks nice and all... even with oldschool LED digits multiplexed on the uC instead of the typical LCD display

But what are you going to use for the laser sensor?

 

[Eudaimonium]

PCB looks nice and all... even with oldschool LED digits multiplexed on the uC instead of the typical LCD display

But what are you going to use for the laser sensor?

Not multiplexed, each segment has it's own port.

LCD was not exactly an option as ordering it online would take too long, local ones cost as if they are made of gold, and I have to finish this in one week or else I'm done for

 

[billg519]

Nice work on Part I !!! I like the pro looking PCB work, really makes for a great looking project. Looking forward to part II ...

 

[Benm]

I didnt look that closely, but i suppose the uC has enough ports to drive a display from each one if you must.

Still - what sensor are you using?

 

[lasersbee]

He posted earlier that he will use a TEC..

Jerry

 

[jbtm]

Looks good! I didn't fully read this but if it's an AVR atmel chip I'll be happy. I program these things all the time. You can count on me making this sometime I am very good at double sided PCB etching with laser printers. The most I made was a board with over 50 parts. Maybe not until the summer, but I do look forward for this, I always wanted a cheap make and if I can, I got 5 ATMEGAS 644P and 32s

 

[Eudaimonium]

Atmel MCU is 8051 based, external 8bit AD converter is used total of 255 combinations posible, but in two mW resolution 510mW is max measured power.

If you program such things, perhaps you will be able to help me out. Here is the problem, I was done with the school yesterday actually, today only some meeting takes place, and I'm outta here

So, professor who is in charge of providing me with programmer board and software is not exactly able to help because board still needs a few... finishing touches.

After the hardware is operational, then software can be written. So, to get the PCB working , I'd sure like access to my equipement back home. But , once I'm home the only time I got back is when I need to show off with this in front of a commission... how do you say it... Present the work, you know.

So, if I will be able to get access to programmer board back home, I can also write it back home. But, if I get stuck here and there, would you be able to help me out?
I'd appreciate it

If you have Eagle 5.80, I can send you the schematics and boad layouts, so you can see what are we dealing with.

EDIT: Yeah, Jerry, thanks - it is a TEC, and operational amplifier to get the voltage where AD converter can work with it.

 

[HIMNL9]

Just one suggestion about your PCB design, if you permit .....

The one in your project made no differences, cause you're not using HF or audio frequencies, but, when you left large parts of the copper between the components (like, for use them as a shielding zones), is always better than you connect all them to GND or, if not possible, to VCC (preferably with a single connection point, if is not an intentional GND loop).

This prevent that, using this system with high frequencies, the "floating" copper zones acts as coupling capacitors between different parts of the circuit, giving you undesired problems.

As i've said, this is only a suggestion, and also, in your circuit, may not cause you any problem ..... just remind it if you want to experiment with high frequencies

BTW, is that interruption on the track over the displays due to a too long etching, or just the photoresist not developed enough ? ..... nice work, anyway, really

 

[Eudaimonium]

Just one suggestion about your PCB design, if you permit .....

The one in your project made no differences, cause you're not using HF or audio frequencies, but, when you left large parts of the copper between the components (like, for use them as a shielding zones), is always better than you connect all them to GND or, if not possible, to VCC (preferably with a single connection point, if is not an intentional GND loop).

This prevent that, using this system with high frequencies, the "floating" copper zones acts as coupling capacitors between different parts of the circuit, giving you undesired problems.

As i've said, this is only a suggestion, and also, in your circuit, may not cause you any problem ..... just remind it if you want to experiment with high frequencies

BTW, is that interruption on the track over the displays due to a too long etching, or just the photoresist not developed enough ? ..... nice work, anyway, really

I always appreciate constructive criticism.

Thanks

So far, 3 jumper wires are used. Curcuit still not operational.

Programming of the MCU is not yet finished, not it will be until 27.6.

I am packing to finally go home now, and I was unable to find te professor who has access to the room with programmer boards.

I will develop the code though this week at home, bring it on USB and finally flash the Eff-ing thing , to get it operational.

Things just tend to lean into disaster... but heck, no project is without one

 

[Benm]

Grounding the copper area is really a HF habit - i used to build things like transmitters for the VHF range, and the habit with those is to have grounded copper plane wherever possible.

In an application like this i think it won't matter at all, its all near-DC running around. The only reason for leaving the pieces of copper is to save etchant. It can be convenient to use a ground plane anyway, especially if they run right past a ground connection anyway.