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USB LPM Screen Addon

Trevor

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Here's a little project I did one afternoon... really just for the sake of doing so.

USB-only LPM equipment entered the market in 2010 with the Kenometer USB, which was quickly followed by the LaserBee 2.5W USB, the LaserBee 3.7W USB, Jerry's "DL-Module," and, later, the Delta Isis. These are all great devices, but lack an LCD screen. All these products lack an LCD screen for different reasons - some due to a desire to lower costs, others due to the fact that they're just basic dataloggers.

Either way, it seemed like a fun project, if for no other reason than to prove it could be done.

Code

This is pretty simple. Each time you want to update the screen, you flush the incoming serial buffer.

Then, read the bytes coming from the LPM until you see a termination character, and discard those bytes. This clears any partial incoming data packet.

Last, read data until the next termination character. That will give you a whole data packet to parse.

All hobby LPM's ever made have used a human-readable packet format, so they're all really easy to interpret.

Wiring

I hooked up an Arduino Nano and an LCD on a breadboard. Because the LaserBee 2.5W USB I used in this project outputs standard RS-232, I needed to invert the signal so that it could be read by an Arduino. I didn't have anything laying around I could make a NOT gate with... so I just used another Arduino. :p

Here's the setup, though the NOT-gate-Arduino isn't set up yet. Please forgive the messy wiring. :)



And here's the other bit of the setup. It's a LaserBee 2.5W USB with the serial output hooked up to the breadboard. No surprises to speak of.



Results

Here's the final product! You can see the Arduino acting as a NOT gate up at the top of the photo.



So there you have it. To add a screen to an LPM without a display, all you need is a $5 16x2 character LCD, a $13 knockoff Arduino, some perfboard to build on, and mad solder-blob-dragging skills.

I used a graphical LCD just because I already had LumenOS - but this can be done much more cheaply!

Anyway... I'm not sure who this is useful to, but happy modding!

Trevor
 



Speedy78

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Would love to add a flip up screen for random tests to my Nospin but have no idea what half of this thread even means :)
 

Trevor

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Well... basically all an addon likes this does is read the datastream that would ordinarily be read by the computer.

So you could turn your datalogging-only LPM into a datalogging LPM with a display. :D

Trevor
 

Trevor

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Nope! This sort of thing is intended to be an unintrusive way of adding a display.

So, if you decided to do it in your nospin LPM with the ARGraph addon, the dataflow would look something like...

HTML:
            Signal Voltage
                  |
                  |
                  V
               ARGraph
                  /\
                 /  \
                /    \
               /      \
              /        \
             /          \
            V            V
        Computer        LCD
The display addon just listens in on what the datalogger is spitting out - all that happens to the datalogger is a bit of soldering so that the data signal can get to the addon.

Trevor
 

Speedy78

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Well the data logger is an arduino so would I be able to plug something into this that reads the data?
 

Trevor

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Well the data logger is an arduino so would I be able to plug something into this that reads the data?
Do you mean adding an LCD to the Arduino that already lives in your nospin LPM?

That's totally doable, but would require a firmware change. Is the ARGraph source publicly available? I forget.

Trevor
 

ARG

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That's totally doable, but would require a firmware change. Is the ARGraph source publicly available? I forget.
Yup! It's in a folder on my desktop. Somewhere :p
 

Speedy78

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Yeah all I physically think I would need to do is plug it in and let Alex work some magic.
 

ped

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Trevor reminds me of NEO in the opening scenes in the Matrix, rummaging round a draw full of disks (well, usb sticks now) , thinking "I know I have the software somewhere" :p
 

n2stuff

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Trevor reminds me of NEO in the opening scenes in the Matrix, rummaging round a draw full of disks (well, usb sticks now) , thinking "I know I have the software somewhere" :p

Trevor needs to upload himself so he can keep working for ever :tinfoil:
 

Blaster

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This is a great idea to have a display as well as the data logging tHank's Trevor great work again +1 if system allows
 




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