uLED-128-GMD1

Robo_Benny

Greetings
I am building a miniature CNC drilling machine & would like to use a uLED-128-GMD1 as one of the displays. The plan is to have it come up with our company logo & a simple video. Unfortunately I'm having some touble getting·the uLED·to work.

I have a BS2 rev J on a BOE, connected the uLED per the instructions (using 1k pull up resistor on uLED Rx) & loaded the demo code from the Parallax website. At power up the uLED is blank, after a few minutes· it displays "Device :uLED, X-Res :128, Y-Res :128, Hardware Rev : 10, Software Rev : 12" then it goes blank. A few more minutes later; vertical lines & some garbage. If Rx is disconected from the stamp at power up the uLED will scroll through the 4D Systems screen.

Any help would be greatly appreciated.

Ben Quearry
Production Engineering
Cook Urological & Women's Health

GICU812

Cook Urological & Women's Health


building a miniature CNC drilling machine

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Please Explain [noparse]:D[/noparse]


Sorry I dont have anything helpful to say...

Mike Green

Make sure you don't have the Rx and Tx connections backwards. It sounds like the display is never getting in communications with the Stamp.
I've used this display with a Propeller and it worked just fine. There's nothing fancy the Propeller was doing that a Stamp couldn't do.

Robo_Benny

I have tried reversing the Rx & Tx and I agree it acts like the uLED is not getting signal from the stamp.

I slipped a DEBUG line into the program code (uLED-Demo2.bs2) and it appears that during the "GetACK" subroutine the Stamp is not getting an ACK signal back from the uLED, as it keeps cycling through the "Missed" subroutine.

Thanks again for your help

Robo_Benny

A description of the Mini CNC Drill project;

The basic idea is for a miniature CNC (Computer Numerical Control) drilling machine. Design criteria requires; low initial cost, accurate & dependable and a small foot print (desk top machine). The drill cycle is quite simple; move to position 1, verify location (with encoder on X & Y axis), drill, retract drill, repeat for position 2 through 6, cycle stop. Due to the simplicity and the small size we decided to build our own machine. Here are some links to hardware we are using on the prototype machine;

The table is a Sherline X-Y table with Nema 23 Stepper motors;

http://www.sherlinedirect.com/index.cfm?fuseaction=product.display&Product_ID=766

The drill unit is from Servo Products;

http://www.servoproductsco.com/html/microprocessor-controlled_quil.html

Servo drivers are BiStep 2A units with NCStepper firmware from Pete Norberg;

http://www.servoproductsco.com/html/microprocessor-controlled_quil.html

The frame of the machine that ties it all together will be made in our shop. Last but certainly not least; the control of the prototype machine is from a Basic Stamp. Why·did I choose Parallax to be the core of this project? The support they offer is unparalleled!

Mike Green

Make sure you've connected it properly. There should be a 1K resistor in the Rx lead on the uLED and a 10K pullup on each lead to Vdd.

Robo_Benny

Well, I've got a 1k on Rx (I've tried .22k to 10k) if i put a 10k between Vdd and the uLED "+" the uLED does not come on at all.

Mike Green

As you've noticed, it won't work if you put a resistor in the "+" lead. Just connect it as shown in the diagram on the webstore page. It needs a 5V power supply (Vdd and Vss for ground). Make sure you've got the demo entered correctly.

Robo_Benny

Hey, adding 10k resistors from data lines to Vdd worked! Shame on me for not reveiwing the documentation.

Thanks again!