Just got my Parrallel LCD, but am having power issues!

Painless

I just received my Parallel LCD (603-00006) from Parallax and hooked it up to the LCD connector on my ET-BASE P40 basic stamp. I've removed all other connections / sensors etc.

The problem is, I can't seem to provide enough power to run the stamp and the LCD. I just connected two 9v batteries in parallel to the stamp, yet I cannot even ID the stamp from my PC unless I unplug the LCD from it. The onboard regulator on my stamp gets warm quick, despite there not being enough power.

How much current is this LCD supposed to need? I can only find voltage references in the PDF's.

Can anyone please help?

Russ.

Mike2545

You should not try to power any peripheral devices from the Stamps on board regulator. Try hooking it up differently.

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Mike2545

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Painless

Well, I just dug out the documentation for my ET-BASE stamp and compared the pinout's from the parallel LCD's PDF to those on my stamp. Unless there's an error in my stamps docs, the pinouts are not the same (despite it providing a 'standard' 14-pin connector).

Vdd & Vss are identical, but the rest of the pins are on opposite sides of the connector. This would explain why the regulator is heating up if it's creating a bad circuit.

I wish I'd known about parallax before I brought this stamp I have, it's an OEM version and I'd rather have paid the money for the parallax original. Hoping I haven't done any damage.

Painless

I just took another look at the two schematics, Vdd and Vss are not correct, basically, what this OEM manufacturer has done is to swap the two 7-pin rows around from what is required by Parallax's LCD. In other words, pin1 becomes pin2, pin3 is pin4 etc. Talk about annoying.

I don't want to mess around with re-soldering my LCD so I suppose I need to find some more 14-pin connectors somewhere and make a converter cable. I'd set aside today to get my LCD running and to understand how to operate it, looks like I won't be doing that now!

Russ.

Painless

Well, assuming that I had quite possibly done damage to the LCD when I first connected it up I decided to go ahead and re-wire the connector properly. Other than the very occasional flickered gibberish I can't get anything from the LCD display. Looks like I blew it up before I even got to use it. I even tried powering the LCD separately.

Hopefully, my experience will prevent someone else with an OEM basic stamp from having the same catastrophe.

Russ.