Except I've never bought a 40X2 so I have nothing to try.Dunno, but it's easy enough to test. You can't hurt anything, either it works or it doesn't. By now you could have tried it and let us know.
I have looked at the datasheet and I could not find the answer. 'Course, pretty much I've yet to find any answer in that massive thing so no surprise. Without a chip to test I'm SOL, so I'll just order a chip and test later.
Maybe the extra pins are there, just to cater for the occasion when all those GPIO pins are sourcing/sinking 25mA each? (which is of course, what you were saying in the first place )I have looked at the datasheet and I could not find the answer
The pins are connected within the chip BUT the path cannot tolerate much current. The resistance is relatively high: two tiny wires connect the external pins to the silicon and there are paths through the silicon. Capacitors should be mounted as close as possible to the pins anyway - remember that most of the electrical noise on those power pins is generated within the chip.I suggest testing the resistance between the supposed same function pins - should give a clue if they ARE the same... ;-0 [note those tiny wires can be melted... don't use high test current...]
Yup, nothing is certain until it's certain.The bottom line would seem to be that if both power and both 0V are not connected no one can tell what might go wrong.
Like not using decoupling capacitors, not wearing a cycling helmet or seatbelt, there is no definitive answer as to what the consequences of doing that will be.
Not really but it seemed to depend on how quickly the upload would complete so may in some way be file size related. When I tested it, small files uploaded easier than bigger files. How big is your JPG file ?PS I've been trying to upload a JPG ... Does anyone have a clue?
I just tried an upload from my Chromebook, 415kb JPG, which uploaded successfully. It appeared that I got a different program at the Picaxe end -- there was a graphic progress bar that went halfway and then stopped for the longest tine, then suddenly disappeared and the file was uploaded. My other computers do not show a progress bar. The file I struggled with is probably smaller. I will try my other machines again with this file that successfully uploaded from the Chromebook.Not really but it seemed to depend on how quickly the upload would complete so may in some way be file size related. When I tested it, small files uploaded easier than bigger files. How big is your JPG file ?
I can confirm that in at least one case, not connecting all the pins leads to the chip not working.has anyone tried running 40x2 with only 1 ground or supply? I ain't messing with my chips...except putting them in the socket the wrong way round.
Connect the supply the wrong way around and it's fried...literally, and the 7805 reg I use was too hot to touch in seconds. There's benefit to using a proper dev board and not birds nest breadboard.I can confirm that in at least one case, not connecting all the pins leads to the chip not working.
Remarkably I just had an 18M2 survive being plugged in the wrong way. I don't suppose it helped prolong its life, but so far, no problem.
Not necessarily with 08M2. I have several times made one briefly very hot by reversing the supply connections, and yet it still seemed to work (so far as I used it). Wouldn't be putting it into any DIY pacemakers, though.Connect the supply the wrong way around and it's fried...literally