I'd like to mess about with the on-board 328 a bit, but I'm having trouble finding the schematic (note the 404 on SF's site). Anyone got one they could point me to? Assuming I can sort some kind of SPI connection to the chip - either with bodge-wires or by some other means - can I burn a bootloader on it using Arduino as ISP, or does it have one already? It seems a bit of a waste to have a whole micro just controlling a display and nothing else, so it'd be kind of cool to have it run some proper programs on it's own.
On the whole I'm less than impressed with this product, will not likely incorporate it into a "real" project, so might as well have some fun with it
I'd like to mess about with the on-board 328 a bit, but I'm having trouble finding the schematic (note the 404 on SF's site). Anyone got one they could point me to? Assuming I can sort some kind of SPI connection to the chip - either with bodge-wires or by some other means - can I burn a bootloader on it using Arduino as ISP, or does it have one already? It seems a bit of a waste to have a whole micro just controlling a display and nothing else, so it'd be kind of cool to have it run some proper programs on it's own.
I hope you brought the 404s to their attention, the files were there previously. I have a few of these displays, so I had downloaded the files some time back, see attached. The SPI and RESET pins are brought out to the pads at the edge of the board, so reprogramming should be straightforward. Looks like it was programmed directly without a bootloader, but I would think one could be burned onto it.
On the whole I'm less than impressed with this product, will not likely incorporate it into a "real" project, so might as well have some fun with it
I tend to agree, although I do find them handy for prototyping. Grumpy_Mike pointed out the lack of current-limiting resistors and that is a concern. As a result, ones are a bit brighter than eights on the display.
I'd like to mess about with the on-board 328 a bit, but I'm having trouble finding the schematic (note the 404 on SF's site). Anyone got one they could point me to? Assuming I can sort some kind of SPI connection to the chip - either with bodge-wires or by some other means - can I burn a bootloader on it using Arduino as ISP, or does it have one already? It seems a bit of a waste to have a whole micro just controlling a display and nothing else, so it'd be kind of cool to have it run some proper programs on it's own.
On the whole I'm less than impressed with this product, will not likely incorporate it into a "real" project, so might as well have some fun with it
For a "serial" 7 segment I had some fun with this product:
Only two digits, but it's a 14 segment and you set the segments via serial like the Sparkfun product. The protocol was a little weird but it was by no means hard. It's basically a shift register in the device. All you have to do is supply 3 lines for enable, clock, and data and then some more lines to select devices if you want more than one (just bus enable and clock to all devices). $2 for 4 digits as opposed to $13.
Graynomad:
Ooo that's sweet, I've not seen them with build-it drivers like that, and alpha numeric as well.
I'm going to get some just because they exist
Rob
Well, it's just a serial shift register. It's not a full blown driver like the MAX7219 or this Sparkfun gadget where you can give it numbers and it displays them. You have to shift in a list of the segments you want on (1) and off (0) so you have to have a little character set in an array for that, but it is not at all hard to make.
so you have to have a little character set in an array for that,
True, but that's really easy (and free) and the thing is $11 or so cheaper than a serial LED like Sparkfun's. For $2 and 4 pins you can have a really simple 4-digit alpha-numeric display for debugging or whatever. You gotta love that.
Actually one strike against these displays is that I cannot find them on any of the normal suppliers, despite LITE-ON being a well-known brand Jameco seem to be the only people stocking these.
So it's either really new or really old, if the second then it's no good for anything really, bummer
EDIT: It doesn't even show up with a search on the LITE-ON site, double bummer.
Thanks for pointing those out! I do frequent the Jameco catalog but had totally missed those! So to run four or six digits or whatever, it would be an SPI-like setup, addressing each pair of digits individually. I'm with Rob, for a buck I might have to get some.
