EDE702 where?

[karenhornby]

I cannot believe you are considering spending money on a part, where a simple PIC (like a 16F628 or similar) for 90p and a dozen lines of PICBASIC code would do the same thing. BTW are you aware that Darrel's taken a parallel LCD (search this forum) and run a near infinite length of wire on it and it still worked? 'A few feet' hardly seems to warrant the effort.

Umm no I didn't know that
What I want to do is mount the LCD remotely but only use a minimum amount of wires if that makes sense, I was thinking about i2c bus but I know nothing about that at the moment, then thought of serial so thought it might be the easiest
However if the length of the wired dont matter then all I really need is 8 wires (including + and -V so it's not as bad as it seems, i was just hoping to use a "standard" type connector like usb with 4 wires and so on.

And you know the best ???

The EDE circuits ARE programmed PICs ...

Grrrrrr.....
what a rip off!
although it is a novel idea, if only I was confident enough to program a chip to do it, but at the moment I've still no idea how serial works lol!

[skimask]

However if the length of the wired dont matter then all I really need is 8 wires (including + and -V so it's not as bad as it seems, i was just hoping to use a "standard" type connector like usb with 4 wires and so on.

Depends on how long of a wire you're talking about. If it's not too long, a standard 3 wire stereo headset extension might do the trick (V+, Grnd, Serial Data) and be cheap. Hook it up, and see how fast it'll go before the data starts to get flakey.
Most off-the-shelf serial LCD modules will only go 'so slow', maybe 2400baud. The slower you send serial, the farther you can send it over a regular chunk of wire. So, if you end up building your own module (which is very very easily done by the way), you could, in theory, make it as slow as you need, or get all sorts of complicated (RS drivers, error correction, the whole ball of wax).

Here's a good start on the whole serial LCD backpack thing:
http://www.picbasic.co.uk/forum/show...erial+backpack

[karenhornby]

if you end up building your own module (which is very very easily done by the way), you could, in theory, make it as slow as you need, or get all sorts of complicated (RS drivers, error correction, the whole ball of wax).

I'll either just use a standard lcd (which I have) and use longer wires and see if it works, or as I'm about to go check the info you suggested I may make my own serial interface (then got to learn how to program/use serial lol)
unless anyone comes up with other ideas.. all welcome
just out of curiousity, how easy is it to use an i2c bus? I see chips on ebay that "aparently" connect direct to a parallel lcd but the input is just i2c ?

[skimask]

I'll either just use a standard lcd (which I have) and use longer wires and see if it works

Probably won't work reliably with any sort of distance between point A and point B.

or as I'm about to go check the info you suggested I may make my own serial interface (then got to learn how to program/use serial lol)

The serial LCD is a piece of cake and the code is right there at that link...some tweaking for your needs and you're in there.

unless anyone comes up with other ideas.. all welcome
just out of curiousity, how easy is it to use an i2c bus? I see chips on ebay that "aparently" connect direct to a parallel lcd but the input is just i2c ?

I2C bus? Not so easy. PBP only 'speaks' I2C Master, not slave, at least not without a lot of effort. An I2C LCD on eBay? Don't think I've seen those yet... Serial...Yes. I2C sounds like more trouble than it's worth.

[karenhornby]

The code is intersting and could easily be "manipulated?" for my needs thanks
The thing I'm struggling with in regards to serial is an actual circuit diagram for a "piggyback board" for the lcd to accept serial output direct from the pic

Forgot to say:
timing's aren't important all it's going to be doing is displaying temperatures from either 2 or 3 ds18B20's
although I'm going to be cheating as such and having each ds18b20 on it's seperate pin as it's too much trouble to try and work out the address of each chip and then how to "talk" to that specific one if they are all on the same pin.
The only problem is obviously it's going to use way more code than nessesary otherwise

[skimask]

The thing I'm struggling with in regards to serial is an actual circuit diagram for a "piggyback board" for the lcd to accept serial output direct from the pic

Nothing special, straight wire for serial from PIC to PIC, maybe an inline 100ohm resistor for protection (no real need for a MAX232 or the like unless you get crazy with distance), straight wires for power and ground...
Past the receiver PIC, it's standard wiring from PIC to LCD.
If you can make a PIC and an LCD work, you can do this easily.
Just try to remember not to shoot yourself in the foot...small steps...get blinky working, get the LCD working, get 2 PICs working, get some serial going between the two, tie it all together.

[karenhornby]

Been looking through old posts, what I'd ideally like to do is "convert?" the LCD module to work as 1wire
The attached circuit looks extremely intersting if it could be made work easily enough (done more research it looks like Melanie, it's one of your circuits?)
now all I have to do is try and figure out how to make shiftout work for an lcd lol

However found this which lookin interesting (circuit taken from one of the posts there) http://www.picbasic.co.uk/forum/showthread.php?t=3981
Post 13

TX side - SEROUT directly replaces LCDOUT (pick your serial transmit format, i.e. baud rate, parity, etc)

RX side - SERIN data feeds byte information directly to LCDOUT (again, pick your serial receive format to math the transmit side)

3 wires - power, ground, serial transmit data

I just dont get how it works.

SEROUT is what your sending from the "main pic" obviously but does that assume you have another pic piggybacked to the lcd directly? and if so how does THAT pic know that what comes in on the serin command equates to lcdout?
if so does anyone have a circuit for this? and any code examples around?