LCD shield and/or LCD serial backpack

Just a question: You do not provide a ground signal to your SPI, SER and I2C connectors. I would have expected these to have a ground since they are not differential. Am I missing something?

Cheater, The 3d view shows the header pins for the LCD and arduino interface on the same side of the board. If I am visualising this correctly, I presume the arduino interface header will be mounted on the opposite side of the board to the LCD header.

Just a question: You do not provide a ground signal to your SPI, SER and I2C connectors. I would have expected these to have a ground since they are not differential. Am I missing something?

Yes your missing the 5V and the GND connector on it. :wink:
The user will have to connect all the grounds together themselves if power and signal are coming from two different sources.

Cheater, The 3d view shows the header pins for the LCD and arduino interface on the same side of the board. If I am visualising this correctly, I presume the arduino interface header will be mounted on the opposite side of the board to the LCD header.

Yep. The 3d view looks pretty but its not perfect.

Btw xSmurf made me add RS232 to the list of interfaces it supports. :slight_smile:
Going to see if I can fit a crystal on it, if not then I'll order.

There was a demo of a LCD shield at the last NYC hack lab.

Well 100 PCBs are now coming to me along with 4,000 capacitors and 5,000 resistors. :slight_smile:
I'll have enough to populate 30 PCBs. The Atmel chips get expensive quicky ($100 for 30).

Around half are earmarked for this first run so about 10 will be for sale. :slight_smile:
If they are popular then I can have another batch ready within about 5 days after that.

There was a demo of a LCD shield at the last NYC hack lab.

Interesting. Got a url?

A shield is great for some things... particuarly "plugging in" lots of connections to something external. However, to add an LCD panel to my Arduino, I only need to tap the serial line and 5v and 0v if I spend $8 for a complete kit of parts (except the panel itself) for the great little LCD panel controller from ModernDevice.com (no "S" in that). It is an implementation of Peter Anderson's #117.

"Except the panel..." The kit lets you interface a wide range of panels to the Arduino. Hence the need to purchase it "separately". ModernDevice offer a selection. Some only $12, if memory serves.

It should even be possible to drive the thing from something other than the serial out pin, but that would entail a little more software work. If you are willing to use the serial pin (and that won't stop you uploading programs to the Arduino) then all you need is.....

setup()
{
serial.start(9600);
}
loop()
{
serial.Print("Hello world");
}

Why reinvent an already available wheel? There are so many other worthy projects waiting out there!!

(My only association with ModernDevice: Happy customer.)

A shield is great for some things... particuarly "plugging in" lots of connections to something external. However, to add an LCD panel to my Arduino, I only need to tap the serial line and 5v and 0v if I spend $8 for a complete kit of parts (except the panel itself) for the great little LCD panel controller from ModernDevice.com (no "S" in that). It is an implementation of Peter Anderson's #117.

"Except the panel..." The kit lets you interface a wide range of panels to the Arduino. Hence the need to purchase it "separately". ModernDevice offer a selection. Some only $12, if memory serves.

It should even be possible to drive the thing from something other than the serial out pin, but that would entail a little more software work.

Why reinvent an already available wheel? There are so many other worthy projects waiting out there!!

(My only association with ModernDevice: Happy customer.)

If TTL serial is the only interface required then the board kit in your link is a dollar cheaper (on the moderndevice.com page its shown as $9 plus shipping). But for some applications (like mine), the hardware serial port is not available (its used for data logging to a PC) and the baud rate (even at 19200) is too slow to use a software uart. For those of us that have real time applications that need something like an i2c interface, a serial only board won't cut it.

But even if my application didn't require the higher prformance, the board being discussed in this thred has greater appeal for me because for the cost of an extra dollar its much more flexible than a serial only board.

Why reinvent an already available wheel? There are so many other worthy projects waiting out there!!

Reasons?
I can list them:

  • Mine is faster and can do more. (ATmega168 vs PIC with 4k flash)
  • Mine is completely open, both hardware and software. The 117 is code protected and no source is provided.
  • Mine has four different interfaces (SPI, I2C, TTL Serial and RS232) compared to only TTL Serial on the 117.
  • Mine is cheaper. $10 for premade and $8 for a kit (SMD components however).
  • Mine is significantly smaller. Under a third of the size of the ModernDevice board.
  • And probably a few other reasons I've forgotten. :slight_smile:

I actually wanted to buy a serial LCD controller but I couldnt find any which were half decent.
They were all closed source and only had TTL Serial and maybe RS232 interfaces.

Also I have a source which sells LCD panels at $7.90 for 16x2 with backlight in single quantities or $5.90 in bulk.
$12 can buy two. :wink:

[EDIT] Oh and if these LCD controllers are popular then I will be going on to tackle things like graphical LCDs and other trickier hardware. [/EDIT]

I thin the other reason is that it is a lot of fun :slight_smile:

The 16x2 LCD board is great and I would also be interested in the Graphics board. I am thinking of using this with "sensor shields", e.g. I want to monitor the depth of a water tank using a pressure sensor.Chris

I thin the other reason is that it is a lot of fun :slight_smile:

Oh of course. :smiley:

Why reinvent an already available wheel? There are so many other worthy projects waiting out there!!

Reasons?
I can list them:

  • Mine is faster and can do more. (ATmega168 vs PIC with 4k flash)
  • Mine is completely open, both hardware and software. The 117 is code protected and no source is provided.
  • Mine has four different interfaces (SPI, I2C, TTL Serial and RS232) compared to only TTL Serial on the 117.
  • Mine is cheaper. $10 for premade and $8 for a kit (SMD components however).
  • Mine is significantly smaller. Under a third of the size of the ModernDevice board.
  • And probably a few other reasons I've forgotten. :slight_smile:

I actually wanted to buy a serial LCD controller but I couldnt find any which were half decent.
They were all closed source and only had TTL Serial and maybe RS232 interfaces.

Also I have a source which sells LCD panels at $7.90 for 16x2 with backlight in single quantities or $5.90 in bulk.
$12 can buy two. :wink:

[EDIT] Oh and if these LCD controllers are popular then I will be going on to tackle things like graphical LCDs and other trickier hardware. [/EDIT]

I'm convinced. I'm currently enjoying my relationship with I2C so I'm keen to see what else I can add to the chain.

So, for 2 units ($20) including 2 16x2 LCD panel's ($12), it's $32 + shipping. Sounds a bit light.

When will they be available off-the-shelf?

Just a question: You do not provide a ground signal to your SPI, SER and I2C connectors. I would have expected these to have a ground since they are not differential. Am I missing something?

Told you Cheats...

Told you Cheats...

Why cant the SPI use the same GND as the power? :-?
There is a GND pin right next to VCC.

Oh they can, that's not the issue. Afaik, the issue is that it's not clear to the user that these lines must be tied together; especially since gnd is already filled.

EDIT: Funny enough, someone just posted this :stuck_out_tongue:

As a rule of thumb, you always need to connect the ground between two devices which talk to each other.

Nick, I'm definitely interested in your OpenLCD project. I started playing around with a 16x2 display last night, starting with the 8 bit interface and then going to 4, and then this morning I was thinking that it should be simple (and cheap) to delegate control to another Arduino chip. Lo and behold, I stumble upon this thread! ;D So, please keep us posted on your progress! I'd love to see some code in the SF SVN repository... (hint, hint! ;))

Ok, so now that I'm thinking about it, is the ATmega168 going to be running the Arduino bootloader (and thus be reprogrammable by other Arduino users) or will it have its own "OS"?

Ok, so now that I'm thinking about it, is the ATmega168 going to be running the Arduino bootloader (and thus be reprogrammable by other Arduino users) or will it have its own "OS"?

It will be a Arduino but the reprogramming feature will be optional.

Basically the EEPROM will store a whole pile of settings.
One of the settings will be if you want the bootloader turned on or not. :slight_smile:

I should get the PCBs early next week hopefully.

Update: The PCBs are on their way and will arrive on Monday.
Now to chase up the components.....

Update: The PCBs are on their way and will arrive on Monday.
Now to chase up the components.....

Sweet! The more I build up my current project (an intervalometer for my camera), the more I realize I need some way to offload the LCD connections somewhere else. I'm using every single pin and I still want to do things like toggle the backlight and add another button or two. Ugh. And I'm already using 4 bit mode, which is noticeably slower than 8 bit!

Cheater will this support the KS0108 graphical LCDs?