Using ICSP for LCD?

Is it possible to control a LCD module (2x16 liquidCrystal not TFT) from the Yun/Leoardo ICSP as it is happens with the TFT LCD?
Because I've insufficient digital pins for my project and I would like to outsource the LCD...

and I would like to outsource the LCD...

Interesting choice of words. I've never seen that expression used to describe trying to control an lcd from the ICSP connector.

Here's some questions you should ask yourself:

  1. Is it a parallel (4-bit) lcd or is it I2C ?
  2. If it is parallel, how many pins do I need for a parallel lcd ? (Are any of those pins on the ICSP connector ?)
  3. It it is I2C, does the ICSP connector have A4 & A5 on it?
    After you have answered those to your satisfaction you might ask yourself:
  4. Do I have any other options besides the ICSP connector ? (ie: parallel to I2C backpack) like this one:
    http://www.ebay.com.au/itm/New-IIC-I2C-TWI-SPI-Serial-Interface-Board-Module-Port-For-2004-1602-LCD-Display-
    /261176654807?pt=LH_DefaultDomain_0&hash=item3ccf577bd7&_uhb=1

If so, maybe this post would be helpful:
http://forum.arduino.cc/index.php?topic=210349.15
5. Last but certainly not least ; What communication protocol employs the ICSP connector ?
FREE Answer !: SPI
See this:

Pins required for SPI:
SCK
MISO
MOSI
SS- (ussually 10, but redefinable)-(NOT ON ICSP connector)
6. That raises the question "Are there any SPI lcds available for an arduino/YUN ?

Is it possible to control a LCD module (2x16 liquidCrystal not TFT) from the Yun/Leoardo ICSP as it is happens with the TFT LCD?

(one might wonder if that is the same question as #6 ?)

https://www.google.com/search?q=SPI+LCD+ARDUINO&rlz=1C1GPCK_enUS504US504&oq=SPI+LCD+ARDUINO&aqs=chrome..69i57j69i65l3j69i60l2.5184j0j8&sourceid=chrome&espv=210&es_sm=93&ie=UTF-8

  1. Which brings us another question: Since SPI is a multidevice protocol, requiring only the three spi signals plus a chip select (SS),
    which is redefinable, isn't it possible to run as many SPI lcds as you have chip select pins to support ?

Hi raschemmel,
even though I've only understood half of what you've written, I think It's now clear that my LCD isn't SPI and won't work on ICSP.
But anyway, thanks for your detailed reply :slight_smile:

Is it possible to control a LCD module (2x16 liquidCrystal not TFT) from the Yun/Leoardo ICSP as it is happens with the TFT LCD?

Not easily if those are the only available pins since only three of the six ICSP pins are I/O pins.

Possible solutions are:
(1) You could buy or build a conventional serial adapter and use a 'software serial' interface on two of those three I/O lines.

(2) You could buy or build an I2C adapter and 'bit-bang' an I2C interface on those three I/O lines to run your LCD.

(3) Those three I/O pins are also the SPI pins. You could buy or build an SPI adapter for your LCD but you would need one more I/O line for the SPI chip select.

(4) You could use those three I/O lines along with three more to run your LCD using the LiquidCrystal library.

Don

I think It's now clear that my LCD isn't SPI and won't work on ICSP.

I think what may NOT be clear to YOU is that the function of a backpack is to provide a plug & play adaptor into which you can plug a regular 16 pin 1602 parallel lcd (that has a male to male header attached) into and use as either an I2C OR SPI, depending on the particular adaptor. Most of the I2C backpacks are NOT also SPI. You need to understand (from my first reply) that regardless of the SPI device, the chip select (SS SPI signal) is NOT on the ICSP connector and while it is usually pin 10 it does not have to be because the SPI chip select is always redefinable because you only have one pin 10 and SPI is designed for multiple devices so you will always wind up using pin-10 + pin-x,pin-y,pin-z etc... for your chip select pins.

  1. Do I have any other options besides the ICSP connector ? (ie: parallel to I2C backpack like this one:)

(addresses are configured with solder pads)
FYI: I2C only requires A4 & A5 , because it is address based, not chip select based. The above backpack can be used for
up to eight lcds.

I think It's now clear that my LCD isn't SPI and won't work on ICSP.

Very few (if any) of the LCD modules commonly available to the hobby market run directly on SPI. There are SPI adapters available and there may be links to one of them buried somewhere in reply #1.

The one that I have is available from SpikenzieLabs (I2C-SPI_LCD). Scroll down for the SPI info. The same module is used for either I2C or SPI but a different chip is used for each mode.

Don

This LCD is I2C/SPI , SWITCH SELECTABLE , TWO CONNECTORS (ONE I2C, ONE SPI)

I have bought from this vendor and they are reliable.

This LCD is I2C/SPI , SWITCH SELECTABLE , TWO CONNECTORS (ONE I2C, ONE SPI)

Not exactly. That is a standard, run-of-the-mill, everyday, ordinary, parallel LCD that comes with an I2C/SPI adapter already attached.

Edit: Although unrelated to this thread what may be more important to some is that it looks like that particular I2C/SPI adapter also has holes to accommodate those LCD modules with two rows of pins located at the end of the module.

Don

Yeah, you know that's what I meant.

Although unrelated to this thread what may be more important to some is that it looks like that particular I2C/SPI adapter also has holes to accommodate those LCD modules with two rows of pins located at the end of the module.

It's called IDE, (16-pin IDE in this case)

Definition: Abbreviated IDE, it is a standard type of connection for storage devices in a PC. Generally, it refers to the types of cables and ports used to connect some hard drives and optical drives to each other and to the motherboard.
Some popular IDE implementations that you may come across in PCs are Parallel ATA (PATA) and Serial ATA (SATA).

It's called IDE, (16-pin IDE in this case)

Please tell me that you are kidding.

Don

Yeah, you know that's what I meant.

Not really. It appeared to me that you meant to provide an example of a readily available SPI LCD to refute my statement that "Very few (if any) of the LCD modules commonly available to the hobby market run directly on SPI".

Don

Please tell me that you are kidding.

No I'm not. If you are ordering dual male-male header's, (like the one you are referring to, that is what you ask for. The vendor
doesn't care that it has nothing to do with PC's or hard drives, that is the common term for that kind of dual header, period.
It's a type of connector, that's all. I'm not going to get into whether or not that is an official nomenclature. I am just saying
that if you tell someone the lcd has a male IDE-16 connector or header, anyone with experience knows what you are talking
about.

https://www.google.com/search?q=16+pin+idc+male+connector&tbm=isch&tbo=u&source=univ&sa=X&ei=8GQOU_DoAYewoQTlq4GADQ&ved=0CFQQsAQ&biw=1309&bih=807

The vendor doesn't care that it has nothing to do with PC's or hard drives, that is the common term for that kind of dual header, period.

Maybe you should check out IDC instead of IDE.

In my experience if I wanted to connect a cable to an LCD having two rows of holes at the end I would probably have more luck using a flat cable with IDCs (Insulation Displacement Connectors) rather than I would with an IDE (Integrated Drive Electronics) cable.

Most of my old IDE cables have the wrong number of wires whereas I can find IDC connectors with the correct number of pins and strip off enough wires from a flat cable to leave the correct number for the connector.

Don

My mistake. That's what I meant to say but since IDE cables use IDC connectors I got the two mixed up.

raschemmel:
The vendor doesn't care that it has nothing to do with PC's or hard drives, that is the common term for that kind of dual header, period. It's a type of connector, that's all. I'm not going to get into whether or not that is an official nomenclature. I am just saying that if you tell someone the LCD has a male IDE-16 connector or header, anyone with experience knows what you are talking about.

Before you clarified the matter of "IDC", I was about to observe that the relationship was actually inverse - only those without experience would be using such a colloquial expression while - as here - someone knowing exactly what they are talking about finds it quite confusing. :smiley:

Not unlike the common mis-reference to "DB-9 connectors" and "DB-15 connectors".

Yes , you're right. Saying "IDE" when you really mean "IDC" means you have no experience or it has been so long since the last time you ordered either one that you forgot the difference. XD The fact that almost all IDE cables have IDC connectors couldn't have anything to do with it.

Part of the problem may be that you quoted an incorrect definition of the term IDE without investigating the validity of that definition..

The 'E' in 'IDE' stands for electronics and IDE refers to electronics that are integrated with a drive as opposed to being in some other location such as on a motherboard.

By the way the term IDC connector is just as redundant as the term ATM machine.

Don

From Reply #4

Most of the I2C backpacks are NOT also SPI.

From Reply #5

Very few (if any) of the LCD modules commonly available to the hobby market run directly on SPI.

From Reply #10

It appeared to me that you meant to provide an example of a readily available SPI LCD to refute my statement that "Very few (if any) of the LCD modules commonly available to the hobby market run directly on SPI".

I would say that I said it first but because I used the word "backpacks" and you used the word "modules" , you would surely claim I was incorrect. You and I both know what we are talking about. We have been discussing these lcds and backpacks for months now and you know that I know that you know that very few of the the backpacks (OR MODULES for that matter) run on SPI, but when I said some "lcd" was both I2C OR SPI you corrected me that it was the backpack that was dual personality
and not the lcd.

IDE/IDC ? (six of one, half a dozen of the other) , their usage is so intertwined that they are almost synonomous.

That's news to me. They say you learn something every day, but I guess a lot of what is learned is incorrect.

Don