t90add

Screen

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Hello, I was wondering if anybody has a means of attaching a LCD screen onto the papilio where we could graph inputs from the adc? It was a pretty simple process to do on arduino. 

 

 

Thanks

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Yeah I saw that earlier, I was wondering if we could get it working without a soft processor. Is it possible to run multiple soft processor on the papilio, i.e. so that we can have parallel operations running?  

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Running multiple Soft Processors: As long as they fit the device, I don't see why not.

 

Now, that is not multiprocessing nor it is multicore. Those are way more complex. But you can have several designs.

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It would be possible to run multiple soft processors, but I think maybe a better approach is to make a VHDL Wishbone peripheral for those LCD devices. Then the Wishbone peripheral works in parallel and does all of the heavy lifting and the soft processor just sends very minimal control commands.

 

In fact, Alvie is already working on a HDMI/VGA controller, it would probably be very easy to make it a HDMI/VGA/TFT LCD controller. We are already targeting the adafruit GFX library to provide the API to interface with the controller...

 

Jack.

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Well, Wishbone peripherals are defined in the FPGA using VHDL or Verilog...

 

But there is no reason we can't make an arduino mini to wishbone bridge that would let you use the arduino mini instead of a soft processor. In fact, I'm designing a board like that right now, but we use the Arduino Leonardo instead.

 

Jack.

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Well, it is possible to wire up a cheap LCD display from ebay and use it with the adafruit gfx library...

http://www.gadgetfactory.net/2011/10/experimentation-with-tft-touchscreens/

 

It's on my list of things to do to complete the Wing to connect these displays, but other things keep taking precedence.

 

Jack.

Is there anyway to use this lcd display? 

 

http://www.soselectronic.hu/a_info/resource/c/4Dsystem/uLCD-144-G2GFX-DS-rev1.pdf

 

I've used it with arduino/chipkits before. 

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I purchased mine from: https://www.sparkfun.com/products/11377, unfortunately they are out of stock at the moment (supposedly until Feb-19). 

 

These guys have some in stock http://www.robotshop.com/en/4d-systems-serial-lcd-tft-display-module.html?utm_source=google&utm_medium=base&utm_campaign=GoogleUSA

 

 

Edit: Here is a cheaper alternative http://microcontrollershop.com/product_info.php?products_id=4058&gclid=CMGvub6us7wCFZDm7AodxnUAqA. 

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Actually, the more I read about this display the more excited I am for it to arrive. :)

 

I didn't realize it has a GUI Designer application, I've been looking for just such a thing to use with the Papilio. I think people want to be able to draw up GUI's on their computer and control them from the Papilio.

 

Jack.

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Yup, the Goldelox processor is pretty powerful. Have you purchased a "4D systems programmer"? It allows you to make the embedded processor(i.e. Goldelox) either a master or slave(i.e. a screen that takes the .gfx commands from another microprocessor like an arduino for example or Papilio presumably). Actually now that I think about it, I think you need the programmer to program the tft screen with "Workshop"...? 

 

 

 

Edit: Links

 

Programmer: http://www.4dsystems.com.au/product/17/114/Accessories/4D_Programming_Cable/

 

Workshop IDE: http://www.4dsystems.com.au/product/10/120/Development/4D_Workshop_4_IDE/

 

Demos: https://mbed.org/users/4180_1/notebook/ulcd-144-g2-128-by-128-color-lcd/

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Update:

 

So I emailed support (of 4d systems), they said it is possible.

Essentially:

 

1) I will need to stream out a register data

2) The screen will need to buffer the register data being streamed from the FPGA, and use the Spectrum widget (or Scope widget) to simulate the graph using ViSi Environment of workshop (since I want to plot the values from the ADC of the papilio)

3) On the FPGA, I will need to model a circuit for the ADC register and UART (making sure that the baud rates of papilio and the screen are equal). 

 

 

Edit: I'm not completely sure on how to do any of this  :(

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It will be easy, let me get mine and I'll help.

 

I would recommend that you look at the examples for interfacing with the Analog Wing in the new release of the ZAP IDE. How were you planning to get the ADC data again?

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Well I was thinking that I would just use the Retrocade Megawing's ADCs, where I would take two signals. I would store these 2 signals into one array (with some size C). I would then send this array after some clock period to the TX which would connect to the RX of the LCD Screen. Then on the LCD screen I would plot both signals concurrently. I think.  

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Ok, the RetroCade MegaWing will work. My big concern was having free pins to connect the display. You will be able to use the Wing Header on the RetroCade to manually wire up the LCD.

 

The RetroCade's ADC are 8 bit though, so you will only get an ADC reading between 0-255.

 

The Analog Wing has better resolution at 12 bits, you get ADC readings between 0-4095.

 

Jack.

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Well, I got the display but unfortunately the cheaper one is just the screen with a flex connector. I don't feel like messing around with wiring up miniature wires to the flex cable so I had to order another one with the PCB included. Going to be another wait for it to arrive.

 

Jack.

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That's fine. I'm trying to get used to the Schematic editor. Essentially I would need to incorporate one serial wishbone, then use it to tx data to the display's rx? 

 

 

Thanks

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Yes, you need one serial wishbone device, and you need to connect rx from the wishbone device to tx of the display and tx from the wishbone device to rx of the display. So there should be two connections and they cross.

 

Jack.

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