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Topic: Needing Display To Do Graphs on Leonardo (Read 797 times) previous topic - next topic

Jul 10, 2013, 07:08 pm Last Edit: Jul 10, 2013, 10:48 pm by mrmonteith Reason: 1
I have a Leonardo and I'm looking for a display that I can do graphs on.   To be large enough to read the labels on the graph etc I'm thinking at least 2.2" or larger.  Preferably closer to 3.2".   Color preferred but monochrome could work too.  I was hoping for something like:
SainSmart Mega2560 R3 + 3.2" TFT Touch LCD SD Card + TFT Shield Kit For Arduino
That or maybe a 128x64 display, if it can do the graphs.
So far I'm getting mixed ideas.  I read somewhere the shields let you use 8-bit of the 16-bit but seems to illude to the fact you can only use part of the display area.  I don't know if that's true in all cases.   In any case it's hard to find what I can use.   I definately don't want to invest in something that won't work of course.

I keep finding things like that but not sure how compatible with the Leonardo it will be?
That or do you have an idea of what combination might work with the Leonardo?

I tried to be as clear on my requirements but I was also up until 3am this morning for work.   I was doing some looking around last night so thought I would ask here and maybe get some directions at least.  If I wasn't clear then maybe I'll get a chance to fill in some details so bare with me.

   Some additional information.   I'm not doing any moving graphics so speed is not a priority.  Also if there is an alernative to using up all the pins that would be preferred. 

  What I'm building is rocket motor test stand.  It will have a cantilever load cell, an instrumentation amp board, and the Arduino Leonardo.   Since rocket motors usually only fire for about 1-3sec I'm going to take the load cell measurements, do some mathmatics and plot the thrust curve on the display.   Along with the curve providing labels of time vs thrust and possibly some calculated results of other parameters.  I'm also looking at saving the data on a SD card or as an alternative hooking it up to the USB to computer and capturing it on the computer.

Michael

Working on instrumentation amplifier for experimental rocketry to measure thrust and chamber pressure.  Could be used where instrumentation

olikraus


You mention "Leonardo" and "Mega2560 R3", which is confusing...

Some of my thoughts:
- The Arduino Leonardo does not have so much of ROM. SD + TFT software will eat up most of the ROM. Not much will be left for your application.
- TFT is slower (more data to be transfered) than monochrome displays (if this is an issue)
- When looking for a display, check the display controller.
- Check, if there is a Arduino Library which supports the display controller
- Do NOT use "controller-less" displays without internal RAM
- KS0108, ST7565, ST7920 are monochrome display controllers which are widely used and have good support for Arduino
- Typical Arduino libraries are: http://henningkarlsen.com/electronics/library.php?id=52 (Color), http://code.google.com/p/glcd-arduino/ (Monochrome, all variants of KS0108 displays), http://code.google.com/p/u8glib/ (ST7565, ST7920 and others)
- Have a look here: http://forum.arduino.cc/index.php?topic=134689.0 (inexpensive monochrome 128x64 display)
- sparkfun.com, adafruit.com and others not only sell displays but also provide (simple) libraries and example projects

Oliver



You mention "Leonardo" and "Mega2560 R3", which is confusing...


The board I have is the Leonardo.  I just realized that one I mentioned came with the Mega2560 too.  So I don't need that part.  Just some of the LCDs mention certain boards but could be used with others.  Which gets confusing too. So really the my question is using the LCD and shield would it work with the Leonardo or not?  

Quote
- The Arduino Leonardo does not have so much of ROM. SD + TFT software will eat up most of the ROM. Not much will be left for your application.

If that's true I have a serious concern over using Arduino without having to go to the Due or 2560 if you can only use one or two devices without running into memory issues.  I'll see how the responses work themselves out.

Quote
- TFT is slower (more data to be transfered) than monochrome displays (if this is an issue)

Definately not an issue as I'm mainly going to create the graph and display it.  So no graphic movement or changes.  Only a single graph.

 Thanks for the information.  I love the Arduino and playing around with it.   So I'm anxious to see how this plays out.  Maybe I'll get some response on the memory usage from someone that's done both.  That and doing some more digging in the forum to see if that information is around too.   Maybe I'll get lucky like I did on the Leonardo and get a Due or 2560 at a good deal.

Thanks so much!
Michael
Working on instrumentation amplifier for experimental rocketry to measure thrust and chamber pressure.  Could be used where instrumentation

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