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Driving 2X RA8875 off of one microcontroller, can it be done
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Re: Driving 2X RA8875 off of one microcontroller, can it be

by eph_raim on Tue Oct 06, 2015 6:04 pm

i just want to input texxt from keyboar to arduino to the ra 8875.. just like the process of using 16x2 lcd ..the display of the ra8875 will only be displayin text that i inputted using keyboard

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Re: Driving 2X RA8875 off of one microcontroller, can it be

by eph_raim on Tue Oct 06, 2015 6:18 pm

Pin
3~ sclk ps2keyboard
4~ data ps2keyboard

from the keyboard i want to display the text on ra 8875 that uses
pin
9~Cs
10~Rst
11~miso
12~mosi
13~sck
with these how can i display the text inputted to the keyboard to the ra 8875

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Re: Driving 2X RA8875 off of one microcontroller, can it be

by paulstoffregen on Tue Oct 06, 2015 6:25 pm

Why are you asking for generic advise to program Arduino on this old thread specifically about using 2+ of these displays? You're not even using 2 of them, are you?

Arduino is a tool, much like a hammer. You can use it to build all sorts of things. But you do have to learn and work. Just like a hammer, if you want someone else to do all the work for you, there are plenty of carpenters and craftspeople in the world you can hire. You wouldn't expect someone at a hardware store to build your house with the hammer they sell, would you? They might give you some advise, and as far as support goes, Adafruit is great about helping you to figure out how to use these wonderful tools. But *you* must actually do the work. You can't expect Adafruit or me or anyone else you're not hiring to do it all for you!

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Re: Driving 2X RA8875 off of one microcontroller, can it be

by eph_raim on Tue Oct 06, 2015 6:33 pm

Im using two of this dsplays. Using two ra8875.. im just asking how can i peroform such thing.. im not forcing you to answer my questions directly i just want you to help me and suggest what to do.. thats all.. if you dont want to help well thats ok with me.. by the way.. thankyou. im just new with this things thats why im asking for help .

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Re: Driving 2X RA8875 off of one microcontroller, can it be

by adafruit_support_rick on Tue Oct 06, 2015 10:16 pm

You want to use the PJRC PS2 Keyboard library to read the keyboard:
http://www.pjrc.com/teensy/td_libs_PS2Keyboard.html

Have a look at the textmode example in the Adafruit RA8875 library to see how to write text to the screen:
https://github.com/adafruit/Adafruit_RA8875

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Re: Driving 2X RA8875 off of one microcontroller, can it be

by eph_raim on Tue Oct 06, 2015 10:32 pm

Thankyo adafruit_rick

Ill check on that .. your answer is highly appreciated...

Thankyou very much

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Re: Driving 2X RA8875 off of one microcontroller, can it be

by buzzb on Thu Jan 07, 2016 3:20 pm

paulstoffregen wrote:The problem appears to be hardware, that the RA8875 chip does not tri-state its MISO pin when CS is high.


Paul (or anyone else who might be able to answer ;-),

I'm teaching myself electronics, but I am not a complete beginner. I'm always on the lookout for things to learn. So...

How did you come to this conclusion? By pouring over the datasheet? Intuition? Trial and error? Or... was there some way to measure (multimeter or scope) to see that the MISO pin wasn't tri-state?

I'm working on a project at the moment where I intend to connect a punch of sensors on the SPI bus, and I figure I will probably have some debugging to do along these lines at some point.

Thanks,
Buzz

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Re: Driving 2X RA8875 off of one microcontroller, can it be

by riadanza on Fri Jan 08, 2016 12:10 am

I was able to have the display, cc3000 and SD card all work perfectly by wiring in the chip and adding the pull down resistors, this thread was a big help, thanks.
Last edited by riadanza on Wed Apr 27, 2016 12:12 pm, edited 1 time in total.

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Re: Driving 2X RA8875 off of one microcontroller, can it be

by Sierra on Wed Apr 27, 2016 12:03 pm

Gentlemen,
I am fairly experienced with logic device programming but new to the uC world so please help me as I learn.

As part of a test rig I would like to build a 2 display unit. Great advice so far and I am following along with this very useful and informative thread.

I am somewhat disappointed to see that even the latest version of the RA8875 I purchased - presumably brand new production - still has the tri-state problem but I suppose economics rules.

My question is more basic. I wish to use a Feather MO as the uC. Will this need a new library? I was rather hoping that since comms. went through SPI that the commands would use a standardised instruction set and library. Do I need a new library or should an established one work. I presently have the latest RA8875 library but this results in a blank screen with a single display.
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Re: Driving 2X RA8875 off of one microcontroller, can it be

by adafruit_support_rick on Wed Apr 27, 2016 7:36 pm

We haven't tested the RA8875 with an M0. Looks like the library may need some tweaking. I'll look into it.

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Re: Driving 2X RA8875 off of one microcontroller, can it be

by Sierra on Thu Apr 28, 2016 12:06 am

Thanks Rick,
I started using a Zero recently then I figured the Feather MO would be the perfect portable companion. The recharging system is a great idea.
Look forward to getting you RA8875 and 5 inch display working.
The final portable system needs two displays but I may just build two separate systems instead of one Feather with two displays.
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Re: Driving 2X RA8875 off of one microcontroller, can it be

by adafruit_support_rick on Fri Apr 29, 2016 4:52 pm

Looks like a bit of a job. I'll work on it as time permits.

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Re: Driving 2X RA8875 off of one microcontroller, can it be

by adafruit_support_rick on Sun May 01, 2016 1:35 pm

Works. Get the latest version of the RA8875 library.

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Re: Driving 2X RA8875 off of one microcontroller, can it be

by Sierra on Sun May 01, 2016 2:17 pm

"Miracles we can do quickly, the impossible may take a little longer"

Thank you very much, I will try it right now.
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Re: Driving 2X RA8875 off of one microcontroller, can it be

by Sierra on Sun May 01, 2016 3:51 pm

Rick,
Wiring the Feather MO to the RA8875 board was simple, only a little connection swapping.
"Buildtest" working fine so I am transferring the test display that I had on the basic character LCD to the TFT.
Pleased to see that the RA8875 board works well on the 3v3 power supply from the MO.

Thank you very much for your prompt help.
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Please be positive and constructive with your questions and comments.