NHD-4.3CTP-SHIELD-N

[CarlW]

Just starting a project with this shield. I'd prefer to use the Arduino MEGA

Can I ask a few beginner questions?

In the User Guide, the shield is shown plugged into an UNO and also shown plugged into a MEGA.
Assuming the MEGA is not a clone, is it safe to assume no solder jumpers need to be altered for my project to utilize the MEGA?

Any thoughts on getting access to pins (on the MEGA) that are not used by the Newhaven Display?
Would a PCB, pin breakout shield, sandwiched in between the Newhaven Display and the Arduino work?

On the MEGA, are these the only MEGA pins utilized by the Newhaven Display: D4, D8, D9, D10, SPI MISO, SPI SCK, SPI MOSI, 5V and GND?

There is a recommendation in the User Guide to use a 7V to 8V power supply, yet the MEGA allowable input is 7-12V?
Reason for the question is 12V power supplies are widely available.

How much current (from the 5V, MEGA regulator) will be available for my project?
I see the Newhaven shield uses about 400 mA MAX.

Thanks!

[Paul_B]

Thank you for contacting me with this inquiry, I am happy to help clarify how you can prototype with our 4.3" Arduino Shield with Capacitive Touch!

Since you'll probably be connecting other things to the Arduino (LEDs, sensors, servos) you can purchase a breakout shield and sandwich the two together. Another option to purchase an Arduino clone that has the I/O pins brought out on a second connection.

The NHD-4.3CTP-SHIELD-N is compatible with the Arduino MEGA straight out of the box, no solder jumpers need to be configured. By default it will utilize the ICSP/SPI header which is on most genuine Arduino’s.

Finally, our advice is to stick with a 7V - 8V DC adapter since most Arduino's utilize a cheap LDO and have trouble regulating at higher voltages. 

[CarlW]

Still on the topic of this shield.

 

I found an Arduino clone (NERO at Digikey) with a stronger 5V power regulator.
Doesn't get warm, really.

My issue is fitting my sketch into the space on the UNO. My sketch compiled to...
"Sketch uses 24772 bytes (76%) of program storage space. Maximum is 32256 bytes.
Global variables use 912 bytes (44%) of dynamic memory, leaving 1136 bytes for local variables. Maximum is 2048 bytes."
Thought it might work but no. Loads fine but crashes after a few seconds.

I also tried the library example sketch FT_App_Lift.
"Sketch uses 20844 bytes (64%) of program storage space. Maximum is 32256 bytes.
Global variables use 869 bytes (42%) of dynamic memory, leaving 1179 bytes for local variables. Maximum is 2048 bytes."
Doesn't work for me either. Loads fine but crashes after a few seconds.

Surprisingly, library example FT_App_Jackpot works.
"Sketch uses 21434 bytes (66%) of program storage space. Maximum is 32256 bytes.
Global variables use 1159 bytes (56%) of dynamic memory, leaving 889 bytes for local variables. Maximum is 2048 bytes."

All the sketches compile and run fine on the MEGA.

Where can I find a MEGA with a powerful 5V power supply?

Has anyone else had stability issues with library example sketches on an UNO?

[Paul_B]

Hey Carl,

I went ahead and pulled the NHD-4.3CTP-SHIELD-N from stock and powered it with an Arduino UNO clone (NERO) from the lab.

All three sketches have been tested and verified to run properly on the Arduino UNO (see picture attached)


Can you please clarify how you are powering the Arduino UNO clone?

Have you been successful running the "Basics" Arduino examples (Blink.io)?

Thanks!

[CarlW]

Thanks Paul,
FT_App_Lift doesn't work for long on my Nero.

https://youtu.be/oQRlry1Pgak

Arduiono version is 1.8.2

My crash occurs on three different power supplies. USB (computer), 7.5V@0.7A, and 12V@2A (tried all 3)...

The sketch runs fine on a MEGA.

The FT_App_Jackpot sketch runs fine on my Nero.

Blink runs fine on my Nero.

Do you know of any MEGA clones with a "souped" up power supply? I've searched as best as I can, to no avail.

[Paul_B]

Morning Carl,

Very strange, I know this might sound odd but can you please tell me what brand micro SD card you are utilizing?

Regarding the MEGA you can always bypass the LDO by powering the board with a USB wall charger.

At this time I'm not aware of any Energy Efficient Arduino MEGA clones.

[CarlW]

Thanks again, the USB power is a great idea

The SD card says "SanDisk" 2GB.

I bought a handful (used) off eBay just for the shield, as my actual files are under 256K.
Supposedly, these were from cell phones. One never knows about memory cards though.

Might have some larger size ones I could try...