Matrix Orbital Corp

I split up the different Arduino targets into several in EVE_target.h as things really got comlicated with specialised code.
And at the end there is a generic Arduino target that I never compile for which was missing Chip-Select set and clear functions.

That should be fixed now.

Thanks Rudolph! Compiles now.

Hello Lads and Gents,

actually i'm facing some issues with the display and/or the code i actually cannot solve by myself.
I hope you guys can give me an idea what im doing wrong.

I connected the pinout to an atmega328p(Arduino nano) and using the FT800-FT813-5.x - arduino example.
i get the display initialized ( i guess) but cannot be 100% sure because i have no acess to console connection due to the fact that the only way to connect would be usb and the signal levels rising to 5v. actually i have no levelshifter onsite to implement a protection for the display.

But maybe some of you allready seen this before and may have an idea.

Display initialised randomly in different ways. the most common image you can see below. the lines are flickering and image dont change.
after a while the display switches to a black solid background (not all the times and everytime in different time frames)
or to the image below
anyone any idea? :(
thanks a lot in advance!

best regards
eschmo

EDIT: it is a EVE3-70G

Have you edited EVE_config.h to compile for the EVE3-70G?

#define EVE_EVE3_70G

The one online has this active now:
#define EVE_RiTFT50

These are rather similar in that both have a BT815 and 800x480 but they use different display timings
and the EVE3-70G is using a GT911 touch controller.

If you have edited EVE_config.h, my next guess is that this is a power supply issue.
You need a little more juice on the 3.3V.
Roundabout 150mA for the logic including the panel and 500mA for the backlight so the 3.3V supply
should be good for at least 700mA.

And if it is not the supply either there is a problem in the wiring.

While the pinout is a bit odd on the NANO with D13/SCK not next to D12/MISO and D11/MOSI, the pins are all the same.
My example compiles for Arduino / __AVR__ so a target added to platform.ini like this:

[env:nano328]
platform = atmelavr
board = nanoatmega328
framework = arduino

compiles the same code as the existing [env:uno] or [env:avr_pro] configurations.

Please provide a precise schematic on how exactly you wired it all together.

Hello Rudolph,

thanks for your support!

First of All, i power up the circuit with two LF33ABV and these supply the cuircuit with a total of 1A.
My switching power supply shows a load between 0.33 and 0.65 A. So the totals should be okay.

i've defined
as well.

I've connected
SCK -> D13
MISO -> D12
MOSI -> D11
CS -> D9
RST -> D8

In total no pull-ups or pull-downs used for the bus connections.
testing with pull downs at CS and RST didnt show any effect.

Oscilloscope test at channels.
RST is allways high when 328p is on and just drops when 328p is reset.
CS ~250Hz and rect signal.
MISO ~2,3kHz
MOSI ~14.6kHz
SCK ~92kHz

I'am compiling with Arduino IDE, what did you use? Maybe this is the problem?

best regards
eschmo

eschmo wrote: Wed Feb 03, 2021 1:41 am First of All, i power up the circuit with two LF33ABV and these supply the cuircuit with a total of 1A.
My switching power supply shows a load between 0.33 and 0.65 A. So the totals should be okay.

Do you use these two linear regulators in parallel?
That might not be a good idea as these always have different voltages at the output.

Using them separately, a single one for the backlight and annother one for the logic might work but first there is a resistor on the display PCB that connects 3V3 with BL_VDD and this would need to be removed and without the proper tools I would not advise doing that.
But even then I would use a regulator with a higher current rating for the backlight.

Well, you have the backlight starting but it is possible that a voltage drop from switching the backlight on is crashing the BT815.

eschmo wrote: Wed Feb 03, 2021 1:41 am I've connected
SCK -> D13
MISO -> D12
MOSI -> D11
CS -> D9
RST -> D8

In total no pull-ups or pull-downs used for the bus connections.
testing with pull downs at CS and RST didnt show any effect.

This looks okay.
Pullups or Pulldowns in the CS and PD lines are not really required but provide a defined voltage level while the attached controller is held
in reset, for example at power-up or when re-programming.

eschmo wrote: Wed Feb 03, 2021 1:41 am Oscilloscope test at channels.
RST is allways high when 328p is on and just drops when 328p is reset.
CS ~250Hz and rect signal.
MISO ~2,3kHz
MOSI ~14.6kHz
SCK ~92kHz

RST is okay, the two functions to set/clear it are only used in EVE_init() and only called once.
But for the rest of the signals I hope that you did not measure these correctly. :-)
CS should be mostly high with very short low levels every 5ms and about 0.6ms low every 20ms.

SCK should be at 8MHz.

Hmm, now that I think about this.
The Nano is supposed to be working with 5V and you are using it with 3.3V, correct?
Technically this is out of spec for the AVR but the Seeduinos I have here have the AVR running just fine
with 3.3V and a 16MHz crystal.

eschmo wrote: Wed Feb 03, 2021 1:41 am I'am compiling with Arduino IDE, what did you use? Maybe this is the problem?

I am using the PlatformIO plugin for VSCode.
But I just opened the src.ino in Arduino IDE 1.8.13, selected the board "Arduino Nano" and it compiled just fine without any warning.
9318 bytes FLASH, 79 bytes SRAM

To be able to open this with the Arduino IDE is the only reason for the rather strange name "src.ino", PlatformIO needs the directory to be named "src" and the Arduino IDE needs the main file to be named the same as the directory it sits in, because of reasons.

eschmo, please try this:

https://github.com/MatrixOrbital/Basic-EVE-Demo