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Topic: H35B touch screen (Read 1 time) previous topic - next topic

rotorway133

Hello.  Bought this touch screen for Arduino. ( attachments pictures)  I cant find ANY test sketches or any info at all how to make it work. Best I get is a light blue screen :( Anybody tried this ? Pretty new at Arduino ( I'm not bad but no big expert)

BJHenry

Can you share a link to where you bought it from please?

hydrastarmaster

#2
Oct 23, 2019, 02:57 am Last Edit: Oct 23, 2019, 03:10 am by hydrastarmaster
Hi.
I got the same touch-screen just a week ago. After some PR with China, I finally managed to make it work.
As far as I know, currently this is the first post to present the whole solution, so... let me write the story.

H35B-IC is a capacitive touch screen used in the production of embedded system. It's one step ahead, but still under development. The board i got is a v. 3.8. In this version, a SD card connector has appeared, but it's not yet implemented.

Night 1: I bought the screen, that had to come with IDE and manuals... but there were no manuals, no sw, no specs. On the manufacturer site there are only manuals and old sw scraps. Panic.

Night 2: After a night spent drawning in Chinese manuals, I wrote to the manufacturer, that gave me a "secret" link to download the sw (let's call it v. 1.2, y2019). Wow. Tried it, something append... but Chinese manuals were tricky. Ok. Got to load the internal memory [4 pin port: just to load the memory thru the included CH340 serial key]. Screen working and operative. Connected the H35 to Arduino, tried to load the sketch (included in V. 1.2): doesn't work, no way, neither compiled. They seems to be under-development sketches, on the way to integrate usual graphics functions.

Night 3: I complained with the seller for the lack of manuals and sw. He (from China) gave me a link to a somewhere hosted package (let's call it v. 1.1.1.0, y2017). Inside it, I found the English manuals, IDE v. 1.1.1.0, Arduino I2C libraries and examples. Great. Arduino loaded and operative (using the demo project included). IDE v. 1.1.1.0 is an old version, uses different file formats, and it's a sort of pre-alpha, that cannot create a new project. I saw on 1 forum that a guy got his hands on v. 1.1.1.0, and was obviously unable to proceed.

Solution and toolchain:
I've merged and filtered the two packages. Sorry but the zip doesn't fit to be attached here. You can open a temporary mail and I can send you the sw. I can respond for a few times, not forever, so you'd better takes the time to load it to a common repository. Thank you for understanding.
  • CH340 drivers (not tested by me: I already had it installed from elsewhere).
  • English manuals & datasheets (please give a look at 'em all).
  • Utility to get the RGB565 codes (just in case of need, but it's a plus).
  • VLcd IDE, with demo project to load in H35 memory from the 4pins port. The IDE is fully functional and self sufficient to work.
  • Arduino libraries, with an example sketch that go together with the demo project. H35 connects to Arduino thru the 6pins port.

Something more to know:
  • The screens ("pages") have to be compiled before being loaded to the screen. Compiler messages are not always so friendly, so you'd better take the habit to put the hands directly on the xml artifacts that describe the pages.
  • The serial comm inside the IDE shall work only thru a serial/I2C converter... for us that's to say a sketch that is not available in the packages, or a physical interface. So if you try to test and it doesn't respond, you know why.
  • The stuff is very nice, because the screen works in parallel to the MPU, and communicates by interrupt. So the MPU is free to do its job in the meanwhile.

To do (for development):
  • For the manufacturer has not yet implemented the usual low level graphic functions, we have to test if it works with some other available libraries. Development can be done more easily getting a look at the messages from within the internal debugger interface.
  • It would be appropriate to realize or find a sketch to use the debugger directly from Arduino.


Enjoy your touch-screen.  :smiley-cool:

nikthefix

I have 2 of these units - i2c and uart versions. The hardware is high quality with a TFT that appears almost IPS - great blacks and rich colours with very good off axis viewing. Much nicer looking than my Nextion displays.

The capacitive touch is superb.
Screen updated are fast with no tearing or flickering.

The visual designer is hard to find but but I got a copy by emailing the aliexpress vendor. It works but is far from 'ready'. New projects cannot be created (version 1.1) so the demo project must be copied, edited, saved. Not a problem. No other restrictions. The interface is like Nextion but the feature set is limited at present. Forget the widgets and just use your own bitmaps and defined touch hotspots.

Utilities are provided by hundatech for converting and uploading images and the API for i2c / uart control is documented.

If you need a cap touch and cheap hmi then I recommend trying this. The 7" cap touch nextion is too expensive IMO - especially when you consider that you can get a STM32 discovery board like STM32H750B-DK for £70 and use the free TouchGFX editor. Here's what it can do:

https://www.youtube.com/watch?v=hBLhz76p4-I


simonrafferty

I doubt this link will stay live forever - but this is what the vendor sent me:
https://www.adrive.com/public/gtyuYs/0128058%202.8%203.5%204.3%205inch%20display%20%20i2c_package_english_v1.2.zip

If the link vanishes, PM me and I can probably mail you a copy

oldbinaryguy

#5
Jun 25, 2020, 08:35 pm Last Edit: Jun 25, 2020, 09:00 pm by oldbinaryguy
I recently got the 3.5" version of this tft .. well build ..nice looking ..  downloaded material from the link you provided .. demo code up and running ..

does anybody know if you can draw on the screen directly through the library? .. I need to run a 1024 bit FFT

which is producing 512 data points .. and I have no idea how to integrate it with the waveform feature..
actually I was going to graph every second point as the 512 points are larger then my screen resolution.

are there any low level graphics functions available ? I'm struggling just to identify the onboard processor..

I'm seriously considering switching to an ra8875 based tft with spi ...

any input would be welcome....

Thanks

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