The ili9468 boards seem to be very common and inexpensive, but I'm windering how they connect to a Uno? They're a shield form factor, and the 'pinout' is shown at for eg
But, there seems to be too many pins for a Uno, and finding a listing of the pins actually used is really difficult.
Ideally I'd like the Uno to have enough pins left over to drive an IR emitter, or possibly an ESP board. I'd prefer the parallel shield, having used a few SPI displays they're kinda slow.
Is this going to work for me? I've never actually hooked up an ESP to another MCU, always just usaed them standalone so not sure what they want to drive them.
The ebay link takes me to a site where the heading texts says " 5V TFT LCD Touch Screen Display Module 480X320 for Mega 2560 Board 3.5"
while the picture shows a shield that fits an Uno. This is an Uno shield! It will do its job when properly mounted on an Uno.
Here is a screen capture of that shield on that website:
There is no controller called ILI9468. Ilitek make a chip called ILI9486
Any shop that perpetuates the typo error does not inspire confidence.
The pcb does not contain a voltage regulator. The TFT backlight draws current from the 3.3V pin.
Whereas the smaller 2.4 inch screens exceed the 3.3V current by a small margin, this 3.5 inch screen will damage the wimpy 3.3V regulator on Uno or Mega2560. Zero, Due, STM32, ... have beefier 3.3V regulators.
So I would never advise this pcb for a Uno or Mega2560.
However it will "work".
You need 2-9, A0-A4 for operating TFT and Touch.
Which leaves 10-13, A5 for external electronics (if you don't use the microSD)
The LCD pins are clearly marked on the Shield. The sockets are clearly marked on the Arduino.
Thanks for the replies. There's a lot more to it than I'd thought. The boards using the ILI9486 chip seem to have either Uno type pins, or the dual inline Mega style, and I was assuming the former (yep, I deserve worse than kindly replies on a forum) that they plugged into a Mega with no problems, apart from lackage of IO pins.
TBH honest I'd rather just use an ESP32, if I could find a display that won't have issues with the largish images I want on the display (so, 480x320, not that much of an ask, with some bitmaps drawn on top) so I should really have asked the right question: what is a good solution for driving a mid sized display at reasonble refresh (not motion video, but not 2 seconds to refresh) and WiFi, IR and possibly a button or 2. SD card would be nice.
The current use issue is overiding though. I imagine a separate 3V3 source would fix that, but honestly.. it's not fit for purpose if it blows a regulator.
I imagine people who have worked in EE for some time look at this with some feeling akin to training a 3 year old, but I'm very grateful for the time.
I would think that Uno format shields and Mega2560 format shields were self explanatory.
"Spare" GPIO pins are pretty obvious too.
ESP8266 has 0% chance of driving any Parallel display.
ESP32 can drive 8080-8 Parallel but not many spare pins.
Uno can drive 8080-8 Parallel but not many spare pins.
Zero can drive 8080-8 Parallel but not many spare pins.
Mega2560 or Due can drive 8080-16 Parallel and have plenty of spare pins.
They can all drive SPI displays.
All display controllers are 3.3V devices
Obviously 5V Uno, Mega2560, ... require level shifters for every signal.
If you wanted to use ESP32 in the first place you should have said so.
320x480 Red SPI displays with ST7796S controller work very well on ESP32 e.g. with TFT_eSPI library.
It does seem to me that the Uno and Mega share a subset of pins, that is, a Uno shield will line up on a Mega with corresponding pin function, while leaving the extra pins a Mega offers free from the shield blocking them. This may have been done purposely.
A bit of a look at a Uno datasheet says the 5V pin is good for 400mA - 900mA depending on whether it's supplied from USB or its power socket. The 3V3 line is good for 150mA. If these shields exploded MCUs becuase they want 3V3 logic I do think someone would have noticed. Then again, public advice can be filled with misinformation.
Yes, I should have made my original post with more consideration. All I want is a device with a touchscreen LCD that is somewhat responsive ie doesn't take seconds to refresht the screen, is reasonable large and high density pixels so 480*320 min, and be able to use WiFi and maybe IR as well using whatever MCU is required. My experiences with SPI displays are forgetable, taking a long time to refresh even on a tiny 320x300 display, hence my leaning to a parallel display. If SPI can be used then that opens a lot of possible MCUs and I'd be happy.
Yes an ESP32 driving a ST7796S or SSD1963 would probably be best for me.
I still have the perhaps niggling question that an SPI interface would (perhaps) be slow, and that a Uno shield seems to be designed to be compatible with a Mega, with the bonus of lots of extra IO.
The 1963 was always a bad idea, I'm not paying that much money for an MCU display. (Some $80 where I live). An SPI ST7796S is on its way to me.
Bodmer's library looks really impressive. Thanks for the pointer to it.
