Qualia ESP32-S3 for TTL RGB-666 Displays

by Adafruit

Image of Board

There’s a few things everyone loves: ice cream, kittens, and honkin’ large TFT screens. We’re no strangers to small TFT’s - from our itsy 1.14” color display that graces many-a-TFT-Feather to our fancy 3.5” 320x480 breakout screen. But most people who dabble or engineer with microcontrollers know that you sort of ‘top out’ at 320x480 - that’s the largest resolution you can use with every day SPI or 8-bit 8080 interfaces. After that, you’re in TTL-interface TFT land, where displays no longer have an internal memory buffer and instead the controller has to continuously write scanline data over a 16 or 18 or 24 pin interface.

RGB TTL interface TFT displays can get big: they start out at around 4.3” diagonal 480x272, and can get to 800x480, 800x600 or even 720x720. For displays that big, you need a lot of video RAM (800x480 at 24 bit color is just over 1MB), plenty of spare GPIO to dedicate, and a peripheral that will DMA the video RAM out to the display continuously. This is a setup familiar to people working with hefty microcontrollers or microcomputers, the sort of device that run cell phones, or your car’s GPS navigation screen. But until now, nearly impossible to use on low cost microcontrollers.

The ESP32-S3 is the first low-cost microcontroller that has a built in peripheral that can drive TTL displays, and can come with enough PSRAM to buffer those large images. For example, on the Adafruit Qualia ESP32-S3 for TTL RGB-666 Displays, we use a S3 module with 16 MB of Flash and 8 MB of octal PSRAM. Using the built in RGB display peripheral you can display graphics, images, animations or even video (cinepak, natch!) with near-instantaneous updates since the whole screen gets updated every ~30FPS.

This dev board is designed to make it easy for you to explore displays that use the “secondary standard’ 40-pin RGB-666 connector. This pin order is most commonly seen on square, round and bar displays. You’ll want to compare the display you’re using to this datasheet, if it matches you’ll probably be good! One nice thing about this connector ordering is that it also includes pins for capacitive touch overlay, and we wire those up to the ESP32-S3’s I2C port so you can also have touch control with your display.

Don’t forget! This is just the development board, a display is not included. Use any RGB-666 pinout display with or without a touch overlay. Note that you will need to program in the driver initialization code, dimensions, and pulse widths in your programming language. Here are some known-working displays that you can use in Arduino or CircuitPython:

On the Qualia board we have the S3 modules, with 16 pins connected to the TFT for 5-6-5 RGB color, plus HSync, VSync, Data Enable and Pixel Clock. There’s a constant current backlight control circuit using the TPS61169 which can get up to 30V forward voltage and can be configured for 25mA-200mA in 25mA increments (default is 25mA). Power and programming is provided over a USB C connector, wired to the S3’s native USB port. For debugging, the hardware UART TX pin is available as well.

Since almost every GPIO is used, and almost all RGB-666 displays need to be initialized over SPI, we put a PCA9554 I/O expander on the shared I2C bus. Arduino or CircuitPython can be instructed on how to use the expander to reset and init the display you have if necessary. The remaining expander pins are connected to two right-angle buttons, and the display backlight.

The expander is what lets us have a full 4-pin SPI port and two more analog GPIO pins - enough to wire up an MMC in 1-wire SDIO mode along with an I2S amplifier to make an A/V playback demo. Maybe we can even eat ice cream while watching kitten vids! There is also the shared I2C port, we provide a Stemma QT / Qwiic port for easy addition of any sensor or device you like.



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CircuitPython 9.0.0-alpha.5

This is the latest development release of CircuitPython that will work with the Qualia ESP32-S3 for TTL RGB-666 Displays.

Alpha development releases are early releases. They are unfinished, are likely to have bugs, and the features they provide may change. Beta releases may have some bugs and unfinished features, but should be suitable for many uses. A Release Candidate (rc) release is considered done and will become the next stable release, assuming no further issues are found.

Please try alpha, beta, and rc releases if you are able. Your testing is invaluable: it helps us uncover and find issues quickly.

Release Notes for 9.0.0-alpha.5

Built-in modules available: _asyncio, _bleio, _pixelmap, adafruit_bus_device, adafruit_pixelbuf, aesio, alarm, analogbufio, analogio, array, atexit, audiobusio, audiocore, audiomixer, binascii, bitbangio, bitmaptools, board, builtins, builtins.pow3, busdisplay, busio, busio.SPI, busio.UART, canio, collections, countio, digitalio, displayio, dotclockframebuffer, dualbank, epaperdisplay, errno, espcamera, espidf, espnow, espulp, fontio, fourwire, framebufferio, frequencyio, getpass, gifio, hashlib, i2cdisplaybus, i2ctarget, io, ipaddress, json, keypad, keypad.KeyMatrix, keypad.Keys, keypad.ShiftRegisterKeys, locale, math, mdns, memorymap, microcontroller, msgpack, neopixel_write, nvm, onewireio, os, os.getenv, ps2io, pulseio, pwmio, qrio, rainbowio, random, re, rgbmatrix, rotaryio, rtc, sdcardio, select, sharpdisplay, socketpool, ssl, storage, struct, supervisor, synthio, sys, terminalio, time, touchio, traceback, ulab, usb_cdc, usb_hid, usb_midi, vectorio, warnings, watchdog, wifi, zlib

Absolute Newest

Every time we commit new code to CircuitPython we automatically build binaries for each board and language. The binaries are stored on Amazon S3, organized by board, and then by language. These releases are even newer than the development release listed above. Try them if you want the absolute latest and are feeling daring or want to see if a problem has been fixed.

Previous Versions of CircuitPython

All previous releases of CircuitPython are available for download from Amazon S3 through the button below. For very old releases, look in the OLD/ folder for each board. Release notes for each release are available at GitHub button below.

Older releases are useful for testing if you something appears to be broken in a newer release but used to work, or if you have older code that depends on features only available in an older release. Otherwise we recommend using the latest stable release.

Install, Repair, or Update UF2 Bootloader

Latest version: 0.18.1

The UF2 bootloader allows you to load CircuitPython, MakeCode, and Arduino programs. The bootloader is not CircuitPython. If a UF2 bootloader is installed, you can check its version by looking in the INFO_UF2.TXT file when the BOOT drive is visible (FTHRS2BOOT, MAGTAGBOOT, HOUSEBOOT, etc.)

It is not necessary to reinstall a UF2 bootloader you unless a BOOT drive is not visible when in UF2 bootloader mode, or you know of a problem with your current UF2 bootloader.

If a UF2 bootloader has never been installed on the board, or the UF2 bootloader was removed by erasing or overwriting the flash, the UF2 bootloader must be installed in order to flash .uf2 files onto the board. .bin files can be uploaded without a UF2 bootloader, using the ESP Web Flasher or esptool.py.

Note: update.uf2 files are not currently working on ESP32-S2 or ESP32-S3 boards.

Important: this will erase previously flashed firmware and sketches from the board, but needs to be perfomed only once.

The instructions here are general. We recommend you consult the manufacturer's board documentation for detailed instructions, which may be different.

  • Unzip to find the file combined.bin.
  • Place board in bootloader mode:
    • Plug board into a USB port on your computer using a data/sync cable. Make sure it is the only board plugged in, and that a charge-only cable is not being used.
    • Press and hold down the BOOT or 0 button.
    • Press and release the RESET or RST button.
    • Release the BOOT button.
  • Upload combined.bin (Google Chrome 89 or newer):
    • Open ESP Web Flasher in a new window/tab.
    • Select 460800 Baud from the pull-down menu (top-right).
    • Click Connect (top-right).
    • Select the COM or Serial port from the pop-up window.
    • After successful connection, click Erase.
    • After successful erase, click any Choose a file..., then locate and select the combined.bin file unzipped earlier.
    • After successfully choosing combined.bin, click Program.
    • After the TinyUF2 firmware update is complete, press the RESET button on the board. A new drive BOOT should be visible in your file browser.

After installing the UF2 bootloader, enter the bootloader by double-clicking the reset button. On boards with an RGB status LED, tap reset once, wait for the LED to turn purple, and tap again before the purple goes away. On other boards, consult the board documentation.

After you update, check INFO_UF2.TXT to verify that the bootloader version has been updated. Then you will need to load or reload CircuitPython using the .uf2 file.