/HyperSPI

HyperHDR bridge using SPI bus. Connects Raspberry Pi with a generic Raspberry Pi Pico (rp2040)/ESP32/ESP8266 to control a LED strip. Fasted possible cable solution for external ESP LED driver. Data integration check included.

Primary LanguageC++MIT LicenseMIT

HyperSPI

SPI bridge for AWA protocol to control a LED strip from HyperHDR.
Diagnostic and performance data available at the serial port output read more.
Raspberry Pi acts as a master, ESP8266/ESP32/ESP32-S2/rp2040(Raspberry Pi Pico) is in slave mode.

LED strip / Device rp2040 / Pico ESP8266
(limited performance)		 ESP32 / ESP32-S2 mini
SK6812 cold white yes yes yes
SK6812 neutral white yes yes yes
WS281x yes yes yes

Why this project was created?

  • SPI is very faster. HyperSPI works best at speed over 20Mb
  • SPI doesn't have any data integration check. But AWA protocol does have one
  • you don't need to have 2Mb capable serial port on your ESP board
  • SPI transmission is much lighter than serial communication
  • There is a hardware limitation for the Rpi current design...even if you connect your grabber using USB2.0 mode, working serial port driver (used by Adalight) results in quite a large overall USB transfer. So we can replace Adalight with a pure SPI data transfer as an alternative
  • I needed it and I was able to implemented it 😉

Hardware connection

If you are using an ESP board compatible with the Wemos board (ESP8266 Wemos D1/pro, ESP32 MH-ET Live, ESP32-S2 lolin mini), the SPI connection uses the same pinout location on the ESP board! The pin positions of the LED output may vary. Cables (including ground) should not exceed 15-20cm or it may be necessary to lower the SPI speed.

The photos below use the same home-made adapter throughout, so you can see a repeating pattern and the cable colors should help you locate the correct pins. However, always consult the GPIO diagram for your boards to confirm that you have connected the cables correctly, because if you make a mistake and connect to the 5V GPIO line, it may damage both devices.

As you can also notice, the pinout of the SPI0 interface is identical for the entire Raspberry Pi SBC family: 3, 4, 5, Zero 2W, etc.

See how easy it is to connect Raspberry Pi Pico (rp2040) to Raspberry Pi 5 using SPI

or if you prefer ESP32/ESP32-S2/Esp8266

Example of supported boards

Esp8266 Wemos D1 mini (CH340) and Wemos D1 mini pro (CP2104)

ESP32 MH-ET Live and ESP32-S2 Lolin mini (CDC)

Default pinout (can be changed for esp32 and esp32-s2)

PINOUT ESP8266 ESP32 ESP32-S2 lolin mini Pico (rp2040)
Clock (SCK) GPIO 14 GPIO 18 GPIO 7 GPIO 2
Data (MOSI) GPIO 13 GPIO 23 GPIO 11 GPIO 4
SPI Chip Select(e.g. CE0) not used GPIO 5 GPIO 12 GPIO 5
GROUND mandatory mandatory mandatory mandatory
LED output GPIO 2 GPIO 2 GPIO 2 GPIO 14

Caution

The ground connection between both GPIOs is as important as the other SPI data connections. The ground cable should be of a similar length as them and run directly next to them.

Flashing the firmware

There are two versions of the firmware for ESP32 and ESP32-S2. The 'factory' (in the recovery_firmware.zip archive) and the 'base' one. Factory firmware should be flashed to offset 0x0, base firmware to offset 0x10000.

Flashing ESP32-S2 Lolin mini

Requires using esptool.py to flash the firmware e.g.

  • esptool.py write_flash 0x10000 hyperspi_esp32_s2_mini_SK6812_RGBW_COLD.bin or
  • esptool.py write_flash 0x0 hyperspi_esp32_s2_mini_SK6812_RGBW_COLD.factory.bin

Troubleshooting: ESP32-S2 Lolin mini recovery procedure if the board is not detected or is malfunctioning.

  1. Put the board into dfu mode using board buttons: press Rst + 0 buttons, then release Rst, next release 0
    Do not reset or disconnect the board until the end of the recovery procedure.
  2. Execute esptool.py erase_flash
  3. Flash 'factory' version of the firmware e.g.
    esptool.py write_flash 0x0 hyperspi_esp32_s2_mini_SK6812_RGBW_COLD.factory.bin
  4. esptool.py is not able to automatically reset esp32-s2 when in dfu mode. Reconnect or hard reset it manually. The board should be detected as a COM port in the system.

Flashing generic Esp8266/ESP32

Recommend to use esphome-flasher
Or use esptool.py e.g.

  • esptool.py write_flash 0x10000 hyperspi_esp32_SK6812_RGBW_COLD.bin or
  • esptool.py write_flash 0x0 hyperspi_esp32_SK6812_RGBW_COLD.factory.bin

For RGBW LED strip like RGBW SK6812 NEUTRAL white choose: hyperspi_..._SK6812_RGBW_NEUTRAL.bin
For RGBW LED strip like RGBW SK6812 COLD white choose: hyperspi_..._SK6812_RGBW_COLD.bin
For RGB LED strip like WS8212b or RGB SK6812 variant choose: hyperspi_..._WS281x_RGB.bin

Software configuration (HyperHDR v17 and above)

In HyperHDR Image Processing→Smoothing→Update frequency you should do not exceed the maximum capacity of the device. Read more here: testing performance

Select esp8266 protocol for ESP proprietary SPI protocol, esp32 for ESP32 boards or 'standard' for other devices.
Make sure you set "Refresh time" to zero, "Baudrate" should be set to high but realistic value like 25 000 000.
Enabling "White channel calibration" is optional, if you want to fine tune the white channel balance of your sk6812 RGBW LED strip.

Benchmark results

ESP32 & ESP32-S2 parallel multi-segment mode

LED strip / Device ESP32 MH-ET LIVE mini
HyperSPI v9		 ESP32-S2 Lolin mini
HyperSPI v9
300LEDs sk6812
Refresh rate/continues output=100Hz
SECOND_SEGMENT_START_INDEX=150		 100 100
600LEDs sk6812
Refresh rate/continues output=83Hz
SECOND_SEGMENT_START_INDEX=300		 83 83
900LEDs sk6812
Refresh rate/continues output=55Hz
SECOND_SEGMENT_START_INDEX=450		 54-55 55

ESP32

LED strip / Device ESP32 MH ET Live
HyperSPI v9		 ESP32-S2 Lolin mini
HyperSPI v9
300LEDs RGBW
Refresh rate/continues output=83Hz		 83 83
600LEDs RGBW
Refresh rate/continues output=43Hz		 42-43 42
900LEDs RGBW
Refresh rate/continues output=28Hz		 28 28

ESP8266

LED strip / Device ESP8266 Wemos D1 Pro
HyperSPI v9
300LEDs RGBW
Refresh rate/continues output=70Hz		 70
600LEDs RGBW
Refresh rate/continues output=33Hz		 33
900LEDs RGBW
Refresh rate/continues output=22Hz		 22

Compiling

Currently we use PlatformIO to compile the project. Install Visual Studio Code and add PlatformIO plugin. This environment will take care of everything and compile the firmware for you. Low-level LED strip support is provided by my highly optimizated (pre-fill I2S DMA modes, turbo I2S parallel mode for up to 2 segments etc) version of Neopixelbus library: link.

But there is also an alternative and an easier way. Just fork the project and enable its Github Action. Use the online editor to make changes to the platformio.ini file, for example change default pin-outs or enable multi-segments support, and save it. Github Action will compile new firmware automatically in the Artifacts archive. It has never been so easy! Just remember to follow the steps in the correct order otherwise the Github Action may not be triggered the first time after saving the changes.

Tutorial: https://github.com/awawa-dev/HyperSPI/wiki

Multi-Segment Wiring (ESP32 and ESP32-S2 only)

Using parallel multi-segment allows you to double your Neopixel (e.g. sk6812 RGBW) LED strip refresh rate by dividing it into two smaller equal parts. Both smaller segments are perfectly in sync so you don't need to worry about it. Proposed example of building a multisegment:

  • Divide a long or dense strip of LEDs into 2 smaller equal parts. So SECOND_SEGMENT_START_INDEX in the HyperSPI firmware is the total number of LEDs divided by 2.
  • Build your first segment traditional way e.g. clockwise, so it starts somewhere in middle of the bottom of frame/TV and ends in the middle of the top of frame/TV
  • Start the second segment in the opposite direction to the first one e.g. counterclockwise (SECOND_SEGMENT_REVERSED option in the HyperSPI firmware configuration must be enabled). So it starts somewhere in the middle of the bottom of the frame/TV and ends in the middle of the top of the TV/frame. Both segments could be connected if possible at the top but only 5v and ground ( NOT the data line).
  • The data line starts for both segments somewhere in the middle of the bottom of the TV/frame (where each of the LED strips starts)
  • Configuration in HyperHDR does not change! It's should be configured as one, single continues segment. All is done in HyperSPI firmware transparently and does not affect LED strip configuration in HyperHDR.

You also must configure data pin in the platformio.ini. Review the comments at the top of the file:

  • SECOND_SEGMENT_DATA_PIN - These is data pin for your second strip

You add these to your board's config. Be sure to put -D in front of each setting.

Examples of final build_flags for 288 LEDs divided into 2 equal segments in the platformio.ini:

[env:SK6812_RGBW_COLD]
build_flags = -DNEOPIXEL_RGBW -DCOLD_WHITE -DDATA_PIN=2 ${env.build_flags} -DSECOND_SEGMENT_START_INDEX=144 -DSECOND_SEGMENT_DATA_PIN=4 -DSECOND_SEGMENT_REVERSED
...
[env:WS281x_RGB]
build_flags = -DNEOPIXEL_RGB -DDATA_PIN=2 ${env.build_flags} -DSECOND_SEGMENT_START_INDEX=144 -DSECOND_SEGMENT_DATA_PIN=4 -DSECOND_SEGMENT_REVERSED
...

Implementation example:

  • The diagram of the board for WS2812b/SK6812 including ESP32 and the SN74AHCT125N 74AHCT125 level shifter.

HyperSPI

Performance/debug output

The output is only available when HyperHDR is not using the device at the moment, so it should be disabled in the app for a while. Stores the last result when HyperHDR was running in the current session. You can read it from the serial port at a speed of 115200.

On Linux you can screen command.
First install it: sudo apt install screen. Adjust USB port if necessary and connect to the serial port:
screen /dev/ttyACM0 115200
If you want to exit screen press Ctrl-a then k and confirm exit.

You can also use Putty on Windows obraz

For testing maximum performance in HyperHDR enable Image Processing→Smoothing→Continuous output, high Update frequency in the same tab and set any color in the Remote control tab as an active effect. After testing you need to disable Continuous outputand set Update frequency according to your results.