Triple Cortex-M33 low-power portable display

[Zengfh]

I need to design a wrist display and a bicycle display that runs the same UI program:
 1. The wrist display needs to display GPS maps and other information. I chose 2 2.16" 480x480 Amoled, which has the same extremely low power consumption as a smartwatch. Its overall resolution is 960x480.
 2. The bicycle display has a relatively large space. I chose a 6" 480x960 display, which needs to be rotated 90 degrees to display the 960x480 UI.
 3. I referred to many MCUs and finally found that BK7258 is a very suitable chip. At cpu0: 240MHz + cpu1: 480MHz + cpu2: stop, 480x960 LCD driver + hardware 90-degree rotation display, the BK7258 chip only consumes 9mA@5V, which is great!
4. BK7258 is an open chip. Its reference documents and SDK can be checked on the official website, but after understanding that its SDK is not very good, I also checked the porting of micropython, although I haven't tested it yet.
https://docs.bekencorp.com/arminodoc/bk_aidk/bk7258/en/v2.0.1
https://docs.bekencorp.com/arminodoc/bk_avdk/bk7258/en/v2.0.1
https://docs.bekencorp.com/arminodoc/bk_idk/bk7258/en/v2.0.1
 
Official website resource download (of course, it can also be downloaded on github):  https://dl.bekencorp.com/
It also has an official forum:  https://armino.bekencorp.com/

5. I designed 2 PCB boards with BK7258, one is dual QSPI x2 mode to drive 2x 2.16" 480x480 QSPI Amoled, and the other PCB integrates 2 universal RGB 40P sockets: 3W SPI+RGB 565+TP and 4.3" 5" 7" 40P RGB565 interface.

6. I shared this design on hackaday. ： https://hackaday.io/project/205474-bk7258-240mhz2x480mhz-low-power-iot-platform
7. The enhanced BK7259 will soon be open to ordinary users. It has better hardware performance, and I think I will use it if it is yet to have excellent low power consumption. Some parameters of BK7259 are shown in the following picture:

[Zengfh]

The driving ability of BK7258 is better than that of ESP32S3, and the frame rate of lvgl can reach 50fps when driving the 7" 1024x600 LCD screen.
The list of LCD screens that have been tested is as follows:
#define LCD_TYPE_TFT021_480x480                        0
#define LCD_TYPE_TFT0273_320X320                      0
#define LCD_TYPE_TFT0276_480X480                      0
#define LCD_TYPE_TFT0399_400X960                      0
#define LCD_TYPE_TFT040_480X480                        0
#define LCD_TYPE_TFT050_480X854_ST7701S         0
#define LCD_TYPE_TFT060_480X960_ST7701S         0
#define LCD_TYPE_TFT062_480X1280_ST7701S       1
#define LCD_TYPE_TFT070_800X480_MD0700R        0
#define LCD_TYPE_TFT070_1024X600_MD0700R      0

[Zengfh]

Of course, there are many 3W SPI+RGB666+TP type LCD screens with 40P FPC wiring. I have listed the common models on the back of the PCB.
The global version of the 4G module has been added to the PCB of the wrist display, while the GPS module in the L1+L5 band has been integrated in two PCBs. There are also 4 sensors: gravity/acceleration/magnetic field/barometer/thermometer/hygrometer.

[Zengfh]

Add 2.8" 480x480 and 2.1" 480x480 round LCD screen driver
These two round screens are only different in size, and their resolution is exactly the same.
Simulated aviation instruments and motorcycle instruments use such screens.

[Zengfh]

The cover and front shell designed for the 6" 480x960 display have been installed.

[coromonadalix]

nice projects 

[Zengfh]

Micropython starts to run on bk7258.

[Zengfh]

Add driver for Amoled 1.75" 466x466
We have found a large-sized round smartwatch display with a resolution of 1.75" 466x466 AMOLED. On its left side is a maximum square display with a resolution of 2.16" 480x480 AMOLED. It boasts excellent display quality and low operating current. The current consumption is 75mA@5V when GPS is enabled. When GPS is turned off, the current consumption drops to 40mA.  Therefore, the total current consumption is CPU + 2x AMOLED = 40mA@5V.

[Zengfh]

​Add three drivers for the transflective  LCD screen
We tested three types of transflective LCD screens to determine which one consumed less current. Their dimensions, resolutions, and zero-backlight current are as follows:
3.0" 240x400 RLCD   5mA
4.0" 272x480 RLCD   10mA
5.0" 800x480 RLCD   56mA

[Zengfh]

M.2 B-Key module of BK7258
The NGFF mod library has added a new member. The BK7258 NGFF module has been designed. We will design a compatible BK7259 next month, which will integrate 480MHz Cortex-M55+480MHz Cortex-M52 MIPI CSI/DSI functionality, as well as a new Cortex-M7 500MHz chip with jpeg/png decoder, arbitrary angle rotator, DMA2D, and built-in 16MBytes 250MHz 16 bit DTR PSRAM.
We will use it to complete other designs, such as a card style computer with 82Key+4.58 "320x960 LCD touch screen and a 7-inch terminal screen.
A card computer will have 80+2 buttons, with TCA8418 connecting 80 QWERTY buttons and the other 2 serving as power on/off buttons connected to the MCU. Will use WS2812B LED on the side of the button.

[Zengfh]

The shell effect of the first version is shown in the following figure:
The buttons will be printed with soft silicone buttons for the best feel, but the printing cost is high.

[Zengfh]

A new CCM4211 500MHz Cortex-M7 NGFF compatible module is in the PCB production process. The most interesting news is that it can be connected to both QSPI Flash and QSPI Nand Flash externally. BootLoader will directly copy the code from QSPI Nand Flash to PSRAM to run, which means that the MCU's external Flash can start from 128M bytes to 1G bytes.

[Zengfh]

After printing the casing, we assembled the LCD and PCB board. The program starts running, and the low-power characteristics continue to be maintained. The current is 11mA@5V When the LCD is removed, the current is 78mA@5V When the screen is running at 50% brightness.

[Zengfh]

We upgraded the PCB of the 4.58 "320x960 card computer, using a 4.35V 6000mAh battery, and paired it with an axp2585 PMU chip for maximum 3A fast charging and coulombic meter power measurement. Four sensor chips were placed: six axis/magnetometer/barometer/hygrometer. Silicone buttons are currently in production, using a high-precision process called replication molding. We will try using UV stickers for the characters on the buttons, and it will come back soon.
There are two B-Key M.2 sockets on the motherboard, one of which is BK7258. Of course, CCM4211 can also be installed and debugged on it now. The other one is a 4G+GPS module.

[unikeyname]

Impressive, but is your purpose putting dev log in this forum?

I just feel it is a bit spam-my for me, you can condense development log in somewhere else.

EDIT: no offense intended, I am just here for interesting work you introduce. Sadly I and some other dont understand an awful lot on this project so it mostly looks like you are monologuing here.

[unikeyname]

The driving ability of BK7258 is better than that of ESP32S3

in serious work, if anyone had leaned too hard into espressif ecosystem they should choose a P4 either way no?
and how does that compare to 7259? I also have lots of interest in BK chip but the SDK is dulled and not much content can be found online.

[unikeyname]

Add driver for Amoled 1.75" 466x466
We have found a large-sized round smartwatch display with a resolution of 1.75" 466x466 AMOLED. On its left side is a maximum square display with a resolution of 2.16" 480x480 AMOLED. It boasts excellent display quality and low operating current. The current consumption is 75mA@5V when GPS is enabled. When GPS is turned off, the current consumption drops to 40mA.  Therefore, the total current consumption is CPU + 2x AMOLED = 40mA@5V.

I saw an awful lot of antenna here. Seems like it's really worth it choosing CA antenna instead of drawing PCB Antenna no? Love to know the reason for the need of that many of them.

[unikeyname]

why do you guy with keypad and not a minimal set of hard button and utilizing touch input instead?

[Zengfh]

Yes, the project is in progress, so I have recorded the details of any improvements. Many details may not be remembered if the project has already been completed,.

[Zengfh]

The driving ability of BK7258 is better than that of ESP32S3

in serious work, if anyone had leaned too hard into espressif ecosystem they should choose a P4 either way no?
and how does that compare to 7259? I also have lots of interest in BK chip but the SDK is dulled and not much content can be found online.

I use it because of its ultra-low power consumption. The BK7258's CPU0 240MHz+CPU1 480MHz+8M Flash+16M PSRAM+LCD 320x960 driver+90 degree hardware rotation current is 9mA @ 5V or 14mA @ 3.3V, so I designed this prototype now. It can run micropython, which is suitable for my children to practice programming.

BK7259 is still in the engineering sample stage. I will go to BK to discuss a project next week and start its development.

BK7259 is Cortex-M52 480MHz + Cortex M58 480MHz，SIP 16M~32M Flash + SIP 32M PSRAM ,MIPI-CSI, MIPI-DSI， More specific parameters will only be available after next week's interview.
I use CA's antenna because they have a professional environment to test and advise on RF, and it is smaller in size.

The integration of touch and keyboard is for programming beginners, and the introduction of TTL serial port is for situations where only serial port debugging is required, such as production debugging of some Linux boards where only the serial port needs to be turned on on the computer. 

[unikeyname]

The integration of touch and keyboard is for programming beginners, and the introduction of TTL serial port is for situations where only serial port debugging is required, such as production debugging of some Linux boards where only the serial port needs to be turned on on the computer.

thanks for your clarification, it makes the perfect sense.

[Zengfh]

The integration of touch and keyboard is for programming beginners, and the introduction of TTL serial port is for situations where only serial port debugging is required, such as production debugging of some Linux boards where only the serial port needs to be turned on on the computer.

thanks for your clarification, it makes the perfect sense.

Additionally, GPS uses two antennas in the L1+L5 frequency band, WIFI/BT uses one antenna, and 4G module uses one antenna, so patch antennas should be a good choice.

[unikeyname]

Additionally, GPS uses two antennas in the L1+L5 frequency band, WIFI/BT uses one antenna, and 4G module uses one antenna, so patch antennas should be a good choice.

That's great. I have been advised against doing SMD antenna from CrossAir many times since the changes are significant comparing to just do PCB Antenna... So it's great looking at the design use it extensively, and I will incorporate those into new design instead.

[Zengfh]

Additionally, GPS uses two antennas in the L1+L5 frequency band, WIFI/BT uses one antenna, and 4G module uses one antenna, so patch antennas should be a good choice.

That's great. I have been advised against doing SMD antenna from CrossAir many times since the changes are significant comparing to just do PCB Antenna... So it's great looking at the design use it extensively, and I will incorporate those into new design instead.

Y, it can save PCB area and is very easy to match. In addition, CrossAir welcomes customers to test and adjust their PCBs with them, and their environment is very professional.

[unikeyname]

Y, it can save PCB area and is very easy to match. In addition, CrossAir welcomes customers to test and adjust their PCBs with them, and their environment is very professional.

how can I get contact with their FAE? I can add their V.

EDIT: or adding yours