Design hardware based on CM4 for pikvm:https://github.com/pikvm/pikvm.
This device helps to manage servers or workstations remotely, regardless of the health of the operating system or whether one is installed.
BLIKVM is a CM4 application board for PiKVM. This product’s key features include video capture, ATX adapter, USB 3.0, OTG, Gigabit Ethernet, OLED and RTC. The product has a customized metal shell to dissipate heat and provide protection for the circuit board. This is a feature demonstration video.The product is currently perfectly compatible with v3-hdmi-rpi4-latest.img.
The product integrates video capture function, and the bridge chip is TC358743. The product supports HDMI video and audio capture. Currently, PiKVM software only supports video capture, not audio capture. For the audio coding method, please refer to the documentation of C780.
The user can use the ATX cable provided with the product to connect the product and the motherboard ATX switch of the controlled computer. The length of the ATX cable is 60CM, you can also use the double female Dupont cables.
The USB3.0 interface is provided by a USB 3 host controller (using the Via Labs VLI805), which is connected to the internal PCIe 2.0 x1 host controller of CM4.
This port is doing the emulation of a USB keyboard, mouse, Virtual CD-ROM or USB Flash Drive, USB-Ethernet, USB-Serial port and a lot of other Linux-supported features. This interface cannot provide external power.
The RTC clock chip is DS1307. The chip is connected to the I^2^C interface of CM4, and the wiring definition is shown in the following table. Users need to buy 1220 button batteries locally.
| DS1307 | CM4 |
|---|---|
| SCL | GPIO3(SCL1,I^2^C) |
| SDA | GPIO2(SDA1,I^2^C) |
Follow the method below to enable RTC(Use the latest v3-hdmi-rpi4-latest.img,IIC is enabled by default).
- Open the startup configuration file of the Raspberry Pi
# sudo nano /boot/config.txt //Raspberry Pi's startup configuration file
- Find the corresponding code, modify it as follows, and configure it as DS1307 chip
dtoverlay=i2c-rtc,ds1307
- Reboot the system
# sudo reboot
- Synchronize time from Raspberry Pi to DS1307
# date //Display the current time of the Raspberry Pi
# sudo hwclock -w //Write the time of Raspberry Pi to DS1307
# sudo hwclock -r //Read the time of DS1307
A standard 1:1 RJ45 MagJack with added ESD protection.
This LED duplicates the function of the GREEN LED on the Raspberry Pi 4, Model B. Under Linux this LED will flash to signify eMMC access, while if there is an error during booting this LED will flash error patterns which can be decoded using the look up table on the Raspberry Pi website.
The micro SD Card socket is a PUSH-PUSH socket. To release the micro SD Card a gentle push on the micro SD Card will enable it to be removed.
This LED duplicates the function of the RED LED on the Raspberry Pi 4, Model B.
The product comes standard with a monochrome OLED display with a resolution of 128x64, and the chip is SSD1306. The user connects the display to the product with the wiring of the display.
The module is connected to CM4 through the I^2^C interface. The wiring definition is shown in the following table. This is a library for the monochrome OLEDs based on SSD1306 drivers.
| Display(SSD1306) | CM4 |
|---|---|
| GND | GND |
| VCC | 3.3V |
| SCL | GPIO3(SCL1,I^2^C) |
| SDA | GPIO2(SDA1,I^2^C) |
Follow the method below to enable RTC(Use the latest v3-hdmi-rpi4-latest.img,IIC is enabled by default).
Log in to PiKVM and run these commands:
# rw
# systemctl enable --now kvmd-oled //Enable OLED
# ro
- G: GND
- BOOT: nRPI_BOOT
During boot if the nRPI_BOOT pin is low booting from eMMC will be stopped and booting will be transferred to rpi boot which is via USB.
The CM4 requires a good quality USB-C power supply capable of delivering 5V at 3A. If attached downstream USB devices consume less than 500mA, a 5V, 2.5A supply may be used.
It is recommended to use 5V 0.15A 3010 DC brushless fan.
Newer keeps the factory state, ignore this switch. Only flip the switch when the device is powered off, otherwise it may cause permanent damage! The four small switches should be up or down at the same time.
The video encoding function of the Raspberry Pi is implemented by the HDMI-to-CSI bridge chip Toshiba TC358743, which supports up to 4 CSI-2 date lanes. The camera interface of Raspberry Pi 4B only supports 2 CSI-2 date lanes(up to 1080p50fps), Raspberry Pi CM4 can support 4 CSI-2 date lanes(up to 1080p60fps). Currently, PiKVM only uses two CSI-2 channels.
Used to install CM4
The metal shell provides protection for the circuit board, and the equipped 5V DC brushless fan can enhance heat dissipation. SMA antenna hole is reserved on the shell, CM4 can use an external antenna.
In this path: video/, there are some 3D models of videos.
If you are interested in this hardware, please email me anytime.
email address:linshuzi123@gmail.com
skype group: https://join.skype.com/3ORIRT2OIZ0S
https://www.youtube.com/watch?v=aehOawHklGE https://www.youtube.com/watch?v=d7I9l5yG5M8
Purchase：BLIKVM