Malaysia-based Cytron has a history of creating fun Maker boards.from maker hat, Maker Pipikoand focused on robotics Manufacturer Pi RP2040 It’s clear that Cytron caters to the manufacturer market. For the latest board, his $56 CM4 Maker Board, we see a shift in focus from the mainstream. Raspberry PMe and raspberry pi pico,fart raspberry pi compute module 4.
The CM4 Maker Board is a Swiss Army knife. It provides all the connections you need to connect HATs, sensors, and high-speed NVMe SSDs in a 110 x 110 mm package. But does this versatility detract from its functionality? To understand this and learn more about the board, I put it on a new test bench and started testing.
CM4 Maker Board Specifications
| socket | Compute module 4 |
| GPIOs | Full 40-pin Raspberry Pi compatible GPIO |
| 5 x Maker Ports (Grove Connectors) | |
| 1 x Stemma QT (Qwiic / QW/ST compatible) | |
| 10x GPIO LEDs | |
| 3 x pushbutton inputs | |
| Piezo Buzzer (GPIO 19) | |
| Headphone audio output (GPIO18 and 19) | |
| real time clock | |
| port | USB2×4 |
| gigabit ethernet | |
| HDMI (4K60) | |
| USB C (Power and OS to flash eMMC) | |
| 1 x camera (CSI) connector | |
| 1 x Display (DSI) connector | |
| depository | Micro SD slot for CM4 Lite |
| M.2 NVMe for 2230 and 2242 drives | |
| Power | 5V over USB-C |
| 7-18V via DC Jack | |
| Onboard power switch and breakout for external power button | |
| size | 110×110×17.3mm |
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Similar to the Cytron board, it is greeted with a distinctive purple PCB. The silkscreen is easy to read and makes it easy to see which GPIO pins many of the ports and LEDs are connected to. Be careful not to use SATA drives, even M.2 sockets. The layout of the CM4 Maker board resembles a typical PC motherboard rather than a single board computer.
All major ports (USB, Ethernet, power, etc.) are on one side of the board. Having four USB 2 ports would be nice, but it would have been nice to have had USB 3 ports as the only way to get fast storage is with an M.2 NVMe connection. On the other side are the Maker Ports, Cytron’s Grove name, and the Stemma QT connector.
There were no wires in the box, but luckily we have a good selection of both Grove and Stemma QT components. Compute Module 4 is centered on the board with a silkscreen showing its orientation. Like many other CM4 carrier boards, it can be inserted upside down. Make sure the holes line up before pushing down.
An NVMe 2230 or 2242 SSD can be installed just below the CM4 socket, to the right of the CR2032 battery holder for the real-time clock. I installed a 128GB Cytron Makerdisk and then installed the Raspberry Pi OS on the eMMC of the Compute Module 4 test unit. I then used the Raspberry Pi OS’s SD Card Copier to copy the installation to the NVMe drive.
Oddly, booting from NVMe is not as fast as eMMC. About 6 seconds slower than eMMC, NVMe really shines when used for general computing tasks. The sequential write speed of 367 MBps is much faster compared to eMMC’s 70MB/s. Finally, we tested a 64GB Class 10 A1 SDXC card, which showed the slowest sequential write speed of 29.5 MB in this test.
| Header Cell – Column 0 | Boot time (seconds) | Sequential write speed |
|---|---|---|
| NVMe | 30.63 | 376643KB/s |
| eMMC | 24.25 | 72575KB/s |
| Micro SD | 26.85 | 30214KB/s |
Using the Cytron CM4 Maker Board
Once the OS was installed on the NVMe drive, I started the GPIO testing process. First, I wanted to control an LED connected to a specific her GPIO pin. They are a convenient way to check the state of GPIO pins and can be used to test that the GPIO library for a particular programming language is working correctly without having to wire anything up.
After playing with LEDs, I used GPIO zero to test three buttons connected to GPIO17, 22 and 27. Next, I decided to test my musical prowess with the onboard piezo buzzer. I was able to hook up to GPIO19 and “compose” a short song that would never get picked up by any publisher.
There are two more buttons near the USB-C port. These buttons are for safely powering off the board. Using Cytron’s install script, I was able to configure the board to react when both buttons are pressed. This will trigger a graceful shutdown of Compute Module 4. Just above are two pins that duplicate the functionality of the button. These pins can be connected to buttons on the outside of the case. So if you want to embed your Pi into an old PC case, it will come in handy.
With the board powered off, I plugged in a HAT, specifically Pimoroni’s Explorer HAT Pro. This HAT is the HAT on the Best Raspberry Pi HAT list and is also the board I used to teach programming. After running some tests with I2C enabled, I can say that the GPIO is fine. I just wish there were some M2.5 spacers in the box, and when I pressed the Explorer HAT Pro’s button it remained dangerously close to the CM4’s SoC.
Of interest are the Maker ports along one edge of the board.you can connect here Grove compatible components to digital GPIO pins, PWM, UART, and I2C. To easily test the Maker port, I turned to Adafruit’s CircuitPython library. Because you can easily connect sensors and components.
The first component to test was a 128×64 OLED display using the I2C protocol. Once I found the library and created a test script, the randomized starfields were dancing across the screen in no time. next, Stema QTIn fact, this port is so small and hidden that I missed it at first. I hooked up the Adafruit MPU 6050 6 DOF accelerometer and gyro sensor, installed the libraries, and wrote a few lines of code to stream the data to the Python REPL.
A quick camera test is where I ran into the first “gotcha”.i really should have read the manualCompute Module 4 must be configured to use the camera. After running the necessary scripts, I tried again and captured a beautifully sharp shot of myself testing the camera. I used the latest wide angle camera module 3 with autofocus and everything worked fine after that. I haven’t had a chance to test DisplayPort since I moved office spaces and couldn’t find an official display.
What kind of projects is Cytron’s CM4 Maker board suitable for?
The Cytron CM4 Maker Board is suitable for all projects, especially those that may work on the Raspberry Pi Model B. Unfortunately, the Raspberry Pi Compute Module 4 is often the hardest board to find in stock. There are specific reasons for that.
Cytron’s CM4 Maker Board is more of a Swiss Army knife than a scalpel. It does not have one great feature, but many. Having a GPIO port and a Maker port would be nice, but the same functionality is available in the HAT on the Raspberry Pi. His NVMe slot onboard is welcome and provides significant speed to the Raspberry Pi OS.
The original idea for the CM4 Maker Board was to use it as a base for arcade cabinet builds. Aligned ports act like the motherboard in your PC case, providing access to ports while keeping everything tidy. NVMe drives provide fast access to emulators and ROMs, and compatibility with HATs allows the use of Pimoroni’s easy-to-wire Picade HATs. Another project could be a sensor station that collects data from sensors connected to Maker ports and GPIOs.
Conclusion
I loved my time on this board. Camera issues aside, I had to read the manual, but this board worked great and did a great job.When using a HAT with a Compute Module 4, booting from NVMe, or Stemma QT/Grove If you use components, this board is perfect for you. Its adaptable nature makes it useful for many projects. Make sure you have a project in mind before purchasing.
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