Hi there! I was wondering if you would be able to answer a few questions I have about the CM3. From what I’ve seen, I think it’s a brilliant device in general, and I’m considering getting one to develop with.
For some time now, I’ve been working on building a Debian-based desktop and mobile operating system/platform called LiveG OS, which is currently designed to run on the PINE64 PinePhone, as well as desktop/laptop computers with the AMD64 architecture. It’s very basic in terms of functionality at the moment, but we’re looking to grow the platform.
One project that I’ve had in mind is to build a complete, open smartphone that runs on this OS and that is easy to build and repair (see our current prototype, based on the PinePhone). The CM3 looks like an ideal compute module to integrate into this (as-yet-nonexistent) project, but I was just wondering about some of the specific details about the specs:
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How much power does the CM3 roughly consume?
It’s great that it appears that the CM3 can enter a sleep mode to conserve power (you might have to confirm/correct me on this), which the Raspberry Pi CM4 can’t do; so the CM3 would be a good device for a portable solution. It’d just be nice to know how much power the CM3 needs to run so that I can get an estimate for how long the device would be able to run for on a battery. -
Is there any more information about connecting a battery to the CM3?
From what I’ve seen on the CM3 pinout page on the Radxa site, pins 78-88 (even-numbered pins only) appear to allow for a battery to be connected. Can the CM3 charge up a regular mobile 3.7V LiPo/LiIon battery and run off of it like a conventional smartphone can? Is there a way to monitor battery consumption and state (such as charging/discharging as well as remaining capacity) through software? That would make life much easier compared to using the RPi CM4. -
Is USB-C supported?
I believe that the carrier board uses a 12V DC barrel jack, but would the CM3 also support a USB-C interface? It would be nice to use USB-C for both supplying power to the device and battery, as well as being able to connect other USB devices through the same port (maybe even also DisplayPort for convergence!). The specs for the CM3 say that a single 5V PSU input can be used, so I imagine that it’s not too hard to implement USB-C. -
What sort of screens can connect to the CM3’s MIPI DSI pins? Has there been much success in driving a variety of displays?
I’m thinking about connecting the LPM060A549A display to the CM3 (it’s listed on Panelook), which is a display used for the Xiaomi Mi 6X A2 phone, and is a touchscreen display. It uses a 4-lane MIPI connection for the LCD and an I2C interface for the touch I believe (I can provide a datasheet if needed). How hard do you think it would be to connect this up, roughly? -
What sort of cameras are compatible with the CM3?
I understand that there are many cameras that can connect over MIPI CSI. What cameras are known to work with the CM3? (Preferably cameras that do not have a carrier PCB and only just a ribbon/flex cable — it’d be nice to have something compact!) I think that it’s great that having two connected cameras is supported, since one can be used for the front (selfie) camera, and the other for the back camera. I know the PinePhone Pro uses the OV8858 and Sony IMX258 cameras, which I believe both use MIPI CSI.
I’m also planning to use a Quectel EG25-G module, which I believe has been known to work with the RPi CM4, and I expect it to therefore work with the CM3 too. That’ll be something I’ll need to think about connecting up later, but with mPCIe support on the CM3, it should hopefully be relatively straightforward I think.
Sorry for the barrage of questions — I know there’s quite a lot, but it’d be really helpful for me to get more info about this awesome SoM! No worries if you aren’t able to ask them all; there might be more questions later on as I delve more into learning about the CM3. I really appreciate any answers/info about others’ experiences with the device.
Many thanks,
-James.
If you would like this information to be made available in another language for clarity, please let us know. Please note that LiveG Technologies is not a commercial organisation, and is at this stage only a community project run by volunteers.
如果您需要此信息的其他语言版本（为清楚起见），请告知我们。请注意，LiveG Technologies（力格）不是商业组织，现阶段只是一个由志愿者运营的社区项目。