The ClockworkPi V5 compared to the V4, corrected the power management power consumption issue

I have these two devices, and I also have the core board A06 R01 CM3 and the CM4 adapter board. I have done detailed evaluations and comparisons. The two mainboards are different, namely V4 and V5.

Their battery modules are exactly the same and can be used interchangeably. Their boards can be used interchangeably. I replaced the v4 motherboard in uconsole and installed a 4g expansion card, and everything is running well.

The main changes can be found in the power supply part. I compared the differences between the motherboards in this video uConsole 使用感受 上网游戏以及配件互换_哔哩哔哩_bilibili

The power problem of devterm has been raised by many people, and the main problems are as follows:

1 After being placed for a period of time, pressing the power button cannot turn on the machine.
After plugging in the USB power supply, it can be turned on normally, but when entering the system, there is enough battery power.
2 In my CM3 devterm, it basically drains the battery after 5 days, which is very unfriendly to batteries without protection. A qualified circuit should not lose power so quickly after turning off the power.
3 The A06 core cannot wake up after sleep, showing that the screen is bright but black, and only a hard shutdown is possible.
4 After my devterm is turned off, USB still has power supply, and the red light of the photoelectric mouse will always be on until the battery is exhausted.

The above problems have been raised in the community, and some have been resolved, but there is no official explanation of the reasons and correction plans.

In order to prove my point of view, I tested them by exchanging them. I plugged in a mouse and checked the power supply status of the USB through the red light.

Test without inserting a system TF card, So it has nothing to do with your system image. Press the power button to turn on, long press until the power light goes out to indicate shutdown.

The v4 motherboard configured by devterm, installing the CM3 core, turn on the power, USB red light is on, long press to turn off the power, red light still does not go out. This means that devices including USB and keyboard are always working. The only way is to remove the battery.

V4 motherboard, equipped with A06 R01 CM4 cores such as these cores, turn on the power, USB red light is on, long press to turn off the power, red light goes out. It means that hardware shutdown can control cutting off USB power supply.

And uconsole’s V5 motherboard, after installing CM3 core, turn on the power supply, USB red light does not light up, indicating that it does not wake up USB power supply before entering the system.

In summary: The v5 motherboard has corrected the wake-up and disconnection of power. While at least when paired with CM3 on v4 motherboard, there are serious problems. Neither soft nor hard shutdown will cut off your USB power supply until your battery runs out. CM3 should be the most suitable standard for official motherboards. It is a pity that there are such problems when paired with v4. If anyone knows how to modify it, please tell me that I am looking forward to using CM3 on devterm.


I have experienced the same power issue with my DevTerm, if I use the device and then power it off, several days later the batteries will be dead. Removing the batteries to store it is annoying and I don’t use it very often because of this. Sad :frowning:

I purchased protected cells just a few days after i ordered the uConsole after seeing that it shared so many components with the DevTerm. That was well before it was revealed that the uConsole was using a revised motherboard. The protected cells i have are a lot more snug, but fit without issues and without modifying the battery holder like i was originally thinking i would need to. According to the uConsole store page the uConsole’s battery holder is a bit larger allowing for a wider range of compatible cells.

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Protected cells only prevent over-discharging, overcharging, and some thermal issues, they don’t prevent parasitic drain on their own. Point being, there are earlier board revisions that do have a drain issue no matter what cells are used. As @chnjyxz pointed out, this is more concerning the v4 board, I would like to see a solution as well.

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If I recall correctly, I believe the problem was from the CM3 leaking 3v3 back onto the base board and keeping the 5v switching circuit on. It was mentioned on the discord (probably by me ¯\_(ツ)_/¯). I think someone (@markatlnk?) added a pull-down resistor to fix the problem.

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I remember that… I just changed the value of one resistor so it would shut down properly. Posted about that fix long ago.

I would still love to see an image to run the CM3 module in the uConsole.

The DevTerm with the CM3 (after the resistor mod) shuts down properly. Just powered my DevTerm up, it has been sitting for a week or so and nearly has a full battery. Just search for my name, it should pop up.

search not found :neutral_face:

@chnjyxz Discord

@markatlnk I heard you added resistors to your uconsole too :laughing:

I did, it shuts down just fine. Let me dig up my notes.

I actually meant Improving action on the keyboard :crazy_face:

I did… Those dome switches when you press nicely in the center with a smooth somewhat soft button, it takes the most force. By taping small hard items to the top of each switch, it collapses easier and results in a lighter touch. The original pressure was quite a bit more than I liked. Any small hard item will do and SMT resistors are really hard and I have a bunch of them. Nothing special about resistors, just something hard and small.

@pkr @markatlnk @yatli Thank you, I have found a way to modify the R108.

Another question, about the discussion in a06, connecting the R124 resistor and adding a 10K resistor between R116 and R508, can this also reduce the loss after the battery is shut down? Do I need to mod it together?

Guessing not, for you to wake it back up the keyboard or mouse need to work. For those to work you need the USB powered up.

@chnjyxz that A06 mod is only for suspend power savings. As far as I know, RPi devices do not support suspend at all.

@markatlnk actually, the only way to power back up after suspend (at least with A06) is via power button or usb-c power input, so in that case keeping the USB/keyboard powered was a waste of precious energy.

I don’t know much about technology, but I think a06 suspension may be very slow because so much memory is a burden on the SD card, and a lot of reading and writing will also reduce its lifespan.

Ah, it is suspend-to-ram, not suspend to disk. Very very fast.

With the USB power mod it takes an additional 2-3 seconds for the keyboard to reconnect though.

suspend-to-ram should be instant, but I waste over a second to make sure audio pipe is empty first…

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if a06 suspend-to-ram need R124 and 10k resistor?
I don’t know if they have fixed this issue in the v5 motherboard

The mod will turn off the base board USB power (but not on the expansion card) during suspend-to-ram. To test, just plug in something (optical mouse?) to the base board USB port and try to suspend, checking if your USB device turns off. Obviously you’ll need to have suspend working properly first…

I have a v5 motherboard with a06 installed, and the test can be suspended, press the power button to restore, but the USB is always powered.