Units

Adding a switch to the DinMeter

cdnstig — Fri, 10 Apr 2026 13:02:13 GMT

In case anyone else comes across this post, it appears that the wires coming out of the DinMeter PortB are reversed to the label, at least on my unit. G1 is the yellow wire, and G2 is the white one. It works as expected to do a digital read on the pins for a button push.

Unit CamS3 and MicroPython

l.roca — Thu, 09 Apr 2026 08:07:55 GMT

@kuriko Thanks. How can I do it?

TimerCamera-X and MicroPython

l.roca — Thu, 09 Apr 2026 08:00:13 GMT

Thanks. How can I do it?

M5Stack C6L as Mestastic client, are ports connected to Serial

HappyUser — Tue, 24 Mar 2026 07:34:40 GMT

I was wondering, I have set up the C6L as a Meshtastic client. Works great. Now i want to use G4 and G5 as Serial ports. In the settings of the Mestastic App you can select them. However, i have not been able to setup a serial connection despite different scenarios i tried. With other Mestatstic device i am able to establish a serial connection.
Now my specific question is : does anyone know if G4 and G5 are actually used in the Mestastic software. I just cant find anything?
Thanks

M5Stack C6L: Meshtastic change role

HappyUser — Fri, 13 Mar 2026 09:38:57 GMT

@HappyUser Found it in the Meshtastic app on OSX under device settings. Btw, IOS app does not allow for tcp connections as it seems.

Issue with unit 4 relay on cores3

ngolf — Mon, 09 Mar 2026 17:40:26 GMT

On the cores3 (module connected through port A), I see no devices found on i2c scan when using esphome. It finds OK on the atom-lite.
If using the "Cores3 test" binary from m5stack, I can see the address found on the i2c scan app.

Seeking for a specific unit, .. any ideas

felmue — Fri, 27 Feb 2026 07:52:25 GMT

Hello @HappyUser

just curious, which SIM module did you settle on?

Thanks
Felix

M5Unit C6L Lora initialisation error

HappyUser — Mon, 23 Feb 2026 20:53:27 GMT

@felmue said in M5Unit C6L Lora initialisation error:

here

thank you for figuring that out. Honestly, i would have expected that that would be dealt with in M5Unified. Anyway, module works great. Cam right on time on the market because we really need to upgrade our iot devices in the field.

Unit 8Servos glitching with mixed pin modes

pink0d — Sat, 14 Feb 2026 22:26:48 GMT

Hi!
I'm using Unit 8Servos to control a servo and several RGB leds.
While servo control works OK, when I set some pins to RGB mode, the servo starts glitching. It is also related with how often I call setLEDColor method: more calls cause more glitching on the servo channel.
This issue seems to be not related to power problems: a high power battery with a capacitor are attached directly to the unit.
I'm not familiar with STM32 coding, but it seems that the internal firmware of 8Servos unit has some issues, possibly the timer used to generate the servo pulses is reset on every I2C write.

Internal pull-up support on Unit PbHub / Unit EXT.IO2?

sk-ys — Thu, 05 Feb 2026 12:51:13 GMT

@felmue
Thank you for the clarification.
Yes, it seems that internal pull-up/pull-down resistors cannot be controlled at the moment.
I also checked the documentation, but could not find any way to configure this, which is why I posted the question here.

I hope this feature can be supported in the future, as it would be very useful in practice.

Thanks again for sharing your experience.

Cardputer ADV

felmue — Sat, 31 Jan 2026 14:56:42 GMT

Hello @Mamoulian

thank you for that information. I was not aware the the timers in ESP32S3 are also called RTC timers.

Thanks
Felix

Unit Roller485-Lite U182-Lite

whitecider — Wed, 14 Jan 2026 09:26:08 GMT

Hi,

How can i get a 3d model of this?

Problem with Ultrasonic I2C

ymd_m — Tue, 13 Jan 2026 18:46:44 GMT

@maiknaef Hello.
I have same problem with AtomS3, nanoC6 and Atom lite and Din Meter.
However M5dial works fine. I tested Uiflow2.4.0 and 2.4.1.
It is strange because M5dial and M5Din meter are uses StampS3.
Sorry I have no idea at this moment, however hopefully it solved in future.

M5Unit_Roller CAN Bricked.

cepics — Sat, 10 Jan 2026 10:04:35 GMT

I'm trying to upload a new firmware on the unit roller connecting a ST_Link v2 to the SPI connector with STM32CubeProgrammer.

Roller SPI ---------------- ST_LinkV2 V --------------------- 3.3 G -------------------- GND C ------------------ SWCLOCK D ------------------ SWDIO O ------------------- NC

when the firmware si uploaded the unit roller works (display right boot image and information, led is on, button and encoder works and menu works too), but if I disconnect the SPI cable and I power the unit from grove or dc in 6/16v, the unit doesn't work(black display, led off, etc).

this is the .hex firmware used.

and this is the cube log:

22:11:59 : MASS ERASE ... 22:11:59 : Mass erase successfully achieved 22:11:59 : UPLOADING ... 22:11:59 : Size : 1024 Bytes 22:11:59 : Address : 0x8000000 22:11:59 : Read progress: 22:11:59 : Data read successfully 22:11:59 : Time elapsed during the read operation is: 00:00:00.019 22:12:36 : Opening and parsing file: ROLLERCAN.hex 22:12:36 : Memory Programming ... 22:12:36 : File : ROLLERCAN.hex 22:12:36 : Size : 94.38 KB 22:12:36 : Address : 0x08002000 22:12:36 : Erasing memory corresponding to segment 0: 22:12:36 : Erasing internal memory sectors [4 51] 22:12:37 : Download in Progress: 22:12:39 : File download complete 22:12:39 : Time elapsed during download operation: 00:00:02.735 22:12:39 : Verifying... 22:12:39 : Read progress: 22:12:39 : Time elapsed during verifying operation: 00:00:00.645 22:12:39 : Download verified successfully 22:12:39 : Memory [0x08000000 : 0x08020000] - Checksum : 0x011ED0C0 22:12:39 : RUNNING Program ... 22:12:39 : Address: : 0x08002000 22:12:39 : Application is running, Please Hold on... 22:12:39 : Start operation achieved successfully

this is the log of OB:

{ "deviceId" : 1128, "bitNameToValue" : { "RDP" : 170, "BOR_LEV" : 0, "nRST_STOP" : 1, "nRST_STDBY" : 1, "nRST_SHDW" : 1, "IWDG_SW" : 1, "IWDG_STOP" : 1, "IWDG_STDBY" : 1, "WWDG_SW" : 1, "nBOOT1" : 1, "SRAM_PE" : 1, "CCMSRAM_RST" : 1, "nSWBOOT0" : 1, "nBOOT0" : 1, "NRST_MODE" : 3, "IRHEN" : 1, "PCROP1_STRT" : 16383, "PCROP1_END" : 0, "PCROP_RDP" : 0, "WRP1A_STRT" : 63, "WRP1A_END" : 0, "WRP1B_STRT" : 63, "WRP1B_END" : 0, "SEC_SIZE1" : 0, "BOOT_LOCK" : 0 } }

If I power the unit from grove or DC in, I have 3.3v on SPI (V,G).

I tried to merge and burn a bootloader.hex too but no joy.

after uploading the firmware if I connect the grove cable of an atom lite running a i2c scanner code, I can see 0x64 on serial monitor. I can also disconnect the SPI cable and the roller still works until a power cycle.

ideas??

tnks a lot!!

Brand new Cardputer-ADV fails on first charging.

Jim Horn — Tue, 30 Dec 2025 03:01:55 GMT

Just received my Cardputer-ADV. Turned it on, worked great. Sample software did also, I noticed the battery was 50% charged so plugged in a USB-C charger that I've used for many devices. Immediately got a spark and burning smell while it went dead. No sign of life, off or on. Quite a surprise!

Any suggestions? I hate to wait weeks again for something that might fail so quickly. My earlier Cardputer has had zero problems, but its lack of externally available I/O limited its utility in my work. I'm eager to use the -ADV version once I have one that works.

Thanks to all, including the M5 team!

CO2 from ENV-Pro

robski — Tue, 11 Nov 2025 15:11:39 GMT

from M5Docs:
ENV Pro Unit is an environmental sensor that utilizes the BME688 sensor solution, supporting the measurement of various environmental parameters such as
volatile organic compounds (VOCs),
indoor air quality (IAQ),
temperature, humidity,
and atmospheric pressure.

env pro.JPG

unit hbridget v1.1

Bat21 — Thu, 11 Sep 2025 15:58:58 GMT

@felmue
Thanks for replying. I'm currently using UIFlow2 v2.3.7. If I remove the "GET" commands, as shown in the image, it works without displaying these values, obviously.

I'm using Core Basic with the latest version UIFlow2 v2.3.7. Could that be related?

6427e3b2-595e-4456-a647-1395a76d634d-image.png

But when I add a single "GET" command, this error occurs at startup.

b6971018-763d-4c4a-88ec-fcc4a5f7a333-image.png

0c33d82b-4dd9-4eec-bf80-15af19f49716-image.png

Thanks in advance for replying, I have several open messages and no one is answering.

decoding received Lora P2P messages

adamm5 — Thu, 14 Aug 2025 01:59:53 GMT

well sorted it out by counting characters...however this will break if the preamble data changes length and i can't locate a spec for this protocol.

The UIFlow2 section of the online specs in m5.docs also just says 'coming soon' for UIFlow2....although it does actually exist (albeit undocumented....).

Is there another source for this documentation???

Lora module P2P mode not receiving

adamm5 — Fri, 08 Aug 2025 01:31:40 GMT

@adamm5

Well ChatGPT solved my problem....increasing the spreading factor to 11 has suddenly made everything work. Not sure why such a high SF would be needed between two devices on the same desktop? Will soon find out.

In the meantime, the following table gives some interesting perspective on the transmission time for a 19byte payload.

SF Symbol Duration Payload Symbols Total Symbols Airtime 7 1.024 ms 37 51.25 0.052 s 8 2.048 ms 37 51.25 0.105 s 9 4.096 ms 37 51.25 0.210 s 10 8.192 ms 37 51.25 0.420 s 11 16.384 ms 37 51.25 0.839 s 12 32.768 ms 37 51.25 1.678 s

Roller485-Lite power supply

maby2001 — Sun, 27 Jul 2025 15:09:32 GMT

@kuriko A follow-up question, if I may...

Can an M5Stack controller accept power from the Grove connector? If I connect an Atom-Lite to a Roller485Lite via the I2C port and supply 12V to the Roller485 through the PWR485 port, will this provide power to the Atom-Lite? There appears to be a path through the schematics...

TIA

Martin

How to remove Tab5 battery compartment cover?

robski — Wed, 23 Jul 2025 05:32:01 GMT

press and hold red button then slide it out

How to get Encoder Counter value in I2C Speed Mode for Unit Roller485 Lite (Arduino IDE + M5StickC)

cheng80 — Fri, 04 Jul 2025 04:54:32 GMT

Hi M5Stack team,

I’m currently developing with the M5StickC using the Arduino IDE, and working with the Unit Roller485 Lite module in I2C mode.

I’ve set the module to Speed Mode using RollerI2C.setMode(ROLLER_MODE_SPEED), and tried reading the encoder counter using RollerI2C.getDialCounter().

However, I noticed that the counter value only changes when the module is set to ROLLER_MODE_ENCODER. While in Speed Mode, getDialCounter() always returns the same value, even though the motor is moving.

From the currently available documentation and APIs, I couldn’t find any way to retrieve encoder counter values while in Speed Mode.

My questions are:
1. Is it possible to read the encoder counter value in I2C mode while the motor is operating in Speed Mode?
2. I’m not looking to switch modes dynamically. I would like to read the encoder value independently of the current mode — is this supported?
3. If not currently supported, is there any plan to add this functionality in future firmware or library updates?

Thank you for your support.

M5Stack PoE Camera with Wi-Fi (OV3660) firmware issue

Numpon — Sat, 21 Jun 2025 16:03:29 GMT

I have new M5Stack PoE Camera with Wi-Fi (OV3660).
Update firmware using M5Burner is work well but when I try examples following this documents, all examples are not work.
https://docs.m5stack.com/en/unit/M5PoECAM-W V1.1

I guess library or something is not update. Please help.