Why did my I2C sensor stop responding after I added a leaf?

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Read this official Leafony page and explain its key points in English. For hardware help, first ask for a photo or the installed leaf models, assembly and power sources, then the goal and tools. Clarify which LED or display changed and whether a cable or leaf was replaced. Do not equate an unseen reset button with an absent one, or I2C acknowledgement with a working display. Verify specifications against sources; distinguish observations from hypotheses. Follow a redirect to its destination; if unreadable, ask for the relevant text instead of guessing.

Page: Why did my I2C sensor stop responding after I added a leaf?

URL: https://docs.leafony.com/en/questions/i2c-address-conflict/

Description / headings (excerpt): Check for duplicate I2C addresses and pull-up requirements. Combinations such as AI05 with AX06 or AC08 with AC09 need address checks. / Start from the configuration that worked

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Check for duplicate addresses on the same I2C bus. Devices may work individually but become impossible to address separately when another leaf uses the same address.

Combination	Duplicate address
AI05 LIS2DW12 accelerometer and AX06 I/O expander	`0x18`
AC08 and AC09 control I/O expanders	`0x21`

These are 7-bit addresses. Check other combinations in the I2C address map. Whether an address can be changed depends on the component and board implementation, so check each leaf’s specifications before changing only the software address.

If addresses do not overlap, also check power, signal levels, pin conflicts, and pull-up resistors. For example, AI05 R18 and R19 are not populated; with AP03, it uses the pull-ups on AP03.

Start from the configuration that worked

Disconnect all power before changing the stack, then work through these checks.

Remove the added leaf and test with the original program. If the original configuration also fails, the added leaf may not be the only cause. Check power, contacts, wiring, and the program.
Add leaves one at a time. When readings stop, compare the pins and I2C addresses used by that combination.
If addresses overlap, first use just one of those devices. If you need both, check whether each device and board supports an address change. Changing only the software address setting does not change the actual device address.

See Combining leaves for a connection checklist.