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[Bug] A16v3 KCS 3.27.2 - SHT30/SHT31 fails after software reboot - Printable Version

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+--- Thread: [Bug] A16v3 KCS 3.27.2 - SHT30/SHT31 fails after software reboot (/showthread.php?tid=9872)

[Bug] A16v3 KCS 3.27.2 - SHT30/SHT31 fails after software reboot - rokrok - 10-16-2026

I found a reproducible problem with an SHT30/SHT31 sensor on KC868-A16v3 running KCS v3.27.2.
Hardware:
  • KC868-A16v3
  • KCS v3.27.2
  • KinCony SHT30 temperature/humidity sensor
  • I2C address 68 decimal (0x44)
Problem:
After a complete 12 V power cycle, the SHT30 works immediately and temperature/humidity values are displayed normally.
However, if I use Reboot from the KCS web interface, the sensor stops working.
The application log then shows:
Code:
i2c.master: I2C transaction unexpected nack detected
i2c.master: s_i2c_synchronous_transaction(872): I2C transaction failed
i2c.master: i2c_master_transmit(1074): I2C transaction failed
sensor: sht31 error, id=0
KCS retries the sensor, but it may remain unavailable.
How to reproduce:
  1. Power off the whole A16v3 (12 V supply).
  2. Power it on again.
  3. SHT30 data appears immediately and works normally.
  4. In the KCS web interface select Reboot.
  5. After the reboot the SHT30 is no longer available and the log reports I2C NACK / sht31 error.
  6. Remove 12 V power completely and power the A16v3 again.
  7. SHT30 works immediately again.
I have tested this with two different SHT30 sensors.
Initially one sensor had an extended cable, so I suspected the I2C cable length. I then tested a second SHT30 with its original unmodified cable, and it failed immediately after the first KCS software reboot in exactly the same way.
Therefore the cable extension is not the cause.
A complete power cycle of the A16v3/sensor consistently restores operation, while a KCS software reboot can cause the sensor to fail.
It looks like the SHT30/I2C bus or sensor is not being correctly reset/reinitialized after an ESP32 software reboot.
Could you please reproduce this with an A16v3 + SHT30 and check the sensor/I2C initialization after software reboot?

RE: [Bug] A16v3 KCS 3.27.2 - SHT30/SHT31 fails after software reboot - admin - 10-17-2026

we will check ,when have news will feedback at here.