STC3115 I2C SLAVE DETECTION ISSUE

[chandanprasadn]

Posted on April 15, 2016 at 17:06

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Hi,I am currently working on STC3115.I am facing problem with it.The slave i mean STC3115 is not getting detected when i do i2c test.My platform is linux.I have checked the voltage levels,itseems all are fine.SDA and SCL lines have been pulled up.RSTIO pin is pulled up.BATD/CD is grounded through 1k resister since we are not using it.VIN has been supplied from the battery and VCC has been supplied from regulator.I could not figure out any problems with my hardware connections.Please guide me if i need to do any changes with my hardware so that STC3115 gets detected when i probe for its slave address.Will be waiting for your rply #stc3115-i2c-issue-timing

[Gregory Go.]

Posted on September 24, 2016 at 11:35

This general I2C issue can appear for several reasons:

- STC3115 power supply voltage is too low (must have VCC > 2.7V)- The I2C Slave Address is not correct. Thus the gas gauge do not respond to another address.The correct address is: #define STC3115_SLAVE_ADDRESS_7BIT 0x70 #define STC3115_SLAVE_ADDRESS_8BIT 0xE0- The Setup time and Hold time of I2C specification are not respected.In case of violation the I2C timing, the device won't decode the I2C signal.Check the datasheet requirement constrains for I2C.- The rising edge and falling edge of both I2C signals (SCL and SDA) occur at the same time, without a delay in between.This violate the I2C timing. Thus the STC3115 could miss one rising edge.Adjust the signals of the I2C master device to get a small delay between both rising/falling edge of SCL and SDA signals.Regards