SensorsのトピックRe: MPL3115A2 fail

MPL3115A2 fail

alexanderkobzev — Tue, 03 Feb 2026 22:03:17 GMT

I use MPL3115A2 (M3PR YI0C) to measure temperature, pressure and elevation. Periodically change the mode of the altimeter to barometer mode and Vice versa. I ran into the following problem: After some time of operation, the STATUS register (0x00) stops updating and becomes always equal to 0x00. Registers the altitude/pressure and temperature (0x01 - 0x05) are set to zero. While reading the configuration registers shows that MPL3115A2 configured true.

Here is an example of registers in a single measurement prior to the crash:

STATUS: 0x0e

OUT P_MSB: 0x61

OUT_P_CSB: 0xa0

OUT_P_LSB: 0xd0

OUT_T_MSB: 0x1a

OUT_T_LSB: 0x50

SYSMOD: 0x01

INT_SOURCE: 0x00

PT_DATA_CFG: 0x07

CTRL_REG1: 0x39

CTRL_REG2: 0x00

CTRL_REG3: 0x00

CTRL_REG4: 0x00

CTRL_REG5: 0x00

Here is the first failed measurement:

STATUS: 0x00

OUT P_MSB: 0x61

OUT_P_CSB: 0xa0

OUT_P_LSB: 0xd0

OUT_T_MSB: 0x1a

OUT_T_LSB: 0x50

SYSMOD: 0x01

INT_SOURCE: 0x00

PT_DATA_CFG: 0x07

CTRL_REG1: 0x39

CTRL_REG2: 0x00

CTRL_REG3: 0x00

CTRL_REG4: 0x00

CTRL_REG5: 0x00

Here are 10 unsuccessful measurement (with attempt to switch mode):

STATUS: 0x00

OUT P_MSB: 0x00

OUT_P_CSB: 0x00

OUT_P_LSB: 0x00

OUT_T_MSB: 0x00

OUT_T_LSB: 0x00

SYSMOD: 0x01

INT_SOURCE: 0x00

PT_DATA_CFG: 0x07

CTRL_REG1: 0xb9

CTRL_REG2: 0x00

CTRL_REG3: 0x00

CTRL_REG4: 0x00

CTRL_REG5: 0x00

The problem appears both when using the interrupt, and when using polling. The only way to MPL3115A2 return to normal operation is a software reboot. What could be the problem?

(Sorry for translate)

Re: MPL3115A2 fail

anthonyduhamel — Fri, 06 Nov 2015 10:19:04 GMT

Hi Alexander,

I'm not sure to answer the question but did you put the MPL3115A2 to Standby mode before switching the mode? It could be a problem.

Can you share with us your code? I'd like to check your configuration.

Thanks

Anthony

Re: MPL3115A2 fail

alexanderkobzev — Fri, 06 Nov 2015 12:02:55 GMT

Hi Anthony!

Thanks for answer!

I use my own driver for MPL3115A2. The driver source code in attachment.

And so I use it:

// ...

mpl3115a2_init( &mpl3115a2 );

mpl3115a2_set_pwrmode( &mpl3115a2, MPL3115A2_PWRMODE_STANDBY );

mpl3115a2_set_ready_mode(

&mpl3115a2,

MPL3115A2_READY_MODE_POLLING );

mpl3115a2_set_mode(

&mpl3115a2,

MPL3115A2_MODE_ALTIMETER,

MPL3115A2_OSR_128 );

mpl3115a2_set_pt(

&mpl3115a2,

MPL3115A2_PT_DREM |

MPL3115A2_PT_PDEFE |

MPL3115A2_PT_TDEFE );

mpl3115a2_set_pwrmode( &mpl3115a2, MPL3115A2_PWRMODE_ACTIVE );

// ...

while ( 1 ) {

// ...

dev_res = mpl3115a2_update( &mpl3115a2 );

dev_res = mpl3115a2_get_h( &mpl3115a2, &data->alt, NULL );

dev_res = mpl3115a2_get_t( &mpl3115a2, &data->temp, &data->temp_l );

dev_res = mpl3115a2_get_p( &mpl3115a2, &data->ph, &data->pl );

// ...

// (In timer-counter value of 'mode_change' increment)

if ( mode_change >= 50 ) {

if ( mpl3115a2.mode == MPL3115A2_MODE_ALTIMETER ) {

mpl3115a2_set_pwrmode( &mpl3115a2, MPL3115A2_PWRMODE_STANDBY );

mpl3115a2_set_mode( &mpl3115a2, MPL3115A2_MODE_BAROMETER, MPL3115A2_OSR_128 );

mpl3115a2_set_pwrmode( &mpl3115a2, MPL3115A2_PWRMODE_ACTIVE );

}

else {

mpl3115a2_set_pwrmode( &mpl3115a2, MPL3115A2_PWRMODE_STANDBY );

mpl3115a2_set_mode( &mpl3115a2, MPL3115A2_MODE_ALTIMETER, MPL3115A2_OSR_128 );

mpl3115a2_set_pwrmode( &mpl3115a2, MPL3115A2_PWRMODE_ACTIVE );

}

mode_change = 0;

}

// ...

// And sleep at 1 - 2 sec...

//...

//Restore after fail

#if MPL3115A2_DEBUG

if ( mpl3115a2_get_fail_count( &mpl3115a2 ) > 11 ) {

mpl3115a2_reset( &mpl3115a2 );

mpl3115a2_set_pt(

&mpl3115a2,

MPL3115A2_PT_DREM |

MPL3115A2_PT_PDEFE |

MPL3115A2_PT_TDEFE );

mpl3115a2_set_pwrmode( &mpl3115a2, MPL3115A2_PWRMODE_ACTIVE );

mpl3115a2_fail_count_clear( &mpl3115a2 );

}

#endif

}

Re: MPL3115A2 fail

anthonyduhamel — Mon, 09 Nov 2015 15:47:10 GMT

Thanks Alexander for sharing,

I have taken a quick look on your source code. I did not spot any specific problem. If I have time, I'll check that in detail. If anybody has the answer, do not hesitate to reply.

Thanks,

Anthony

Re: MPL3115A2 fail

reyes — Tue, 19 Jan 2016 20:46:45 GMT

Hi Alexander,

I checked your source code and I didn't see anything that could cause the problem you are mentioning.

Can I asked if you found the source of your problem? If you did, can you share it, please?

If not, please let me know if there are further details from the mentioned in the community.

Regards,

Jose

Re: MPL3115A2 fail

waynesoutter — Tue, 07 Jun 2016 12:50:23 GMT

We also encountered this issue. After extensive testing, we didn't manage to resolve it, but we found a work around. It was to "software reset" (Search for RST in datasheet) the device in the initialise routine.

mpl3115a2_write(MPL3115A2_CTRL_REG1,0b00000100);

Hope this helps.

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