Changing MAG3110-I²C Address

[rl1]

Hi, I'm trying to use more then one MAG3110 in an I²C-sensor-Network. Is it possible to change the I²C address from the device? The sensor manual describes only, that the standard address is 0x0E. Thanks for help.

rl1

[DavidS]

Hi rl1,

Are you connecting up to a Kinetis MCU?

Many Kinetis L and K MCU’s have more than one I2C interface so you could connect one up to each.

Just an idea.

Regards,

David

[rl1]

Hi David,

thank you for your answer. But the application needs 25 up to 200 sensor modules. Theese modules are geometrically distributed over 500m. The idea was to design very low power modules which are connected to a large sensor network through I²C bridges/repeaters. The design of one modul should be the same for all modules.

Regards,

rl1

[reyes]

Hi Ronny Lettke,

Unfortunately this device address cannot be changed, actually for our customers who plan to use 2 or more MAG3110 in their applications we recommend them to use an i2c multiplexer.

Sorry about the issues that this may cause.

Another option it’s to change from the MAG3110 to the FXOS8700, using this device you can get up to 4 different slave addresses, the slave addresses that may be assigned to the FXOS8700CQ part are 0x1C, 0x1D, 0x1E, or 0x1F. The selection is made through the logic level of the SA1 and SA0 inputs pins.

Have a great day,
Jose Reyes

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[rl1]

Hi Jose Reyes,

thanks for your answer.

My application has to realize 25sensor- up to 200 sensor- modules.

So, if it is a point of financial view to realize, that the address of the device can be changed, so let me know it.

Thank you for the help.

rl1

[reyes]

Hi rl1,

Customers cannot do this address change directly with some registers or pins configurations, but this could be done on fabric for big orders. Is not easy to generate devices with non-standard IIC addresses, this is why this can only be done in fabric, for big orders and still would take too long to take this order, and probably more in your particular case since, if I understand correctly, you would need 25 to 200 different device addresses (I’m not sure if this is even possible since it’s a 7-bit address device, therefore only 128 possible numbers allowed).

You would need to contact your Freescale Sales Representative directly in order to try to do this.

Other solution would be to use a mcu (kinetis for example) as a “sensor hub” than can have multiple I2C buses and mount up to four FXOS8700 on each bus.

For example let say that you have a kinetis mcu (as a “sensor hub”) with three I2C buses, one of them (I2C1) is used to communicate this sensor hub with the Master mcu, and you have two I2C buses (I2C2 and I2C3) available to connect four FXOS8700 on each bus, so you can get up to eight sensors for each sensor hub on this particular example. So for a case where you need 40 sensors connected, you would need 1 master mcu and 5 “sensor hub” mcus.

Have a great day,
Jose Reyes

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