HMC5883L Magnetometer

I guess your code was originally meant for the 4843 in which the read pointer would wrap around after 9 reads.

To minimize the communication between the master and this device, the address pointer updated automatically without master intervention. This automatic address pointer update has two additional features. First when address 12 or higher is accessed the pointer updates to address 00 and secondly when address 09 is reached, the pointer rolls back to address 03. Logically, the address pointer operation functions as shown below.

If (address pointer = 09) then address pointer = 03
Else if (address pointer >= 12) then address pointer = 0
Else (address pointer) = (address pointer) + 1

but for the 4883 the read pointer would wrap around after 8 reads.

To minimize the communication between the master and this device, the address pointer updated automatically without master intervention. This automatic address pointer update has two additional features. First when address 12 or higher is accessed the pointer updates to address 00 and secondly when address 08 is reached, the pointer rolls back to address 03. Logically, the address pointer operation functions as shown below.

If (address pointer = 08) then address pointer = 03
Else if (address pointer >= 12) then address pointer = 0

Else (address pointer) = (address pointer) + 1

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Randy November 15, 2011 at 6:22am

I guess your code was originally meant for the 4843 in which the read pointer would wrap around after 9 reads.

To minimize the communication between the master and this device, the address pointer updated   automatically without master intervention. This automatic address pointer update has two additional features. First when address 12 or higher is accessed the pointer updates to address 00 and secondly when address 09 is reached, the pointer rolls back to address 03. Logically, the address pointer operation functions as shown below.

If (address pointer = 09) then address pointer = 03
Else if   (address pointer >= 12) then address pointer = 0
Else (address pointer)   = (address pointer) + 1

but for the 4883 the read pointer would wrap around after 8 reads.

To minimize the communication between   the master and this device, the address pointer updated automatically without   master intervention. This automatic address pointer update has two additional   features. First when address 12 or higher is accessed the pointer updates to   address 00 and secondly when address 08 is reached, the pointer rolls back to address   03. Logically, the address pointer operation functions as shown below.

If (address   pointer = 08) then address pointer   = 03
Else if (address pointer >= 12) then address pointer =   0

Else (address pointer) = (address pointer) +   1

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HMC5883L Magnetometer

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