jajn HA

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9 years ago.

ADXL345 problem

Thanks for watching my question! i use ADXL345 (I2C) and my board is LPC4088 i have some problems. this is the ADXL345.cpp and .h. i use below https://developer.mbed.org/users/gltest26/code/ADXL345/file/122a504fcfa3/ADXL345.cpp

this is my code /media/uploads/david8251/10.png /media/uploads/david8251/8.png

and the putty always display /media/uploads/david8251/3.png

what's wrong? thanks

1 Answer

Sanjiv Bhatia
9 years ago.

/media/uploads/juthi/adxl345.png A few ideas:

1) Do you have the required pull-up resistors for the I2C lines ? The value for the resistors is not critical and can be 2k to 10k for each but are required for I2C interfacing.

2) Assuming you have the pull-up resistors, check your ID for this target sensor. From a quick search, the ID for this sensor in your code does not match what other developers are using.

See here:

// read or write bytes
#define ADXL345_I2C_READ    0xA7  
#define ADXL345_I2C_WRITE   0xA6 
#define ADXL345_I2C_ADDRESS 0x53   //the ADXL345 7-bit address is 0x53 when ALT ADDRESS is low as it is on the sparkfun chip: when ALT ADDRESS is high the address is 0x1D
 
/////////////when ALT ADDRESS pin is high:
//#define ADXL345_I2C_READ    0x3B   
//#define ADXL345_I2C_WRITE   0x3A
//#define ADXL345_I2C_ADDRESS 0x1D

Reference: https://developer.mbed.org/users/peterswanson87/code/ADXL345_I2C/

If you continue to have problems, then post more details of your wiring diagram and schematic if available for this sensor.

Accepted Answer

i finish~ but i have another question. i will post later THX very much

posted by jajn HA 01 Nov 2016