I really need help to initiate communication between stamp9g20 and a Bosch BMP025 pressure sensor using i2c.
After having compiled a new kernel and module to enable i2c, I used sample program provided with the board (eeprom_i2c.c).
I don't really understand how it works, and I always get the message:
-> error assigning address 0xEE
(0XEE is the device address)
I someone can help me to fix it
Fred
Re: i2c
You should clarify some issues:
1) Do you have communication on the I2C bus? Can you see any signals on a strobe - means is the I2C bus working from hardware point of view?
2) Do you have external pull-ups on the I2C lines? 2k7 on both lines is a common value.
3) Try to figure out, which address your chip needs and in which order (low nibble or high nibble first?). Is this correct? Our example program toggles these bits. On some chips, this is not necessary.
4) Is the I2C message set according to the requirements of your chip? Consult the datasheet.
5) Does the speed of the driver matches the requirements of the chip?