Posted on June 08, 2016 at 09:05Hello,Here I've got a board hosting a sensor communicatingvia I2C.
The Board is based on a STM32F410RBT***I use the HALdrivers!
below you can find the manual:
http://www.st.com/content/ccc/resource/technical/document/user_manual/2f/71/ba/b8/75/54/47/cf/DM00105879.pdf/files/DM00105879.pdf/jcr:content/translations/en.DM00105879.pdf
onpage 440 ffyou can find the basic Master Transmit andReceive Functions!
For my comprehension (and yours as well ;) :(
The I2C initialization has been done using the STM32CubeMXtool,
that worked quite well and is a very handy tool.
Having a proper initialization I can move straight forwardto access to
the I2C Busand devices attached to it!
In order to get a value from my sensor I should obey thefollowing rules ( I guess):
transmit a value to sensor (sensor's address + register ofsensor to be writtenread from)
then
receive value from sensor (or respectively transmit value dependingon what you want to do)
I did this using the ''polling'' (busy waiting)functions -->
first
call
HAL_I2C_Master_Transmit
then
call
HAL_I2C_Master_Receive
data has been stored to the address the datapointer waspointing to!!!
that worked quite fine for me but now I d like to avoidpolling
so switching to the interrupt functions!!!
then I have to
call
HAL_I2C_Master_Transmit_IT
then
HAL_I2C_Master_Receive_IT''
HAL_I2C_Master_Transmit_IT''
triggers the ISR
HAL_I2C_MasterTxCpltCallback()
when data has been fully sent! Am I right?''
HAL_I2C_Master_Receive_IT''
triggers the ISR
HAL_I2C_MasterRxCpltCallback()
when fully received data! AM I rigt?
Unfortunately Here I can only get ''random'' datafrom the sensor
when just calling the Receive-function!
if using both, no data can be received at all!!
I assume I have to use the I2C ISRs for a nice blockingmechanism.....
like
do not start receive before having transmit and vice versa;
do not start transmit before data of recent call is sent;
do not start receive before data of recent call is received;
Am I right?
Or are those Interrupt I2C functions completely differently
meant to be applied?
kind regards
Oli
