When writting or reading a block, if the block doesn't fit the area where it begins, the next base address is always zero. Thus the calculations to define the next value of addr are unnecessary.
Here's a quick validity proof using the previous calculations:
First: Considering the case where the block doesn't fit it's first area:
That means that (count + addr > length), what makes:
count = length - addr; (1)
So the following operations:
addr += count;
addr -= length;
Are the same as doing:
addr = addr + count - length; (2)
Using (1) and (2) we have:
addr = addr + length - addr - length = 0
Second: When the block fits the area where it's at:
That means that variable count is not changed,
thus (n -= count) evaluates to 0, which makes the loop exit.
Another change was (b += count;) being moved after the condition to break the loop, since we just need to move the block pointer when it doesn't fit the first area.
remove PANICs from init
return semaphore if init fails
add successful initialisation check before attempting to read from sensor
structure made private where possible
formatting fixes
check I2C reads succeed
add request_measurement to request sensor to produce measurement
quit after 20 of previous 40 reads fail
throttle reads to 10hz max
Fixed this bug
https://github.com/diydrones/ardupilot/issues/840
If a Rover was in AUTO and the user moved the throttle stick into
reverse past 50% the rover would increase. Basically the throttle
nudge behaviour was the same regardless of whether you moved the
throttle forward or backward.
In case of error or zeroed data, the i2c semaphore wasn't given.
It happened at first startup on Bebop and caused a failure:
"PANIC: failed to take _bus->sem 100 times in a row..."
If someone mistakenly puts all 0's in their LAND command then
total_distance will be calculated as 0 and cause a divide by 0 error
below thus crashing ArduPilot. Lets avoid that.
When the rover goes into guided mode it sets the current location as
the guided point to goto. If the rover is stationary when this
happens no problem. If however the rover is still rolling (say going
from AUTO to GUIDED) then the rover would go past its guided position
and get confused and begin to circle it. This change resolves that issue.
