- uart->available(); returns uint32 but was stored locally as int32 and treated as uint32. Now stored correctly as uint32
- some variables were set to zero at start of function, then reset to zero before being used. wasted work
Having a critical divide by value as a class member that could change external to the function using it is fragile. It was not very obvious that a divide by zero was not possible in the current design, now it's very obvious and safer in case the code changes later.
- Most of the boards use bus 1 for first I2C
- If the bus doesn't exist, let the detect() method fail when it
call start_reading(), because _dev would be invalid
This rangefinder uses an spi device to send pulses and an iio driver
in buffer mode to get data
The data is then analyzed and the maximum pulse received is considered to
represent the echo of the pulses that have been sent. The distance in time
between the pulse that is sent and the pulse with the maximum amplitude
is used to calculate the altitude based on the speed of sound.
There is a dependency with libiio, and in order to build, there is a need
to provide a rootfs that includes libiio.a.
The other solution is to build dynamically after having updated the rootfs
to use on compiled with a more recent toolchain and include libiio
This adds .data section loading to the HC-SR04 range finder driver used by
BBBMINI. The firmware is running inside a PRU. It is necessary to develop more
complex driver software inside the PRU.
The problem with using min() and max() is that they conflict with some
C++ headers. Name the macros in uppercase instead. We may go case by
case later converting them to be typesafe.
Changes generated with:
git ls-files '*.cpp' '*.h' -z | xargs -0 sed -i 's/\([^_[:alnum:]]\)max(/\1MAX(/g'
git ls-files '*.cpp' '*.h' -z | xargs -0 sed -i 's/\([^_[:alnum:]]\)min(/\1MIN(/g'
Now variables don't have to be declared with PROGMEM anymore, so remove
them. This was automated with:
git grep -l -z PROGMEM | xargs -0 sed -i 's/ PROGMEM / /g'
git grep -l -z PROGMEM | xargs -0 sed -i 's/PROGMEM//g'
The 2 commands were done so we don't leave behind spurious spaces.
AVR-specific places were not changed.
