cpu/esp32/include/periph_cpu.h overrides the default definition of adc_res_t from periph/adc with a definition which contains only four resolution, two new resolutions and two resolutions defined by the default definition of adc_res_t. This gives compilation errors if an application uses other resolutions. According to the documentation, adc_sample should return -1 if the resolution is not supported. All other CPUs override adc_res_t either to add new resolutions or to mark resolutions as unsupported. But they all allow to use them at the interface. Therefore, esp32 overrides now the definition of adc_res_t with all resolutions that are defined by the default definition of adc_res_t and new platform specific resolutions. It returns -1 if a resolution is used in adc_sample that is not supported.
By not forcing a fixed oversampling rate we can achieve better baud rate
accuracy than otherwise possible.
For example, when requesting 115200 with a module clock of 4 MHz,
picking an oversampling rate of 17 (instead of hardware
default 16) yields 117647 baud instead of 125000 baud as the best
matching rate. Better matching baud rate between receiver and
transmitter results in a lower probability of transmission errors.
- correct number of timers for atmega328p from 2 to 1
- correct number of timer channels for atmega328p from 3 to 2
- adapt atmega periph timer implementation accordingly
This commit adds the ESP32 vendor libraries for WLAN to the BASELIBS variable. This avoids having to define an additional archive group in the LINKGFLAGS variable which contains these vendor libraries and again RIOT module archive files with the symbols that are refered by these vendor libraries.
Measurements show that the time from pin edge until return from
interrupt is reduced from 22 us to 6.1 us for KW41Z running at
41.94 MHz. The measurements used a no-op GPIO callback for testing and
were measured using an external logic analyzer.
cpu.c and startup.c were redundant in most platforms, except for
atmega256rfr2. The common code is now in cpu/atmega_common/cpu.c
and cpu/atmega_common/startup.c. cpu_conf.h is also removed as
it's now in cpu/atmega_common/include thus shared by all atmega
based platforms.
Removes duplicated code for atmega platforms. They were all
basically the same, only with the exception of atmegarfr2,
for which there is an #if statement to use the code in the
same file.
