[ISSUE-44]: example app for examining recurrent alarms

Author: SzigetiJ

configure.ac

@@ -18,6 +18,7 @@ AC_CONFIG_SUBDIRS([examples])
 AC_CONFIG_SUBDIRS([examples/0blink])
 AC_CONFIG_SUBDIRS([examples/0hello])
 AC_CONFIG_SUBDIRS([examples/0ledctrl])
+AC_CONFIG_SUBDIRS([examples/0timgalarm])
 AC_CONFIG_SUBDIRS([examples/0uart])
 AC_CONFIG_SUBDIRS([examples/0udma])
 AC_CONFIG_SUBDIRS([examples/1i2cssd1306])
@@ -39,6 +40,7 @@ AC_CONFIG_FILES([
   examples/0button/Makefile
   examples/0hello/Makefile
   examples/0ledctrl/Makefile
+  examples/0timgalarm/Makefile
   examples/0uart/Makefile
   examples/0udma/Makefile
   examples/1i2cssd1306/Makefile

examples/0timgalarm/Makefile.am

@@ -0,0 +1,36 @@
+include $(top_srcdir)/scripts/elf2bin.mk
+include $(top_srcdir)/ld/flags.mk
+
+noinst_HEADERS = defines.h
+
+if WITH_BINARIES
+AM_LDFLAGS += \
+ -T $(top_srcdir)/ld/esp32.rom.ld \
+ -T $(top_srcdir)/ld/esp32.rom.libgcc.ld \
+ -T $(top_srcdir)/ld/esp32.rom.newlib-data.ld \
+ -T $(top_srcdir)/ld/esp32.rom.newlib-locale.ld \
+ -T $(top_srcdir)/ld/esp32.rom.newlib-nano.ld \
+ -T $(top_srcdir)/ld/esp32.rom.newlib-time.ld \
+ -T $(top_srcdir)/ld/esp32.rom.redefined.ld \
+ -T $(top_srcdir)/ld/esp32.rom.syscalls.ld
+else
+AM_LDFLAGS += \
+ -T $(top_srcdir)/ld/esp32.rom.ld \
+ -T $(top_srcdir)/ld/esp32.rom.libgcc.ld \
+ -T $(top_srcdir)/ld/esp32.rom.redefined.ld \
+ -T $(top_srcdir)/ld/esp32.rom.syscalls.ld
+endif
+
+AM_CFLAGS  = -std=c11 -flto
+AM_CPPFLAGS = -I$(top_srcdir)/src -I$(srcdir)
+LDADD = $(top_builddir)/src/libesp32basic.a
+
+bin_PROGRAMS = \
+ alarm.elf
+
+if WITH_BINARIES
+CLEANFILES = \
+ alarm.bin
+endif
+
+BUILT_SOURCES = $(CLEANFILES)

examples/0timgalarm/README.md

@@ -0,0 +1,15 @@
+### Measuring TIMG alarm accuracy
+
+This example examines periodic TIMG alarm behaviour for very low alarm values.
+
+#### Control
+
+* `1`,`2`, `3` selects `timer0_1`,`timer1_0` or `timer1_1` for measurement.
+* `a`,`b` selects how to implement recurrency: `a` for timer autoreload, `b` for incrementing `ALARM` value of the timer.
+* `[`,`]` for decrease/increase sampling length by `1`.
+* `{`,`}` for decrease/increase sampling length by `10`.
+* `,`,`.` for decrease/increase alarm period by `1`.
+* `<`,`>` for decrease/increase alarm period by `10`.
+* `s` starts the measurement.
+* `r` prints the result of the last measurement.
+* `c` prints some register information for debugging.