From b247dbca97348939aad7a2bcbf4c9df2f495dbc6 Mon Sep 17 00:00:00 2001
From: Francisco Molina <femolina@uc.cl>
Date: Thu, 11 Nov 2021 10:36:33 +0100
Subject: [PATCH] examples/lorawan: use ztimer_msec if not rtc

---
 examples/lorawan/Makefile    |  2 +-
 examples/lorawan/Makefile.ci |  6 ++++++
 examples/lorawan/main.c      | 21 +++++++++++++++++----
 3 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/examples/lorawan/Makefile b/examples/lorawan/Makefile
index 543c4d2ec7..513490347f 100644
--- a/examples/lorawan/Makefile
+++ b/examples/lorawan/Makefile
@@ -27,7 +27,7 @@ USEPKG += semtech-loramac
 
 USEMODULE += $(DRIVER)
 USEMODULE += fmt
-FEATURES_REQUIRED += periph_rtc
+FEATURES_OPTIONAL += periph_rtc
 
 # Comment this out to disable code in RIOT that does safety checking
 # which is not needed in a production environment but helps in the
diff --git a/examples/lorawan/Makefile.ci b/examples/lorawan/Makefile.ci
index 1f1fab2514..4f0caf68cd 100644
--- a/examples/lorawan/Makefile.ci
+++ b/examples/lorawan/Makefile.ci
@@ -1,4 +1,10 @@
 BOARD_INSUFFICIENT_MEMORY := \
+    arduino-duemilanove \
+    arduino-leonardo \
+    arduino-nano \
+    arduino-uno \
+    atmega328p-xplained-mini \
+    atmega328p \
     nucleo-f031k6 \
     nucleo-f042k6 \
     nucleo-l011k4 \
diff --git a/examples/lorawan/main.c b/examples/lorawan/main.c
index 52bc45df10..5a8a5e31b2 100644
--- a/examples/lorawan/main.c
+++ b/examples/lorawan/main.c
@@ -27,7 +27,12 @@
 #include "thread.h"
 #include "fmt.h"
 
+#if IS_USED(MODULE_PERIPH_RTC)
 #include "periph/rtc.h"
+#else
+#include "timex.h"
+#include "ztimer.h"
+#endif
 
 #include "net/loramac.h"
 #include "semtech_loramac.h"
@@ -45,7 +50,7 @@
 #endif
 
 /* Messages are sent every 20s to respect the duty cycle on each channel */
-#define PERIOD              (20U)
+#define PERIOD_S            (20U)
 
 #define SENDER_PRIO         (THREAD_PRIORITY_MAIN - 1)
 static kernel_pid_t sender_pid;
@@ -58,6 +63,9 @@ static sx127x_t sx127x;
 #if IS_USED(MODULE_SX126X)
 static sx126x_t sx126x;
 #endif
+#if !IS_USED(MODULE_PERIPH_RTC)
+static ztimer_t timer;
+#endif
 
 static const char *message = "This is RIOT!";
 
@@ -65,7 +73,7 @@ static uint8_t deveui[LORAMAC_DEVEUI_LEN];
 static uint8_t appeui[LORAMAC_APPEUI_LEN];
 static uint8_t appkey[LORAMAC_APPKEY_LEN];
 
-static void rtc_cb(void *arg)
+static void _alarm_cb(void *arg)
 {
     (void) arg;
     msg_t msg;
@@ -74,12 +82,17 @@ static void rtc_cb(void *arg)
 
 static void _prepare_next_alarm(void)
 {
+#if IS_USED(MODULE_PERIPH_RTC)
     struct tm time;
     rtc_get_time(&time);
     /* set initial alarm */
-    time.tm_sec += PERIOD;
+    time.tm_sec += PERIOD_S;
     mktime(&time);
-    rtc_set_alarm(&time, rtc_cb, NULL);
+    rtc_set_alarm(&time, _alarm_cb, NULL);
+#else
+    timer.callback = _alarm_cb;
+    ztimer_set(ZTIMER_MSEC, &timer, PERIOD_S * MS_PER_SEC);
+#endif
 }
 
 static void _send_message(void)