working nrf source tree

5 files changed, 41 insertions, 2 deletions

diff --git a/nrf528xx/CMakeLists.txt b/nrf528xx/CMakeLists.txt
new file mode 100644
index 0000000..5265fc3
--- /dev/null
+++ b/nrf528xx/CMakeLists.txt
@@ -0,0 +1,7 @@
+cmake_minimum_required(VERSION 3.20.0)
+
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(NONE)
+
+target_sources(app PRIVATE src/main.c)
+
diff --git a/nrf528xx/main.c b/nrf528xx/main.c
deleted file mode 100644
index e69de29..0000000
--- a/nrf528xx/main.c
+++ /dev/null
diff --git a/nrf528xx/prj.conf b/nrf528xx/prj.conf
new file mode 100644
index 0000000..91c3c15
--- /dev/null
+++ b/nrf528xx/prj.conf
@@ -0,0 +1 @@
+CONFIG_GPIO=y
diff --git a/nrf528xx/readme.md b/nrf528xx/readme.md
index 77ea509..c54c54e 100644
--- a/nrf528xx/readme.md
+++ b/nrf528xx/readme.md
@@ -1,4 +1,22 @@
 # nrf528xx subdirectory
 
-- compatible with nrf52833 and nrf52840
-- west for building and flashing
+## building
+
+```bash
+# build for big dev board
+west build -b nrf52833dk_nrf52833
+
+# build for usb dongle
+west build -b nrf52840dongle_nrf52840
+```
+
+## flashing
+
+```bash
+# incremental flash
+west flash
+
+# force erase flash first
+west flash --erase
+```
+
diff --git a/nrf528xx/src/main.c b/nrf528xx/src/main.c
new file mode 100644
index 0000000..649af38
--- /dev/null
+++ b/nrf528xx/src/main.c
@@ -0,0 +1,13 @@
+#include <zephyr/zephyr.h>
+#include <zephyr/drivers/gpio.h>
+
+static const struct gpio_dt_spec led = GPIO_DT_SPEC_GET(DT_ALIAS(led0), gpios);
+
+void main() {
+  gpio_pin_configure_dt(&led, GPIO_OUTPUT_ACTIVE);
+
+  while (1) {
+    gpio_pin_toggle_dt(&led);
+    k_msleep(1000);
+  }
+}