diff --git a/arduino/realtek-ambz/cores/arduino/LibreTuyaAPI.cpp b/arduino/realtek-ambz/cores/arduino/LibreTuyaAPI.cpp
new file mode 100644
index 0000000..0b16814
--- /dev/null
+++ b/arduino/realtek-ambz/cores/arduino/LibreTuyaAPI.cpp
@@ -0,0 +1,97 @@
+/* Copyright (c) Kuba Szczodrzyński 2022-05-28. */
+
+#include <LibreTuyaAPI.h>
+
+#include <rtl8710b.h>
+#include <sys_api.h>
+
+void LibreTuya::restart() {
+	sys_reset();
+}
+
+/* CPU-related */
+
+ChipType LibreTuya::getChipType() {
+	uint8_t chipId;
+	EFUSE_OneByteReadROM(9902, 0xF8, &chipId, L25EOUTVOLTAGE);
+	return (ChipType)((RTL8710B << 8) | chipId);
+}
+
+const char *LibreTuya::getChipModel() {
+	return STRINGIFY_MACRO(MCU);
+}
+
+uint32_t LibreTuya::getChipId() {
+	uint32_t chipId = 0;
+	uint8_t *id		= (uint8_t *)&chipId;
+	// 9902 was extracted from ROM disassembly, probably not needed
+	EFUSE_OneByteReadROM(9902, 0x3B, id + 0, L25EOUTVOLTAGE);
+	EFUSE_OneByteReadROM(9902, 0x3C, id + 1, L25EOUTVOLTAGE);
+	EFUSE_OneByteReadROM(9902, 0x3D, id + 2, L25EOUTVOLTAGE);
+	return chipId;
+}
+
+uint8_t LibreTuya::getChipCores() {
+	return 1;
+}
+
+const char *LibreTuya::getChipCoreType() {
+	return "ARM Cortex-M4F";
+}
+
+uint32_t LibreTuya::getCpuFreqMHz() {
+	return CPU_ClkGet(false) / 1000000;
+}
+
+inline uint32_t LibreTuya::getCycleCount() {
+	return microsecondsToClockCycles(micros());
+}
+
+/* Memory management */
+
+uint32_t LibreTuya::getRamSize() {
+	return 256 * 1024;
+}
+
+uint32_t LibreTuya::getHeapSize() {
+	return configTOTAL_HEAP_SIZE;
+}
+
+uint32_t LibreTuya::getFreeHeap() {
+	return xPortGetFreeHeapSize();
+}
+
+uint32_t LibreTuya::getMinFreeHeap() {
+	return xPortGetMinimumEverFreeHeapSize();
+}
+
+uint32_t LibreTuya::getMaxAllocHeap() {
+	return 0;
+}
+
+/* OTA-related */
+
+uint8_t LibreTuya::getOtaRunning() {
+	uint32_t *otaAddress = (uint32_t *)0x8009000;
+	if (*otaAddress == 0xFFFFFFFF)
+		return 1;
+	uint32_t otaCounter = *((uint32_t *)0x8009004);
+	// what the-
+	// "LSB 0 bits number is odd/even"
+	uint8_t count = 0;
+	for (uint8_t i = 0; i < 32; i++) {
+		if ((otaCounter & (1 << i)) == 0)
+			count++;
+	}
+	return 1 + (count % 2);
+}
+
+uint8_t LibreTuya::getOtaTarget() {
+	return getOtaRunning() ^ 0b11;
+}
+
+bool LibreTuya::switchOta() {}
+
+/* Global instance */
+
+LibreTuya LT;
diff --git a/arduino/realtek-ambz/cores/arduino/wiring.c b/arduino/realtek-ambz/cores/arduino/wiring.c
index ebe7bd1..6e8c69b 100644
--- a/arduino/realtek-ambz/cores/arduino/wiring.c
+++ b/arduino/realtek-ambz/cores/arduino/wiring.c
@@ -68,7 +68,7 @@ uint32_t millis(void) {
 uint32_t micros(void) {
 	uint32_t tick1, tick2;
 	uint32_t us;
-	uint32_t tick_per_us = 166666;
+	uint32_t tick_per_us = F_CPU / 1000;
 
 	if (__get_ipsr__() == 0) {
 		tick1 = xTaskGetTickCount();
diff --git a/builder/frameworks/realtek-ambz-sdk.py b/builder/frameworks/realtek-ambz-sdk.py
index 8b4606d..6ac2633 100644
--- a/builder/frameworks/realtek-ambz-sdk.py
+++ b/builder/frameworks/realtek-ambz-sdk.py
@@ -57,7 +57,6 @@ env.Append(
     CPPDEFINES=[
         "M3",
         "CONFIG_PLATFORM_8711B",
-        ("F_CPU", "166000000L"),
         # LwIP options
         ("LWIP_TIMEVAL_PRIVATE", "0"),
         ("LWIP_NETIF_HOSTNAME", "1"),  # to support hostname changing