diff --git a/stmhal/Makefile b/stmhal/Makefile
index 064db23c352065aadb61ad8152f15f23898d0876..97891899463511156cd42692e647009350ece647 100644
--- a/stmhal/Makefile
+++ b/stmhal/Makefile
@@ -77,8 +77,9 @@ SRC_C = \
 	pyexec.c \
 	help.c \
 	input.c \
-	modpyb.c \
 	modos.c \
+	modpyb.c \
+	modstm.c \
 	modtime.c \
 	import.c \
 	lexerfatfs.c \
diff --git a/stmhal/modstm.c b/stmhal/modstm.c
new file mode 100644
index 0000000000000000000000000000000000000000..5e72a75bb2da5a97351f87fee833c0e35a1df248
--- /dev/null
+++ b/stmhal/modstm.c
@@ -0,0 +1,120 @@
+#include <stdio.h>
+#include <stdint.h>
+
+#include <stm32f4xx_hal.h>
+
+#include "nlr.h"
+#include "misc.h"
+#include "mpconfig.h"
+#include "qstr.h"
+#include "obj.h"
+#include "modstm.h"
+
+STATIC uint32_t get_read_addr(mp_obj_t addr_o, uint align) {
+    uint32_t addr = mp_obj_get_int(addr_o) & 0x7fffffff;
+    if (addr < 0x10000000) {
+        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "cannot read from address %08x", addr));
+    }
+    if ((addr & (align - 1)) != 0) {
+        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "address %08x is not aligned to %d bytes", addr, align));
+    }
+    return addr;
+}
+
+STATIC uint32_t get_write_addr(mp_obj_t addr_o, uint align) {
+    uint32_t addr = mp_obj_get_int(addr_o) & 0x7fffffff;
+    if (addr < 0x10000000) {
+        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "cannot write to address %08x", addr));
+    }
+    if ((addr & (align - 1)) != 0) {
+        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "address %08x is not aligned to %d bytes", addr, align));
+    }
+    return addr;
+}
+
+STATIC mp_obj_t stm_read8(mp_obj_t addr) {
+    uint32_t a = get_read_addr(addr, 1);
+    uint32_t v = *(uint8_t*)a;
+    return mp_obj_new_int(v);
+}
+
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(stm_read8_obj, stm_read8);
+
+STATIC mp_obj_t stm_read16(mp_obj_t addr) {
+    uint32_t a = get_read_addr(addr, 2);
+    uint32_t v = *(uint16_t*)a;
+    return mp_obj_new_int(v);
+}
+
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(stm_read16_obj, stm_read16);
+
+STATIC mp_obj_t stm_read32(mp_obj_t addr) {
+    uint32_t a = get_read_addr(addr, 4);
+    uint32_t v = *(uint32_t*)a;
+    return mp_obj_new_int(v);
+}
+
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(stm_read32_obj, stm_read32);
+
+STATIC mp_obj_t stm_write8(mp_obj_t addr, mp_obj_t val) {
+    uint32_t a = get_write_addr(addr, 1);
+    uint32_t v = mp_obj_get_int(val);
+    *(uint8_t*)a = v;
+    return mp_const_none;
+}
+
+STATIC MP_DEFINE_CONST_FUN_OBJ_2(stm_write8_obj, stm_write8);
+
+STATIC mp_obj_t stm_write16(mp_obj_t addr, mp_obj_t val) {
+    uint32_t a = get_write_addr(addr, 2);
+    uint32_t v = mp_obj_get_int(val);
+    *(uint16_t*)a = v;
+    return mp_const_none;
+}
+
+STATIC MP_DEFINE_CONST_FUN_OBJ_2(stm_write16_obj, stm_write16);
+
+STATIC mp_obj_t stm_write32(mp_obj_t addr, mp_obj_t val) {
+    uint32_t a = get_write_addr(addr, 4);
+    uint32_t v = mp_obj_get_int(val);
+    *(uint32_t*)a = v;
+    return mp_const_none;
+}
+
+STATIC MP_DEFINE_CONST_FUN_OBJ_2(stm_write32_obj, stm_write32);
+
+STATIC const mp_map_elem_t stm_module_globals_table[] = {
+    { MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_stm) },
+
+    { MP_OBJ_NEW_QSTR(MP_QSTR_read8), (mp_obj_t)&stm_read8_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_read16), (mp_obj_t)&stm_read16_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_read32), (mp_obj_t)&stm_read32_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_write8), (mp_obj_t)&stm_write8_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_write16), (mp_obj_t)&stm_write16_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_write32), (mp_obj_t)&stm_write32_obj },
+
+    { MP_OBJ_NEW_QSTR(MP_QSTR_GPIOA), MP_OBJ_NEW_SMALL_INT(GPIOA_BASE) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_GPIOB), MP_OBJ_NEW_SMALL_INT(GPIOB_BASE) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_GPIOC), MP_OBJ_NEW_SMALL_INT(GPIOC_BASE) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_GPIOD), MP_OBJ_NEW_SMALL_INT(GPIOD_BASE) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_GPIO_IDR), MP_OBJ_NEW_SMALL_INT(0x10) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_GPIO_BSRRL), MP_OBJ_NEW_SMALL_INT(0x18) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_GPIO_BSRRH), MP_OBJ_NEW_SMALL_INT(0x1a) },
+};
+
+STATIC const mp_obj_dict_t stm_module_globals = {
+    .base = {&mp_type_dict},
+    .map = {
+        .all_keys_are_qstrs = 1,
+        .table_is_fixed_array = 1,
+        .used = sizeof(stm_module_globals_table) / sizeof(mp_map_elem_t),
+        .alloc = sizeof(stm_module_globals_table) / sizeof(mp_map_elem_t),
+        .table = (mp_map_elem_t*)stm_module_globals_table,
+    },
+};
+
+const mp_obj_module_t stm_module = {
+    .base = { &mp_type_module },
+    .name = MP_QSTR_stm,
+    .globals = (mp_obj_dict_t*)&stm_module_globals,
+};
diff --git a/stmhal/modstm.h b/stmhal/modstm.h
new file mode 100644
index 0000000000000000000000000000000000000000..205cdd2a189db63b15c146a2bcefa6e0130e8907
--- /dev/null
+++ b/stmhal/modstm.h
@@ -0,0 +1 @@
+extern const mp_obj_module_t stm_module;
diff --git a/stmhal/mpconfigport.h b/stmhal/mpconfigport.h
index 08ba923e405f7e1cf1c0b5b91c1a383866ca4e0f..5529101425fdd23e694f649bef1982ae1243dae5 100644
--- a/stmhal/mpconfigport.h
+++ b/stmhal/mpconfigport.h
@@ -31,12 +31,19 @@ extern const struct _mp_obj_fun_native_t mp_builtin_open_obj;
 // extra built in modules to add to the list of known ones
 extern const struct _mp_obj_module_t os_module;
 extern const struct _mp_obj_module_t pyb_module;
+extern const struct _mp_obj_module_t stm_module;
 extern const struct _mp_obj_module_t time_module;
 #define MICROPY_EXTRA_BUILTIN_MODULES \
     { MP_OBJ_NEW_QSTR(MP_QSTR_os), (mp_obj_t)&os_module }, \
     { MP_OBJ_NEW_QSTR(MP_QSTR_pyb), (mp_obj_t)&pyb_module }, \
+    { MP_OBJ_NEW_QSTR(MP_QSTR_stm), (mp_obj_t)&stm_module }, \
     { MP_OBJ_NEW_QSTR(MP_QSTR_time), (mp_obj_t)&time_module }, \
 
+// extra constants
+#define MICROPY_EXTRA_CONSTANTS \
+    { MP_OBJ_NEW_QSTR(MP_QSTR_pyb), (mp_obj_t)&pyb_module }, \
+    { MP_OBJ_NEW_QSTR(MP_QSTR_stm), (mp_obj_t)&stm_module }, \
+
 // type definitions for the specific machine
 
 #define BYTES_PER_WORD (4)
diff --git a/stmhal/qstrdefsport.h b/stmhal/qstrdefsport.h
index 4eb6ea12a0a29d2f8d464c8f612ca79728db592f..546b5b1430fe3d9ab3809b60584956d07ac9eb20 100644
--- a/stmhal/qstrdefsport.h
+++ b/stmhal/qstrdefsport.h
@@ -130,3 +130,19 @@ Q(sleep)
 
 // for input
 Q(input)
+
+// for stm module
+Q(stm)
+Q(read8)
+Q(read16)
+Q(read32)
+Q(write8)
+Q(write16)
+Q(write32)
+Q(GPIOA)
+Q(GPIOB)
+Q(GPIOC)
+Q(GPIOD)
+Q(GPIO_IDR)
+Q(GPIO_BSRRL)
+Q(GPIO_BSRRH)