Merge pull request #1029 from pimoroni/feature/scd4x-low-power

SCD4X: API bump and possible low power support

Author: Gadgetoid

drivers/scd4x/src

@@ -13,6 +13,7 @@ static MP_DEFINE_CONST_FUN_OBJ_KW(scd41_init_obj, 0, scd41_init);
 
 // Start/Stop measurement, no args (module-level, so no "self")
 static MP_DEFINE_CONST_FUN_OBJ_0(scd41_start_periodic_measurement_obj, scd41_start_periodic_measurement);
+static MP_DEFINE_CONST_FUN_OBJ_0(scd41_start_low_power_periodic_measurement_obj, scd41_start_low_power_periodic_measurement);
 static MP_DEFINE_CONST_FUN_OBJ_0(scd41_stop_periodic_measurement_obj, scd41_stop_periodic_measurement);
 static MP_DEFINE_CONST_FUN_OBJ_0(scd41_get_data_ready_obj, scd41_get_data_ready);
 
@@ -30,6 +31,7 @@ static const mp_map_elem_t scd41_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_breakout_scd41) },
     { MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&scd41_init_obj) },
     { MP_ROM_QSTR(MP_QSTR_start), MP_ROM_PTR(&scd41_start_periodic_measurement_obj) },
+    { MP_ROM_QSTR(MP_QSTR_start_low_power), MP_ROM_PTR(&scd41_start_low_power_periodic_measurement_obj) },
     { MP_ROM_QSTR(MP_QSTR_stop), MP_ROM_PTR(&scd41_stop_periodic_measurement_obj) },
     { MP_ROM_QSTR(MP_QSTR_measure), MP_ROM_PTR(&scd41_read_measurement_obj) },
     { MP_ROM_QSTR(MP_QSTR_ready), MP_ROM_PTR(&scd41_get_data_ready_obj) },

micropython/modules/breakout_scd41/breakout_scd41.c

@@ -64,20 +64,33 @@ mp_obj_t scd41_start_periodic_measurement() {
     return mp_const_none;
 }
 
+mp_obj_t scd41_start_low_power_periodic_measurement() {
+    if(!scd41_initialised) {
+        mp_raise_msg(&mp_type_RuntimeError, NOT_INITIALISED_MSG);
+        return mp_const_none;
+    }
+    int error = scd4x_start_low_power_periodic_measurement();
+    if(error) {
+        mp_raise_msg(&mp_type_RuntimeError, FAIL_MSG);
+    }
+
+    return mp_const_none;
+}
+
 mp_obj_t scd41_get_data_ready() {
     if(!scd41_initialised) {
         mp_raise_msg(&mp_type_RuntimeError, NOT_INITIALISED_MSG);
         return mp_const_none;
     }
-    uint16_t data_ready = 0;
-    int error = scd4x_get_data_ready_status(&data_ready);
+    bool data_ready = false;
+    int error = scd4x_get_data_ready_flag(&data_ready);
     if(error) {
         mp_raise_msg(&mp_type_RuntimeError, READ_FAIL_MSG);
         return mp_const_none;
     }
     // The datasheet doesn't really say *which* bit might be 1 if data is ready...
     // so check if the least significant eleven bits are != 0
-    return (data_ready & 0x7ff) ? mp_const_true : mp_const_false;
+    return data_ready ? mp_const_true : mp_const_false;
 }
 
 mp_obj_t scd41_set_temperature_offset(mp_obj_t offset) {

micropython/modules/breakout_scd41/breakout_scd41.cpp

@@ -5,6 +5,7 @@
 // Declare the functions we'll make available in Python
 extern mp_obj_t scd41_init(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args);
 extern mp_obj_t scd41_start_periodic_measurement();
+extern mp_obj_t scd41_start_low_power_periodic_measurement();
 extern mp_obj_t scd41_stop_periodic_measurement();
 extern mp_obj_t scd41_read_measurement();
 extern mp_obj_t scd41_get_data_ready();