diff --git a/micropython/modules/badger2040/badger2040.c b/micropython/modules/badger2040/badger2040.c
index aa81c828..9c1df9e4 100644
--- a/micropython/modules/badger2040/badger2040.c
+++ b/micropython/modules/badger2040/badger2040.c
@@ -35,6 +35,7 @@ MP_DEFINE_CONST_FUN_OBJ_3(Badger2040_command_obj, Badger2040_command);
 MP_DEFINE_CONST_FUN_OBJ_1(Badger2040_pressed_to_wake_obj, Badger2040_pressed_to_wake);
 MP_DEFINE_CONST_FUN_OBJ_1(Badger2040_halt_obj, Badger2040_halt);
 MP_DEFINE_CONST_FUN_OBJ_0(Badger2040_woken_by_button_obj, Badger2040_woken_by_button);
+MP_DEFINE_CONST_FUN_OBJ_1(Badger2040_system_speed_obj, Badger2040_system_speed);
 
 /***** Binding of Methods *****/
 STATIC const mp_rom_map_elem_t Badger2040_locals_dict_table[] = {
@@ -90,6 +91,7 @@ STATIC const mp_rom_map_elem_t badger2040_globals_table[] = {
 
     { MP_ROM_QSTR(MP_QSTR_pressed_to_wake), MP_ROM_PTR(&Badger2040_pressed_to_wake_obj) },
     { MP_ROM_QSTR(MP_QSTR_woken_by_button), MP_ROM_PTR(&Badger2040_woken_by_button_obj) },
+    { MP_ROM_QSTR(MP_QSTR_system_speed), MP_ROM_PTR(&Badger2040_system_speed_obj) },
 
     { MP_ROM_QSTR(MP_QSTR_UPDATE_NORMAL), MP_ROM_INT(0) },
     { MP_ROM_QSTR(MP_QSTR_UPDATE_MEDIUM), MP_ROM_INT(1) },
@@ -97,6 +99,12 @@ STATIC const mp_rom_map_elem_t badger2040_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_UPDATE_TURBO), MP_ROM_INT(3) },
     { MP_ROM_QSTR(MP_QSTR_UPDATE_SUPER_EXTRA_TURBO), MP_ROM_INT(3) }, // ho ho placebo!
 
+    { MP_ROM_QSTR(MP_QSTR_SYSTEM_VERY_SLOW), MP_ROM_INT(0) },
+    { MP_ROM_QSTR(MP_QSTR_SYSTEM_SLOW), MP_ROM_INT(1) },
+    { MP_ROM_QSTR(MP_QSTR_SYSTEM_NORMAL), MP_ROM_INT(2) },
+    { MP_ROM_QSTR(MP_QSTR_SYSTEM_FAST), MP_ROM_INT(3) },
+    { MP_ROM_QSTR(MP_QSTR_SYSTEM_TURBO), MP_ROM_INT(4) },
+
     { MP_ROM_QSTR(MP_QSTR_WIDTH), MP_ROM_INT(296) },
     { MP_ROM_QSTR(MP_QSTR_HEIGHT), MP_ROM_INT(128) },
 
diff --git a/micropython/modules/badger2040/badger2040.cpp b/micropython/modules/badger2040/badger2040.cpp
index d928b193..9616545f 100644
--- a/micropython/modules/badger2040/badger2040.cpp
+++ b/micropython/modules/badger2040/badger2040.cpp
@@ -139,7 +139,7 @@ MICROPY_EVENT_POLL_HOOK
 
     // Ensure blocking for the minimum amount of time
     // in cases where "is_busy" is unreliable.
-    while(self->badger2040->is_busy() || absolute_time_diff_us(t_end, get_absolute_time()) > 0) {
+    while(self->badger2040->is_busy() || absolute_time_diff_us(get_absolute_time(), t_end) > 0) {
 #ifdef MICROPY_EVENT_POLL_HOOK
 MICROPY_EVENT_POLL_HOOK
 #endif
@@ -517,4 +517,75 @@ mp_obj_t Badger2040_measure_glyph(size_t n_args, const mp_obj_t *pos_args, mp_ma
     return mp_obj_new_int(self->badger2040->measure_glyph(c, scale));
 }
 
+#include "hardware/vreg.h"
+#include "hardware/clocks.h"
+#include "hardware/pll.h"
+
+mp_obj_t Badger2040_system_speed(mp_obj_t speed) {
+    uint32_t sys_freq;
+    uint32_t selected_speed = mp_obj_get_int(speed);
+
+    if (gpio_get(pimoroni::Badger2040::VBUS_DETECT) && selected_speed < 2) {
+      // If on USB never go slower than normal speed.
+      selected_speed = 2;
+    }
+
+    switch (selected_speed)
+    {
+    case 4: // TURBO: 250 MHZ, 1.2V
+        vreg_set_voltage(VREG_VOLTAGE_1_20);
+        set_sys_clock_khz(250000, true);
+        return mp_const_none;
+    case 3: // FAST: 133 MHZ
+        vreg_set_voltage(VREG_VOLTAGE_1_10);
+        set_sys_clock_khz(133000, true);
+        return mp_const_none;
+
+    default:
+    case 2: // NORMAL: 48 MHZ
+        vreg_set_voltage(VREG_VOLTAGE_1_10);
+        set_sys_clock_48mhz();
+        return mp_const_none;
+
+    case 1: // SLOW: 12 MHZ, 1.0V
+        sys_freq = 12 * MHZ;
+        break;
+
+    case 0: // VERY_SLOW: 3 MHZ, 1.0V
+        sys_freq = 3 * MHZ;
+        break;
+    }
+
+
+    // Set the configured clock speed, by dividing the USB PLL
+    clock_configure(clk_sys,
+                    CLOCKS_CLK_SYS_CTRL_SRC_VALUE_CLKSRC_CLK_SYS_AUX,
+                    CLOCKS_CLK_SYS_CTRL_AUXSRC_VALUE_CLKSRC_PLL_USB,
+                    48 * MHZ,
+                    sys_freq);
+
+    clock_configure(clk_peri,
+                    0,
+                    CLOCKS_CLK_PERI_CTRL_AUXSRC_VALUE_CLK_SYS,
+                    sys_freq,
+                    sys_freq);
+
+    clock_configure(clk_adc,
+                    0,
+                    CLOCKS_CLK_ADC_CTRL_AUXSRC_VALUE_CLKSRC_PLL_USB,
+                    48 * MHZ,
+                    sys_freq);
+
+    // No longer using the SYS PLL so disable it
+    pll_deinit(pll_sys);
+
+    // Not using USB so stop the clock
+    clock_stop(clk_usb);
+
+    // Drop the core voltage
+    vreg_set_voltage(VREG_VOLTAGE_1_00);
+
+    return mp_const_none;
+}
+
 }
diff --git a/micropython/modules/badger2040/badger2040.h b/micropython/modules/badger2040/badger2040.h
index 0b6fac44..58ebc851 100644
--- a/micropython/modules/badger2040/badger2040.h
+++ b/micropython/modules/badger2040/badger2040.h
@@ -43,3 +43,5 @@ extern mp_obj_t Badger2040_command(mp_obj_t self_in, mp_obj_t reg, mp_obj_t data
 
 extern mp_obj_t Badger2040_pressed_to_wake(mp_obj_t button);
 extern mp_obj_t Badger2040_woken_by_button();
+
+extern mp_obj_t Badger2040_system_speed(mp_obj_t speed);
diff --git a/micropython/modules/badger2040/micropython.cmake b/micropython/modules/badger2040/micropython.cmake
index 4ae063de..770e4660 100644
--- a/micropython/modules/badger2040/micropython.cmake
+++ b/micropython/modules/badger2040/micropython.cmake
@@ -20,4 +20,7 @@ target_compile_definitions(usermod_${MOD_NAME} INTERFACE
     MODULE_BADGER2040_ENABLED=1
 )
 
-target_link_libraries(usermod INTERFACE usermod_${MOD_NAME})
+target_link_libraries(usermod INTERFACE usermod_${MOD_NAME}
+  hardware_vreg
+  hardware_pll
+  hardware_resets)