diff --git a/firmware/Application/ButtonManager.cpp b/firmware/Application/ButtonManager.cpp
index d0866c3..7377b87 100644
--- a/firmware/Application/ButtonManager.cpp
+++ b/firmware/Application/ButtonManager.cpp
@@ -161,7 +161,7 @@ void ButtonManager::irq()
     static BSP::time_t systime;
 
     // TODO: is this call too expensive for an interrupt handler?
-    //BSP::SystemTimer::get_time(systime);
+    BSP::SystemTimer::get_time(systime);
 
     if (!m_instance) {
         return;
diff --git a/firmware/Bsp/Drivers/LowPower.cpp b/firmware/Bsp/Drivers/LowPower.cpp
index 45622c1..f13e20e 100644
--- a/firmware/Bsp/Drivers/LowPower.cpp
+++ b/firmware/Bsp/Drivers/LowPower.cpp
@@ -50,12 +50,13 @@ ReturnCode LowPower::init(GpioPin &timing_pin)
 ReturnCode LowPower::enable_debug()
 {
     /* Enable Clocks */
+    // FIXME for all boards
     // SET(RCC->APB2ENR, RCC_APB2ENR_DBGEN);
     // SET(RCC->APB2SMENR, RCC_APB2SMENR_DBGSMEN);
 
-    // SET(DBGMCU->CR, DBGMCU_CR_DBG_STOP);
-    // SET(DBGMCU->CR, DBGMCU_CR_DBG_SLEEP);
-    // SET(DBGMCU->CR, DBGMCU_CR_DBG_STANDBY);
+    SET(DBGMCU->CR, DBGMCU_CR_DBG_STOP);
+    SET(DBGMCU->CR, DBGMCU_CR_DBG_SLEEP);
+    SET(DBGMCU->CR, DBGMCU_CR_DBG_STANDBY);
 
     return ReturnCode::OK;
 }
diff --git a/firmware/Test/Apps/button_lowpower.cpp b/firmware/Test/Apps/button_lowpower.cpp
new file mode 100644
index 0000000..339da1e
--- /dev/null
+++ b/firmware/Test/Apps/button_lowpower.cpp
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2020  Max Regan
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "Bsp/Drivers/GpioDriver.h"
+
+#include "Application/ButtonManager.h"
+
+#include "TestBoard.h"
+
+#include "printf.h"
+#include "test.h"
+
+using namespace BSP;
+
+using Button = ButtonManager::Button;
+using ButtonState = ButtonManager::ButtonState;
+
+static GpioPin g_btn_down(g_gpioa, 0);
+static GpioPin g_btn_mid(g_gpioa, 1);
+static GpioPin g_btn_up(g_gpioa, 2);
+
+static ButtonManager g_btn_mgr(g_sched,
+                               g_btn_down,
+                               g_btn_mid,
+                               g_btn_up,
+                               Time::millis(50));
+
+[[noreturn]] void main() {
+
+    board_init();
+    g_debug0_pin.configure_output(GpioDriver::output_mode_t::PUSH_PULL, GpioDriver::output_speed_t::LOW);
+    BSP::LowPower::init(g_debug0_pin);
+
+    g_test_uart.tx_blocking(test_start_text);
+
+    g_btn_down.configure_input(GpioDriver::input_pull_t::PULL_UP);
+    g_btn_mid.configure_input(GpioDriver::input_pull_t::PULL_UP);
+    g_btn_up.configure_input(GpioDriver::input_pull_t::PULL_UP);
+
+    g_btn_mgr.init();
+
+    ButtonManager::ChangeCallback callback =
+        [&](ButtonState state) {
+            g_test_uart.tx_blocking("up:");
+            if (state == ButtonState::PRESSED) {
+                g_test_uart.tx_blocking("pressed\r\n");
+            } else {
+                g_test_uart.tx_blocking("released\r\n");
+            }
+        };
+
+    g_btn_mgr.set_callback(Button::UP, callback);
+
+    Schedule::NextTime asap = Schedule::NextTime::asap();
+    g_sched.add_task(g_test_uart, asap);
+    g_sched.add_task(g_btn_mgr, asap);
+
+    g_test_uart.tx_blocking("Waiting for button press...\r\n");
+    g_sched.run();
+
+    TEST_SPIN();
+}
diff --git a/test/src/tr_test/test.py b/test/src/tr_test/test.py
index 26108c7..f4599dc 100755
--- a/test/src/tr_test/test.py
+++ b/test/src/tr_test/test.py
@@ -244,6 +244,24 @@ def test_button_fast(context_factory, logger):
     assert serial_dev.readline() == b""
 
 
+def test_button_lowpower(context_factory, logger):
+    serial_dev, jlink = context_factory("Test/Apps/button_lowpower.bin")
+    serial_dev.timeout = 0.3
+    ASSERTED = True
+
+    serial_dev.dtr = not ASSERTED
+    while (line := serial_dev.readline()) is not None and len(line) > 0:
+        pass
+
+    for _ in range(5):
+        serial_dev.dtr = ASSERTED
+        press_line = serial_dev.readline()
+        serial_dev.dtr = not ASSERTED
+        release_line = serial_dev.readline()
+        assert press_line == b"up:pressed\r\n"
+        assert release_line == b"up:released\r\n"
+
+
 def test_clock(context_factory, logger):
     serial_dev, jlink = context_factory("Test/Apps/clock.bin")
     EXPECTED_RUNTIME = 10
@@ -325,7 +343,7 @@ def test_lptim(context_factory, logger):
 def test_app_lowpower(context_factory, logger):
     serial_dev, jlink = context_factory("Application/main.bin", leave_halted=True)
     jlink.reset(halt=False)
-    state0_periods, state1_periods = measure_frequency(10, "D1")
+    state0_periods, state1_periods = measure_frequency(10, "D0")
     num_periods = min(len(state0_periods), len(state1_periods))
     periods = [state0_periods[i] + state1_periods[i] for i in range(num_periods)]
     freqs = list(map(lambda x: 1 / x, periods))