diff --git a/application.c b/application.c
index f9dfa52..3087694 100644
--- a/application.c
+++ b/application.c
@@ -89,6 +89,13 @@ size_t putc(char c)
 	return length; // return number of characters printed
 }
 
+// only print when debug is enabled
+#if DEBUG
+#define puts_debug(x) puts(x)
+#else
+#define puts_debug(x) {}
+#endif
+
 /** print float with fixed precision
  *  @param[in] fpu float to print
  *  @param[in] precision number of digits after comma to print
@@ -663,7 +670,7 @@ void main(void)
 #endif
 
 	// setup RTC
-	puts("setup RTC: ");
+	puts_debug("setup RTC: ");
 	rcc_periph_clock_enable(RCC_RTC); // enable clock for RTC peripheral
 	rcc_osc_on(RCC_LSI); // enable LSI clock
 	while (!rcc_is_osc_ready(RCC_LSI)); // wait until clock is ready
@@ -677,10 +684,10 @@ void main(void)
 		pwr_enable_backup_domain_write_protect(); // re-enable protection now that we configured the RTC clock
 	}
 	boot_time = rtc_to_seconds(); // remember the start time
-	puts("OK\n");
+	puts_debug("OK\n");
 
 	// setup wakeup timer for periodic checks
-	puts("setup wakeup: ");
+	puts_debug("setup wakeup: ");
 	// RTC needs to be configured beforehand
 	pwr_disable_backup_domain_write_protect(); // disable backup protection so we can write to the RTC registers
 	rtc_unlock(); // enable writing RTC registers
@@ -689,9 +696,9 @@ void main(void)
 	rtc_enable_wakeup_timer_interrupt(); // enable interrupt
 	rtc_lock(); // disable writing RTC registers
 	// important: do not re-enable backup_domain_write_protect, since this will prevent clearing flags (but RTC registers do not need to be unlocked)
-	puts("OK\n");
+	puts_debug("OK\n");
 
-	puts("setup voltage control: ");
+	puts_debug("setup voltage control: ");
 	rcc_periph_clock_enable(GPIO_RCC(SIGNAL_PD_PIN)); // enable clock for port domain
 	gpio_set(GPIO_PORT(SIGNAL_PD_PIN), GPIO_PIN(SIGNAL_PD_PIN)); // ensure we are not draining it
 	gpio_set_output_options(GPIO_PORT(SIGNAL_PD_PIN), GPIO_OTYPE_OD, GPIO_OSPEED_2MHZ, GPIO_PIN(SIGNAL_PD_PIN)); // set output as open-drain
@@ -712,9 +719,9 @@ void main(void)
 	gpio_set(GPIO_PORT(TARGET_RST_PIN), GPIO_PIN(TARGET_RST_PIN)); // to not pull down (asserting reset)
 	gpio_set_output_options(GPIO_PORT(TARGET_RST_PIN), GPIO_OTYPE_OD, GPIO_OSPEED_2MHZ, GPIO_PIN(TARGET_RST_PIN)); // set output as open-drain
 	gpio_mode_setup(GPIO_PORT(TARGET_RST_PIN), GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO_PIN(TARGET_RST_PIN)); // configure pin as output
-	puts("OK\n");
+	puts_debug("OK\n");
 
-	puts("setup analog multiplexer: ");
+	puts_debug("setup analog multiplexer: ");
 	rcc_periph_clock_enable(GPIO_RCC(MUX_EN_PIN)); // enable clock for port domain
 	gpio_set(GPIO_PORT(MUX_EN_PIN), GPIO_PIN(MUX_EN_PIN)); // ensure multiplexer is disabled
 	gpio_set_output_options(GPIO_PORT(MUX_EN_PIN), GPIO_OTYPE_PP, GPIO_OSPEED_2MHZ, GPIO_PIN(MUX_EN_PIN)); // set output as push-pull to drive correctly
@@ -736,16 +743,16 @@ void main(void)
 	gpio_set_output_options(GPIO_PORT(MUX_S3_PIN), GPIO_OTYPE_PP, GPIO_OSPEED_2MHZ, GPIO_PIN(MUX_S3_PIN)); // set output as push-pull to drive correctly
 	gpio_mode_setup(GPIO_PORT(MUX_S3_PIN), GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO_PIN(MUX_S3_PIN)); // configure pin as output
 	mux_select(-1); // ensure it is disabled
-	puts("OK\n");
+	puts_debug("OK\n");
 
-	puts("setup signal pins: ");
+	puts_debug("setup signal pins: ");
 	for (uint8_t i = 0; i < CHANNEL_NUMBERS; i++) {
 		rcc_periph_clock_enable(port2rcc(channel_ports[i])); // enable clock for port domain
 		gpio_mode_setup(channel_ports[i], GPIO_MODE_INPUT, GPIO_PUPD_NONE, channel_pins[i]); // ensure pin is floating input
 	}
-	puts("OK\n");
+	puts_debug("OK\n");
 
-	puts("setup ADC to measure voltages: ");
+	puts_debug("setup ADC to measure voltages: ");
 	rcc_periph_clock_enable(RCC_ADC1); // enable clock for ADC domain
 	adc_power_off(ADC1); // switch off ADC while configuring it
 	adc_set_right_aligned(ADC1); // ensure it is right aligned to get the actual value in the 16-bit register
@@ -763,7 +770,7 @@ void main(void)
 	rcc_periph_clock_enable(RCC_ADC1_IN(SIGNAL_CHANNEL)); // enable clock for GPIO domain for signal channel
 	gpio_mode_setup(ADC1_IN_PORT(SIGNAL_CHANNEL), GPIO_MODE_ANALOG, GPIO_PUPD_NONE, ADC1_IN_PIN(SIGNAL_CHANNEL)); // set signal channel as analog input for the ADC
 	measure_voltages(); // try to measure voltages
-	puts("OK\n");
+	puts_debug("OK\n");
 
 	// setup terminal
 	terminal_prefix = ""; // set default prefix