diff --git a/application.c b/application.c
index 17e7489..5f02c62 100644
--- a/application.c
+++ b/application.c
@@ -11,6 +11,7 @@
 #include <string.h> // string utilities
 #include <time.h> // date/time utilities
 #include <ctype.h> // utilities to check chars
+#include <math.h> // rounding utilities
 
 /* STM32 (including CM3) libraries */
 #include <libopencmsis/core_cm3.h> // Cortex M3 utilities
@@ -51,6 +52,10 @@ static volatile bool second_flag = false; /**< flag set when a second passed */
 /** number of seconds since boot */
 static uint32_t boot_time = 0;
 
+#define TARGET_CHANNEL 1 /**< PA1/ADC1_IN1 used to measure target voltage */
+#define SIGNAL_CHANNEL 2 /**< PA2/ADC1_IN2 used to measure signal voltage */
+const uint8_t channels[] = {ADC_CHANNEL17, ADC_CHANNEL(TARGET_CHANNEL), ADC_CHANNEL(SIGNAL_CHANNEL)}; /**< voltages to convert (channel 17 = internal voltage reference) */
+
 size_t putc(char c)
 {
 	size_t length = 0; // number of characters printed
@@ -69,9 +74,29 @@ size_t putc(char c)
 	return length; // return number of characters printed
 }
 
-#define TARGET_CHANNEL 1 /**< PA1/ADC1_IN1 used to measure target voltage */
-#define SIGNAL_CHANNEL 2 /**< PA2/ADC1_IN2 used to measure signal voltage */
-const uint8_t channels[] = {ADC_CHANNEL17, ADC_CHANNEL(TARGET_CHANNEL), ADC_CHANNEL(SIGNAL_CHANNEL)}; /**< voltages to convert (channel 17 = internal voltage reference) */
+/** print voltage with fixed precision
+ *  @param[in] voltage voltage to print
+ *  @param[in] precision number of digits after comma to print
+ *  @note %f is used to force scientific notation
+ */
+static void print_voltage(double voltage, uint8_t precision)
+{
+	uint32_t multiplier = 1;
+	for (uint8_t i = 0; i < precision; i++) {
+		multiplier *= 10;
+	}
+	double to_print = round(voltage * multiplier);
+	printf("%d.", (int32_t)to_print / multiplier);
+	char decimal[32];
+	snprintf(decimal, LENGTH(decimal), "%u", abs(to_print) % multiplier);
+	if (strlen(decimal) > precision) {
+		decimal[precision] = 0;
+	}
+	for (uint8_t i = strlen(decimal); i < precision; i++) {
+		putc('0');
+	}
+	puts(decimal);
+}
 
 /** measure target and signal voltages
  *  @return voltages of channels
@@ -129,8 +154,16 @@ static void command_voltages(void* argument)
 	(void)argument; // we won't use the argument
 	float* voltages = measure_voltages(); // measure voltages
 	puts("voltages:\n");
-	printf("- target: %.02f V\n", (uint32_t)(voltages[1] * 100) / 100.0);
-	printf("- signal: %.02f V\n", (uint32_t)(voltages[2] * 100) / 100.0);
+	puts("- target: ");
+	print_voltage(voltages[1], 2);
+	puts(" V\n");
+	if (voltages[2] >= 3.25) {
+		puts("- signal: >= 3.30 V\n");
+	} else {
+		puts("- signal: ");
+		print_voltage(voltages[2], 2);
+		puts(" V\n");
+	}
 }
 
 /** display available commands