diff --git a/Core/Src/MP45DT02.c b/Core/Src/MP45DT02.c
index da4f630..3aacaab 100644
--- a/Core/Src/MP45DT02.c
+++ b/Core/Src/MP45DT02.c
@@ -4,7 +4,10 @@
 
 #define SAMPLE_AMOUNT 256
 
-//extern I2S_HandleTypeDef hi2s2;
+struct TestResult {
+	unsigned int lo_present:1;
+	unsigned int hi_present:1;
+};
 
 int MP45DT02_run_test(void)
 {
@@ -14,66 +17,67 @@ int MP45DT02_run_test(void)
 	uint16_t sample_buffer[SAMPLE_AMOUNT];
 
 	for (size_t t = 0; t < 5; t++) {
-		//HAL_I2S_Receive(&hi2s2, sample_buffer, SAMPLE_AMOUNT, 1000);
+		// gather samples
+		register unsigned int reset_value = (GPIO_PIN_10 << 16);
 
 		for (size_t i = 0; i < SAMPLE_AMOUNT; i++) {
 			sample_buffer[i] = 0;
 			for (size_t j = 0; j < 16; j++) {
-				HAL_GPIO_WritePin(GPIOB, GPIO_PIN_10, GPIO_PIN_SET);
-				asm("nop");
-				asm("nop");
+				for (int k = 0; k < 16; k++) {
+					GPIOB->BSRR = reset_value;
+					asm("nop");
+					asm("nop");
+					asm("nop");
+					asm("nop");
+					asm("nop");
+					asm("nop");
+					asm("nop");
+					asm("nop");
+					asm("nop");
+					asm("nop");
+					asm("nop");
+					GPIOB->BSRR = GPIO_PIN_10;
+				}
 				sample_buffer[i] <<= 1;
-				sample_buffer[i] |= HAL_GPIO_ReadPin(GPIOC, GPIO_PIN_3);
-				HAL_GPIO_WritePin(GPIOB, GPIO_PIN_10, GPIO_PIN_RESET);
-				asm("nop");
-				asm("nop");
-				asm("nop");
-				asm("nop");
-				asm("nop");
-				asm("nop");
-				asm("nop");
-				asm("nop");
-				asm("nop");
-				asm("nop");
-				asm("nop");
-				asm("nop");
+				sample_buffer[i] |= (GPIOC->IDR & (1 << 3)) >> 3;
 			}
 		}
 
+		struct TestResult res = {};
+
+		// look for zeros
 		for (size_t i = 0; i < SAMPLE_AMOUNT / 2; i++)
-			if (((uint32_t *) sample_buffer)[i]) {
-				DISPLAY_CLEAR;
-				display_write_data_seq("MP45DT02 Mic");
-
-				if (!t) {
-					DISPLAY_SET_CURSOR(1, 4);
-					display_write_data_seq("OK");
-				} else {
-					DISPLAY_SET_CURSOR(1, 4);
-					display_write_data_byte('0' + t);
-					display_write_data_seq(" 0 samples");
-				}
-
-				return 0;
+			if (~((uint32_t *) sample_buffer)[i]) {
+				res.lo_present = 1;
+				break;
+			}
+
+		// look for ones
+		for (size_t i = 0; i < SAMPLE_AMOUNT / 2; i++)
+			if (((uint32_t *) sample_buffer)[i]) {
+				res.hi_present = 1;
+				break;
 			}
 
-		// if ended up here, then no samples equaled to 1; that is not a good sign
 		DISPLAY_CLEAR;
 		display_write_data_seq("MP45DT02 Mic");
 
+		if (t) {
+			DISPLAY_SET_CURSOR(1, 14);
+			display_write_data_byte('T');
+			display_write_data_byte('0' + t + 1);
+		}
+
 		DISPLAY_SET_CURSOR(1, 4);
-		display_write_data_byte('1' + t);
-		display_write_data_seq("/5: all zeros");
-
-		HAL_Delay(1000);
+		if (res.lo_present & res.hi_present) {
+			display_write_data_seq("OK");
+			return 0;
+		} else if (res.lo_present) {
+			display_write_data_seq("ALWAYS LO");
+		} else if (res.hi_present) {
+			display_write_data_seq("ALWAYS HI");
+		}
 	}
 
-	// t = 5, not a single 1 was recorded; microphone might be broken
-	DISPLAY_CLEAR;
-	display_write_data_seq("MP45DT02 Mic");
-
-	DISPLAY_SET_CURSOR(1, 4);
-	display_write_data_seq("NO ONES");
-
 	return 1;
 }
diff --git a/Core/Src/main.c b/Core/Src/main.c
index 95ac39c..6612dcd 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -598,11 +598,11 @@ static void MX_GPIO_Init(void)
   GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
   HAL_GPIO_Init(GPIOE, &GPIO_InitStruct);
 
-  /*Configure GPIO pins : PB10 PB7 */
-  GPIO_InitStruct.Pin = GPIO_PIN_10|GPIO_PIN_7;
+  /*Configure GPIO pin : PB10 */
+  GPIO_InitStruct.Pin = GPIO_PIN_10;
   GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
   GPIO_InitStruct.Pull = GPIO_NOPULL;
-  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
+  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
   HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
 
   /*Configure GPIO pin : PD11 */
@@ -621,6 +621,13 @@ static void MX_GPIO_Init(void)
   GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
   HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);
 
+  /*Configure GPIO pin : PB7 */
+  GPIO_InitStruct.Pin = GPIO_PIN_7;
+  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
+  GPIO_InitStruct.Pull = GPIO_NOPULL;
+  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
+  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
+
 /* USER CODE BEGIN MX_GPIO_Init_2 */
 /* USER CODE END MX_GPIO_Init_2 */
 }
diff --git a/test1.ioc b/test1.ioc
index 5b9e6f9..0e5f37f 100644
--- a/test1.ioc
+++ b/test1.ioc
@@ -99,6 +99,8 @@ PA7.Mode=RMII
 PA7.Signal=ETH_CRS_DV
 PB1.Locked=true
 PB1.Signal=ADCx_IN9
+PB10.GPIOParameters=GPIO_Speed
+PB10.GPIO_Speed=GPIO_SPEED_FREQ_HIGH
 PB10.Locked=true
 PB10.Signal=GPIO_Output
 PB11.Mode=RMII