diff --git a/src/i2c.c b/src/i2c.c
--- a/src/i2c.c
+++ b/src/i2c.c
@@ -36,6 +36,13 @@ void i2c_init(void)
 }
 
 
+void i2c_deinit(void)
+{
+    HAL_I2C_DeInit(&hi2c1);
+    __I2C1_CLK_DISABLE();
+}
+
+
 // Get pointer to I2C port
 I2C_HandleTypeDef* i2c_get(void)
 {
diff --git a/src/main.c b/src/main.c
--- a/src/main.c
+++ b/src/main.c
@@ -38,7 +38,6 @@ int main(void)
     rtc_init();
     gpio_init();
     adc_init();
-    i2c_init();
     wspr_init();
 
     uint32_t led_timer = HAL_GetTick();
@@ -61,7 +60,7 @@ int main(void)
     {
 
     	// Every 10 minutes, wake up and try to wspr
-    	if(HAL_GetTick() - last_wspr_tx_time > 60000 * 10)
+    	if(state == SYSTEM_IDLE && (HAL_GetTick() - last_wspr_tx_time > 60000 * 10))
     	{
     		state = SYSTEM_GPSACQ;
     	}
@@ -150,7 +149,7 @@ int main(void)
             // Wait for wspr timeslot and start transmitting
             case SYSTEM_WSPRTX:
             {
-            	blink_rate = BLINK_SLOW;
+            	blink_rate = BLINK_MED;
                 // Wait for wspr countdown timer to expire and go to tx
 //                if(timeout_expired)
 //                {
@@ -166,8 +165,8 @@ int main(void)
 
             			__calc_gridloc(grid_locator, latitude_flt, longitude_flt);
 
+						last_wspr_tx_time = HAL_GetTick();
 						wspr_transmit(grid_locator);
-						last_wspr_tx_time = HAL_GetTick();
 						state = SYSTEM_IDLE;
             		}
             		else
diff --git a/src/wspr.c b/src/wspr.c
--- a/src/wspr.c
+++ b/src/wspr.c
@@ -30,19 +30,6 @@ TIM_HandleTypeDef htim1;
 
 void wspr_init(void)
 {
-    // Start timer for WSPR
-    __TIM1_CLK_ENABLE();
-    htim1.Instance = TIM1;
-    htim1.Init.Prescaler = 512; // gives 64uS ticks from 8MHz ahbclk
-    htim1.Init.CounterMode = TIM_COUNTERMODE_UP;
-    htim1.Init.Period = ctc; // Count up to this value (how many 64uS ticks per symbol)
-    htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
-    htim1.Init.RepetitionCounter = 0;
-    HAL_TIM_Base_Init(&htim1);
-    HAL_TIM_Base_Start_IT(&htim1);
-    HAL_NVIC_SetPriority(TIM1_BRK_UP_TRG_COM_IRQn, 0, 0);
-    HAL_NVIC_EnableIRQ(TIM1_BRK_UP_TRG_COM_IRQn);
-
     // Turn off ICs
     HAL_GPIO_WritePin(OSC_NOTEN, 1);
     HAL_GPIO_WritePin(TCXO_EN, 0);
@@ -68,11 +55,27 @@ void wspr_transmit(uint8_t* grid_locator
 		loc[i] = grid_locator[i];
 	loc[4] = '\0';
 
+
+    // Start timer for WSPR
+    __TIM1_CLK_ENABLE();
+    htim1.Instance = TIM1;
+    htim1.Init.Prescaler = 512; // gives 64uS ticks from 8MHz ahbclk
+    htim1.Init.CounterMode = TIM_COUNTERMODE_UP;
+    htim1.Init.Period = ctc; // Count up to this value (how many 64uS ticks per symbol)
+    htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
+    htim1.Init.RepetitionCounter = 0;
+    HAL_TIM_Base_Init(&htim1);
+    HAL_TIM_Base_Start_IT(&htim1);
+    HAL_NVIC_SetPriority(TIM1_BRK_UP_TRG_COM_IRQn, 0, 0);
+    HAL_NVIC_EnableIRQ(TIM1_BRK_UP_TRG_COM_IRQn);
+
+
     HAL_GPIO_WritePin(OSC_NOTEN, 0);
     HAL_GPIO_WritePin(TCXO_EN, 1);
     HAL_Delay(100);
 
     // Bring up the chip
+    i2c_init();
     si5351_init(i2c_get(), SI5351_CRYSTAL_LOAD_8PF, 0);
     si5351_set_correction(0);
     //si5351_set_pll(SI5351_PLL_FIXED, SI5351_PLLA);
@@ -114,5 +117,16 @@ void wspr_transmit(uint8_t* grid_locator
 
     HAL_GPIO_WritePin(OSC_NOTEN, 1);
     HAL_GPIO_WritePin(TCXO_EN, 0);
+
+    i2c_deinit();
+
+    // Disable timer
+    HAL_NVIC_DisableIRQ(TIM1_BRK_UP_TRG_COM_IRQn);
+    HAL_TIM_Base_Stop_IT(&htim1);
+    HAL_TIM_Base_DeInit(&htim1);
+
+    __TIM1_CLK_DISABLE();
+
+
 }