diff --git a/include/esp32-lora.h b/include/esp32-lora.h
index 59a9d42..13260ab 100644
--- a/include/esp32-lora.h
+++ b/include/esp32-lora.h
@@ -86,6 +86,7 @@ const long long frequencies[3];
 const long bandwidths[9];
 
 typedef void (*receiveCallback)(uint8_t size);
+typedef void (*txdoneCallback)();
 
 typedef struct {
   EventGroupHandle_t events;
@@ -108,6 +109,7 @@ typedef struct lora32_cfg_t {
   bool implicitHeader;
 
   receiveCallback receive;
+  txdoneCallback tx_done;
   spi_device_handle_t spi;
 
   lora32_handle_t handle;
diff --git a/main/esp32-lora.c b/main/esp32-lora.c
index 9f55836..ff50796 100644
--- a/main/esp32-lora.c
+++ b/main/esp32-lora.c
@@ -133,6 +133,8 @@ void lora32_enable_tx(lora32_cfg_t *lora) {
 }
 
 void lora32_send(lora32_cfg_t *lora, uint8_t *data, uint8_t len) {
+  lora32_write_reg(lora, REG_DIO_MAPPING_1, DIO0_MODE_TXDONE);
+
   lora32_enable_tx(lora);
 
   uint8_t i = 0;
@@ -143,18 +145,7 @@ void lora32_send(lora32_cfg_t *lora, uint8_t *data, uint8_t len) {
 
   lora32_write_reg(lora, REG_OP_MODE, MODE_LONG_RANGE_MODE | MODE_TX);
 
-  lora32_write_reg(lora, REG_DIO_MAPPING_1, DIO0_MODE_TXDONE);
-
   ESP_LOGD(TAG, "lora32_send waiting for TX to finish");
-
-  // can be made async by waiting for DIO0 and checking for IRQ_TX_DONE_MASK
-  while((lora32_read_reg(lora, REG_IRQ_FLAGS) & IRQ_TX_DONE_MASK) == 0) {
-    vTaskDelay(1 / portTICK_PERIOD_MS);
-  }
-
-  ESP_LOGD(TAG, "lora32_send TX done");
-
-  lora32_write_reg(lora, REG_IRQ_FLAGS, IRQ_TX_DONE_MASK);
 }
 
 void lora32_set_frequency(lora32_cfg_t *lora, long frequency) {
@@ -294,9 +285,14 @@ static void IRAM_ATTR lora32_dio0_task(void *arg) {
     lora32_write_reg(lora, REG_IRQ_FLAGS, irqs);
 
     // is this the right check? seems to work but looks off
-    if((irqs & IRQ_RX_DONE_MASK) == IRQ_RX_DONE_MASK) {
+    // TODO handle header validation
+    if((irqs & IRQ_RX_DONE) == IRQ_RX_DONE) {
       lora32_handle_receive(lora);
     }
+
+    if((irqs & IRQ_TX_DONE) == IRQ_TX_DONE) {
+      if(lora->tx_done != NULL) lora->tx_done();
+    }
   }
 }