diff --git a/librfm.c b/librfm.c
index f4715f9..db96cf5 100644
--- a/librfm.c
+++ b/librfm.c
@@ -62,7 +62,7 @@
 static void timeoutEnable(bool enable) {
     if (enable) {
         // get "Timeout" on DIO4 (default)
-        regWrite(DIO_MAP2, 0x00);
+        regWrite(DIO_MAP2, regRead(DIO_MAP2) & ~0xc0);
         // both sum up to about 100 ms
         regWrite(RX_TO_RSSI, 0x1f);
         regWrite(RX_TO_PRDY, 0x1f);
@@ -214,7 +214,7 @@
 
 void rfmStartReceive(void) {
     // get "PayloadReady" on DIO0
-    regWrite(DIO_MAP1, 0x40);
+    regWrite(DIO_MAP1, (regRead(DIO_MAP1) & ~0x80) | 0x40);
 
     setMode(MODE_RX);
 }
@@ -237,7 +237,7 @@
     size_t len = regRead(FIFO);
     len = min(len, size);
 
-    // TODO assume and ignore address for now
+    // TODO assume and ignore address for now (already filtered anyway)
     regRead(FIFO);
 
     _rfmSel();
@@ -290,10 +290,11 @@
     _rfmDes();
 
     // get "PacketSent" on DIO0 (default)
-    regWrite(DIO_MAP1, 0x00);
+    regWrite(DIO_MAP1, regRead(DIO_MAP1) & ~0xc0);
 
     setMode(MODE_TX);
 
+    // wait until "PacketSent"
     do {} while (!(irqFlags2 & (1 << 3)));
     clearIrqFlags();
 
diff --git a/librfm.h b/librfm.h
index f8d598f..f921684 100644
--- a/librfm.h
+++ b/librfm.h
@@ -69,9 +69,11 @@
 #define MODE_TX     0x0c
 #define MODE_RX     0x10
 
-#define PA_OFF      18
+#define DBM_MIN     -2
+#define DBM_MAX     13
 #define PA_MIN      16
 #define PA_MAX      31
+#define PA_OFF      18
 
 #define MESSAGE_SIZE    63
 #define F_STEP          6103515625ULL