diff -urp a/master/fsm_foe.c b/master/fsm_foe.c
--- a/master/fsm_foe.c	2013-08-15 18:11:52.000000000 +1200
+++ b/master/fsm_foe.c	2013-08-18 20:44:14.000000000 +1200
@@ -261,6 +261,9 @@ int ec_foe_prepare_data_send(
 
     EC_WRITE_U16(data, EC_FOE_OPCODE_DATA);    // OpCode = DataBlock req.
     EC_WRITE_U32(data + 2, fsm->tx_packet_no); // PacketNo, Password
+#ifdef DEBUG_FOE
+    EC_SLAVE_DBG(fsm->slave, 0, "sending opcode %u packet %u\n", EC_FOE_OPCODE_DATA, fsm->tx_packet_no);
+#endif
 
     memcpy(data + EC_FOE_HEADER_SIZE,
             fsm->tx_buffer + fsm->tx_buffer_offset, current_size);
@@ -298,6 +301,9 @@ int ec_foe_prepare_wrq_send(
 
     EC_WRITE_U16( data, EC_FOE_OPCODE_WRQ); // fsm write request
     EC_WRITE_U32( data + 2, fsm->tx_packet_no );
+#ifdef DEBUG_FOE
+    EC_SLAVE_DBG(fsm->slave, 0, "sending opcode %u packet %u\n", EC_FOE_OPCODE_WRQ, fsm->tx_packet_no);
+#endif
 
     memcpy(data + EC_FOE_HEADER_SIZE, fsm->tx_filename, current_size);
 
@@ -436,6 +442,9 @@ void ec_fsm_foe_state_ack_read(
     }
 
     opCode = EC_READ_U8(data);
+#ifdef DEBUG_FOE
+    EC_SLAVE_DBG(fsm->slave, 0, "received opcode %u\n", opCode);
+#endif
 
     if (opCode == EC_FOE_OPCODE_BUSY) {
         // slave not ready
@@ -571,6 +580,9 @@ int ec_foe_prepare_rrq_send(
     EC_WRITE_U16(data, EC_FOE_OPCODE_RRQ); // fsm read request
     EC_WRITE_U32(data + 2, 0x00000000); // no passwd
     memcpy(data + EC_FOE_HEADER_SIZE, fsm->rx_filename, current_size);
+#ifdef DEBUG_FOE
+    EC_SLAVE_DBG(fsm->slave, 0, "sending opcode %u\n", EC_FOE_OPCODE_RRQ);
+#endif
 
     if (fsm->slave->master->debug_level) {
         EC_SLAVE_DBG(fsm->slave, 1, "FoE Read Request:\n");
@@ -601,6 +613,9 @@ int ec_foe_prepare_send_ack(
 
     EC_WRITE_U16(data, EC_FOE_OPCODE_ACK);
     EC_WRITE_U32(data + 2, fsm->rx_expected_packet_no);
+#ifdef DEBUG_FOE
+    EC_SLAVE_DBG(fsm->slave, 0, "sending opcode %u packet %u\n", EC_FOE_OPCODE_ACK, fsm->rx_expected_packet_no);
+#endif
 
     return 0;
 }
@@ -775,6 +790,9 @@ void ec_fsm_foe_state_data_read(
     }
 
     opCode = EC_READ_U8(data);
+#ifdef DEBUG_FOE
+    EC_SLAVE_DBG(fsm->slave, 0, "received opcode %u\n", opCode);
+#endif
 
     if (opCode == EC_FOE_OPCODE_BUSY) {
         if (ec_foe_prepare_send_ack(fsm, datagram)) {