diff --git a/firmware/isp.c b/firmware/isp.c
index 5e51bf0..9c9b72e 100755
--- a/firmware/isp.c
+++ b/firmware/isp.c
@@ -140,6 +140,15 @@ void ispDisconnect() {
 	spiHWdisable();
 }
 
+void spiInit() {
+	/* Set MISO output, all others input */
+	ISP_DDR = (1 << ISP_MISO);
+	/* Pull up SS' */
+	ISP_OUT = (1 << ISP_RST);
+	/* Enable SPI, slave mode */
+	SPCR = (1 << SPE | 1<< SPIE);
+}
+
 uchar ispTransmit_sw(uchar send_byte) {
 
 	uchar rec_byte = 0;
diff --git a/firmware/isp.h b/firmware/isp.h
index 2300a58..87f1ed5 100755
--- a/firmware/isp.h
+++ b/firmware/isp.h
@@ -30,6 +30,9 @@ void ispConnect();
 /* Close connection to target device */
 void ispDisconnect();
 
+/* Prepare to listen to target device */
+void spiInit();
+
 /* read an write a byte from isp using software (slow) */
 uchar ispTransmit_sw(uchar send_byte);
 
diff --git a/firmware/main.c b/firmware/main.c
index a225432..22c7cea 100755
--- a/firmware/main.c
+++ b/firmware/main.c
@@ -27,6 +27,14 @@
 
 static uchar replyBuffer[8];
 
+// choose size to 2^8, so comStart, comEnd can wrap around as ringbuffer
+// indexes.
+static uchar comBuffer[256];
+static uchar comStart = 0;
+static uchar comStop = 0;
+
+unsigned int blink_counter;
+
 static uchar prog_state = PROG_STATE_IDLE;
 static uchar prog_sck = USBASP_ISP_SCK_AUTO;
 
@@ -37,6 +45,13 @@ static unsigned int prog_pagesize;
 static uchar prog_blockflags;
 static uchar prog_pagecounter;
 
+
+ISR(SPI_STC_vect )
+{
+    comBuffer[comStop] = SPDR;
+    comStop ++;
+}
+
 uchar usbFunctionSetup(uchar data[8]) {
 
 	uchar len = 0;
@@ -190,6 +205,23 @@ uchar usbFunctionSetup(uchar data[8]) {
 		replyBuffer[2] = 0;
 		replyBuffer[3] = 0;
 		len = 4;
+
+	} else if (data[1] == USBASP_FUNC_SPI_RECVSTART) {
+		spiInit();
+		prog_state = PROG_STATE_SERIAL;
+
+	} else if (data[1] == USBASP_FUNC_SPI_RECVSTOP) {
+		ledRedOff();
+		ispDisconnect();
+		prog_state = PROG_STATE_IDLE;
+
+	} else if (data[1] == USBASP_FUNC_SPI_RECV) {
+		len = 0;
+		while (comStart != comStop && len < 8) {
+			replyBuffer[len] = comBuffer[comStart];
+			comStart ++;
+			len ++;
+		}
 	}
 
 	usbMsgPtr = replyBuffer;
@@ -334,6 +366,12 @@ int main(void) {
 	sei();
 	for (;;) {
 		usbPoll();
+		if (prog_state == PROG_STATE_SERIAL) {
+			if (--blink_counter == 0) {
+				toggleLedRed();
+				blink_counter = (unsigned int)(1UL << 15);
+			}
+		}
 	}
 	return 0;
 }
diff --git a/firmware/usbasp.h b/firmware/usbasp.h
index b60bd04..d530dda 100644
--- a/firmware/usbasp.h
+++ b/firmware/usbasp.h
@@ -30,6 +30,10 @@
 #define USBASP_FUNC_TPI_WRITEBLOCK   16
 #define USBASP_FUNC_GETCAPABILITIES 127
 
+#define USBASP_FUNC_SPI_RECVSTART 32
+#define USBASP_FUNC_SPI_RECV 33
+#define USBASP_FUNC_SPI_RECVSTOP 34
+
 /* USBASP capabilities */
 #define USBASP_CAP_0_TPI    0x01
 
@@ -41,6 +45,7 @@
 #define PROG_STATE_WRITEEEPROM  4
 #define PROG_STATE_TPI_READ     5
 #define PROG_STATE_TPI_WRITE    6
+#define PROG_STATE_SERIAL       7
 
 /* Block mode flags */
 #define PROG_BLOCKFLAG_FIRST    1
@@ -67,4 +72,13 @@
 #define ledGreenOn()  PORTC &= ~(1 << PC0)
 #define ledGreenOff() PORTC |= (1 << PC0)
 
+#define isLedRedOff()   (PORTC & (1 << PC1))
+#define isLedRedOn()    ~(isLedRedOff())
+#define isLedGreenOff() (PORTC & (1 << PC0))
+#define isLedGreenOn()  ~(isLedGreenOff())
+
+#define toggleLedRed()  PORTC ^= (1 << PC1)
+#define toggleLedGreen()  PORTC ^= (1 << PC0)
+
+
 #endif /* USBASP_H_ */