diff --git a/Readme.md b/Readme.md
index 0e047e6..904d11b 100644
--- a/Readme.md
+++ b/Readme.md
@@ -29,6 +29,14 @@ pump model number ends with 'WW' then you need a 'WorldWide' firmware:
 
     make -f Makefile.uart1_alt2 RADIO_LOCALE=WW
 
+# cc111x UART1_alt2 connected to the Intel Edison UART_1
+
+    P1.4 - CT / SSN -> UART_1_RTS (GP129) (pin 63)
+    P1.5 - RT / SCK -> UART_1_CTS (GP128) (pin 65)
+    P1.6 - TX / MOSI -> UART_1_RX (GP130) (pin 61)
+    P1.7 - RX / MISO -> UART_1_TX (GP131) (pin 46)
+
+
 # UART on the WirelessThings ERF stick
 
 Perform the build. The output file will be stored at output/uart0_alt1_SRF_ERF_US/uart0_alt1_SRF_ERF_US.hex
diff --git a/radio.c b/radio.c
index 963520e..19ed592 100644
--- a/radio.c
+++ b/radio.c
@@ -89,8 +89,12 @@ void rftxrx_isr(void) __interrupt RFTXRX_VECTOR {
     if (packet_count == 0) {
       packet_count = 1;
     }
-    radio_rx_buf[radio_rx_buf_len] = d_byte;
-    radio_rx_buf_len++;
+    if (radio_rx_buf_len < MAX_PACKET_LEN) {
+      radio_rx_buf[radio_rx_buf_len] = d_byte;
+      radio_rx_buf_len++;
+    } else {
+      // Overflow
+    }
     if (d_byte == 0) {
       RFST = RFST_SIDLE;
       while(MARCSTATE!=MARC_STATE_IDLE);