diff --git a/rf/nrf24L01/index.html b/rf/nrf24L01/index.html
index 14dbd325a787e8f0e294b864b328ab6c544ee5e6..56959452bfb48c64ea42caba83e59c4da1886c13 100644
--- a/rf/nrf24L01/index.html
+++ b/rf/nrf24L01/index.html
@@ -23,7 +23,17 @@ figure{
 <figcaption>RF Ring oscillator with NRF24L01.  Note: the cursors are measuring half a cycle.</figcaption>
 </figure>
 
-<p>This RF ring oscillator runs on the NRF24L01 using an Xmega 8E5 microcontroller running at 32 MHz.  C code is available in the linked files (<a href='nrf-ftdi-ring.c'>nrf-ftdi-ring.c</a>, <a href='nrf-ftdi-ring.make'>nrf-ftdi-ring.make</a>, <a href='serial.h'>serial.h</a>), or visible below.</p>
+<p>This RF ring oscillator runs on the NRF24L01 using an Xmega 8E5 microcontroller running at 32 MHz.  In the oscilloscope trace above, yellow and blue traces each represent a module.  A pin is pulled high when the radio is active and low while the radio is switching modes.  By measuring two periods of this waveform, we can determine the round trip time (two transmits and two receives).  </p>
+
+<figure>
+<img src='nrf-ftdi-layout.png' height=40%>
+<img src='pcb.jpg' height=40%>
+<figcaption>Layout and PCB.</figcaption>
+</figure>
+
+
+
+<p>C code is available in the linked files (<a href='nrf-ftdi-ring.c'>nrf-ftdi-ring.c</a>, <a href='nrf-ftdi-ring.make'>nrf-ftdi-ring.make</a>, <a href='serial.h'>serial.h</a>), or visible below.</p>
 
 <pre>
 <code>
diff --git a/rf/nrf24L01/pcb.jpg b/rf/nrf24L01/pcb.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..9590a714936002c910ce3f74ea088652b51abda8
Binary files /dev/null and b/rf/nrf24L01/pcb.jpg differ
diff --git a/rf/nrf52832/index.html b/rf/nrf52832/index.html
index b67c2f9c8a44b13b13ac23c3e1a8db957f01dbbd..d498742afd1726e580bb1a1a2532d90dde676fd9 100644
--- a/rf/nrf52832/index.html
+++ b/rf/nrf52832/index.html
@@ -23,7 +23,7 @@ figure{
 <figcaption>RF Ring oscillator with nrf52.</figcaption>
 </figure>
 
-<p>This RF ring oscillator runs on the NRF52 BLE SOC using the Adafruit feather development board.  The NRF52 has an ARM Cortex M4F running at 64 MHz with built in BLE radio.  An arduino sketch for the oscillator is available <a href='nrf52-rf-ring.ino'>here</a>, or visible below.</p>
+<p>This RF ring oscillator runs on the NRF52 BLE SOC using the Adafruit feather development board.  The NRF52 has an ARM Cortex M4F running at 64 MHz with built in BLE radio.  In the oscilloscope trace above, yellow and blue traces each represent a module.  A pin is pulled high when the radio is transmitting and pulled low when the radio is receiving.  By measuring the period, we can determine the time for a packet round trip (two transmits, two recieves).  An arduino sketch for the oscillator is available <a href='nrf52-rf-ring.ino'>here</a>, or visible below.</p>
 
 <pre>
 <code>