diff --git a/firmware/pico_rng.c b/firmware/pico_rng.c
index 8d00884..bf68bd7 100644
--- a/firmware/pico_rng.c
+++ b/firmware/pico_rng.c
@@ -578,10 +578,38 @@ void ep1_out_handler(uint8_t *buf, uint16_t len) {
     usb_start_transfer(ep, (char*)new_buf, size);
 }
 
+void get_random_data(char *buffer, uint16_t len) {
+    uint16_t adc_result;
+    uint8_t size;
+    int i;
+
+    gpio_put(25, 1);
+
+    if(len > 64)
+    {
+        //TODO handle length error
+        size = 64;
+    }
+
+    memset(buffer, 0, len);
+    for(i = 1; i <= len; i=i+1)
+    {
+        adc_result = adc_read();
+        memcpy(&buffer[i-1], (void*)&adc_result, 2);
+    }
+
+    gpio_put(25, 0);
+}
+
 void ep2_in_handler(uint8_t *buf, uint16_t len) {
     printf("Sent %d bytes to host\n", len);
     // Get ready to rx again from host
-    usb_start_transfer(usb_get_endpoint_configuration(EP1_OUT_ADDR), NULL, 64);
+
+    char buffer[64];
+    get_random_data(buffer, 64);
+    //usb_start_transfer(usb_get_endpoint_configuration(EP1_OUT_ADDR), NULL, 64);
+    struct usb_endpoint_configuration *ep = usb_get_endpoint_configuration(EP2_IN_ADDR);
+    usb_start_transfer(ep, buffer, 64);
 }
 
 int main(void) {
@@ -604,8 +632,12 @@ int main(void) {
         tight_loop_contents();
     }
 
-    // Get ready to rx from host
-    usb_start_transfer(usb_get_endpoint_configuration(EP1_OUT_ADDR), NULL, 64);
+    char buffer[64];
+
+    // Get ready to tx
+    get_random_data(buffer, 64);
+    usb_start_transfer(usb_get_endpoint_configuration(EP2_IN_ADDR), buffer, 64);
+    //usb_start_transfer(usb_get_endpoint_configuration(EP1_OUT_ADDR), NULL, 64);
 
     // Everything is interrupt driven so just loop here
     while (1) {
diff --git a/firmware/pico_rng_test.py b/firmware/pico_rng_test.py
index 95d5942..0e17f69 100755
--- a/firmware/pico_rng_test.py
+++ b/firmware/pico_rng_test.py
@@ -1,50 +1,44 @@
 #!/usr/bin/env python3
 
-#
-# Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
-#
-# SPDX-License-Identifier: BSD-3-Clause
-#
-
-# sudo pip3 install pyusb
-
 import usb.core
 import usb.util
 import random
+import time
+import argparse
 
-# find our device
-dev = usb.core.find(idVendor=0x0000, idProduct=0x0004)
+# Parser stuff
+parser = argparse.ArgumentParser(description="Raspberry Pi Pico Random Number Generator Test Tool")
+parser.add_argument("--performance", action="store_true", help="Performance test the RNG.")
+args = parser.parse_args()
 
-# was it found?
-if dev is None:
-    raise ValueError('Device not found')
+# Get the device
+rng = usb.core.find(idVendor=0x0000, idProduct=0x0004)
+assert rng is not None
 
-# get an endpoint instance
-cfg = dev.get_active_configuration()
-intf = cfg[(0, 0)]
+# Get the configuration of the device
+cfg = rng.get_active_configuration()
 
-outep = usb.util.find_descriptor(
-    intf,
-    # match the first OUT endpoint
-    custom_match= \
-        lambda e: \
-            usb.util.endpoint_direction(e.bEndpointAddress) == \
-            usb.util.ENDPOINT_OUT)
+# Get the only interface of our device
+intf = cfg.interfaces()[0]
 
-inep = usb.util.find_descriptor(
-    intf,
-    # match the first IN endpoint
-    custom_match= \
-        lambda e: \
-            usb.util.endpoint_direction(e.bEndpointAddress) == \
-            usb.util.ENDPOINT_IN)
+# Get the endpoints
+endpts = intf.endpoints()
 
-assert inep is not None
-assert outep is not None
+# Get the IN or Host RCV Device TX endpoint
+endpts_in = endpts[0] if endpts[0].bEndpointAddress == usb.util.ENDPOINT_IN else endpts[1]
 
-num_bytes = random.randint(1,64)
+# Time tracking for bits/s
+count = 0
+start_time = (int(time.time()) - 1)
 
-outep.write([num_bytes], 500)
-from_device = inep.read(num_bytes, 500)
-
-print(":".join("{:02x}".format(b) for b in from_device))
+if args.performance:
+    while True:
+        try:
+            from_device = endpts_in.read(endpts_in.wMaxPacketSize, 500)
+            count = count+1
+            print(":".join("{:02x}".format(b) for b in from_device), end="")
+            print(" KBps {0:.2f}".format((int((count * 64) / (int(time.time()) - start_time))) / 1024 ))
+        except KeyboardInterrupt:
+            exit(0)
+else:
+    print(":".join("{:02x}".format(b) for b in endpts_in.read(endpts_in.wMaxPacketSize, 500)))