diff --git a/tools_python/tx.py b/tools_python/tx.py
index 39f4265..7038f1f 100644
--- a/tools_python/tx.py
+++ b/tools_python/tx.py
@@ -4,31 +4,44 @@
 
 import serial
 
-def search_esl_blaster():
-    found = 0
-    for n in range(1, 20):
-        comport = "COM" + str(n)
-        try:
-            ser = serial.Serial(comport, 57600, timeout = 1)    # 1s timeout for read
-            ser.write("?".encode())
-            ser.flush()
-            test = ser.read_until("ESLBlaster")
-            ser.close()
-            if (len(test) >= 10):
-                print("Found ESL Blaster on " + comport)
-                found = 1
-                break
-            else:
-            	print("Timeout on " + comport)
-        except serial.SerialException:
-            #print("SerialException on " + comport)	# Debug
-            continue
+def try_serialport(comport):
+    try:
+        ser = serial.Serial(comport, 57600, timeout = 1)    # 1s timeout for read
+        ser.write("?".encode())
+        ser.flush()
+        test = ser.read_until("ESLBlaster")
+        ser.close()
+        if (len(test) >= 10):
+            print("Found ESL Blaster on " + comport)
+            return True
+        else:
+           	print("Timeout on " + comport)
+           	return False
+    except serial.SerialException:
+        #print("SerialException on " + comport)	# Debug
+        return False
 
-    if (found == 0):
-        print("Could not find ESL Blaster.")
-        return "0"
-    else:
-        return comport
+def search_esl_blaster():
+	found = False
+
+	for n in range(1, 10):
+		comport = "COM" + str(n)
+		if try_serialport(comport):
+			found = True
+			break
+
+	if found == False:
+		for n in range(1, 10):
+			comport = "/dev/ttyACM" + str(n)
+			if try_serialport(comport):
+				found = True
+				break
+
+	if found == False:
+		print("Could not find ESL Blaster.")
+		return "0"
+	else:
+		return comport
 
 def transmit_serial(frames, port):
     ser = serial.Serial(port, 57600, timeout = 10)    # 10s timeout for read
@@ -38,10 +51,10 @@ def transmit_serial(frames, port):
     for fr in frames:
         data_size = len(fr) - 2
         repeats = fr[-2] + (fr[-1] * 256)
-        if repeats > 255:
+        if repeats > 255:	# Cap to one byte for the simple serial transmitter
             repeats = 255
         print("Transmitting frame %u/%u, length %u, repeated %u times." % (i, frame_count, data_size, repeats))
-    
+
         ba = bytearray()
         ba.append(data_size)
         ba.append(repeats)
@@ -70,14 +83,14 @@ def transmit_esl_blaster(frames, port):
         print("Transmitting frame %u/%u, length %u, repeated %u times." % (i, frame_count, data_size, repeats))
 
         ba = bytearray()
-        ba.append(76)	# 'L'
+        ba.append(76)	# L:Load
         ba.append(data_size)
         ba.append(30)   # 30*50 = 1500 timer ticks between repeats
         ba.append(repeats & 255)
         ba.append((repeats // 256) & 255)
-        for b in range(0, len(fr) - 2):
+        for b in range(0, data_size):
             ba.append(fr[b])
-        ba.append(84)	# 'T'
+        ba.append(84)	# T:Transmit
 
         # DEBUG
         #for b in ba:
@@ -86,7 +99,7 @@ def transmit_esl_blaster(frames, port):
 
         ser.write(ba)
         ser.flush()
-        ser.read_until(b'K')
+        ser.read_until(b'K')	# Wait for transmit done
         i += 1
 
     ser.close()