README: Expand on --set-device documentation

README

@@ -315,7 +315,7 @@ Options for both config file and command line:
 --sched-start <arg> Set a time of day in HH:MM to start mining (a once off without a stop time)
 --sched-stop <arg>  Set a time of day in HH:MM to stop mining (will quit without a start time)
 --scrypt            Use the scrypt algorithm for mining (non-bitcoin)
---set-device|--set <arg> Set default parameters on devices; eg, NFY:osc6_bits=50
+--set-device|--set <arg> Set default parameters on devices; eg, NFY:osc6_bits=50, bfl:voltage=<value>, compac:clock=<value>
 --setuid <arg>      Username of an unprivileged user to run as
 --sharelog <arg>    Append share log to file
 --shares <arg>      Quit after mining 2^32 * N hashes worth of shares (default: unlimited)

README.ASIC

@@ -28,6 +28,23 @@ Some valid values for clock setting are:
     x0b82 for 300 MHz, x0c82 for 325 MHz, x0d82 for 350 MHz, x0e82 for 375 MHz,
     and x08f2 for 400 MHz
 
+To set different frequency and voltage settings for multiple U3 miners on a
+single BFGMiner process use:
+
+--set antminer@\\.\COM10:voltage=xNNNN
+
+or
+
+--set antminer@/dev/ttyUSB1:voltage=xNNNN
+
+Another option is to program the CP2102 chip so they have unique serial numbers;
+this method would avoid problems with the device showing up on different tty/COM
+locations after reboot/hotplug:
+
+/cp210x-program -w -F eeprom-content.AntU3-custom.hex --set-product-string='Antminer U3' --set-serial-number=myveryown0001
+
+Then you can use --set antminer@myveryown0001:voltage=xNNNN
+
 
 AVALON 1
 --------
@@ -191,6 +208,12 @@ driver. You can set the clock frequency with
 
 The same values for Antminer U3 (above) are valid for the BM1384.
 
+You can also adjust the clock real-time while the stick is hashing using RPC's pgaset:
+
+bfgminer-rpc "pgaset|0,clock,x0982"
+                     |       ^^^^^ hex frequency
+                     ^ device number
+
 
 HEX*FURY
 --------

miner.c

@@ -2670,7 +2670,12 @@ static struct opt_table opt_config_table[] = {
 #endif
 	OPT_WITH_ARG("--set-device|--set",
 			opt_string_elist_add, NULL, &opt_set_device_list,
-			"Set default parameters on devices; eg, NFY:osc6_bits=50"),
+			"Set default parameters on devices; eg"
+			", NFY:osc6_bits=50"
+			", bfl:voltage=<value>"
+			", compac:clock=<value>"
+	),
+
 #if defined(USE_SCRYPT) && defined(USE_OPENCL)
 	OPT_WITH_ARG("--shaders",
 		     set_shaders, NULL, NULL,