Super CP Brushless Electrical Noise Fix for XP-3A and DP-3A Micro ESC



Big Thanks to T.Hiro for coming up with the original firmware fix for the Super CP.

Super CP is a very light helicopter that is also very economical. The servos are cheap because the controller is on the mainboard. Is a great platform for going brushless. Unfortunately, when you tap into its throttle signal for ESC, that signal has electrical noise that interfere with ESC operation.

There are several ways to fix the electrical noise issue, but the best way is to program the ESC to ignore the noise. That is exactly what T.Hiro did for the OverSkey 10A ESC. However, the OverSky 10A and XP-7A ESC is larger and heavier (1.4g/2.8g w/ and w/o wire and connector). I want to use the micro DP-3A ESC (.7g-1g w/ connector).

This page has a modified version of T.Hiro's program tailored forthe DP-3A or XP-3A micro ESC.

Step by Step Instruction:

1. Download modified firmware below for either the DP or XP 3A ESC:
In the zip file, use the DP-3A.hex for the DP 3A ESC, and XP-3A .hex file for the XP 3A.

Modified BLHeli file

2. Run the BLHeliSetup.exe program.

3. Plug powered up ESC to USB Toothstick programer and into USB port.

4. Press "Connect" on BLHeli-Setup program

5. Select "Flash BLHeli" as shown below.


6. In the Flash screen, pick "Ignore the list, pick a file...", and select the .hex file from above.


Settings to be aware of:

Startup Power- Keep low. My old batteries could not handle even a 1, and ESC shuts down. .5 is enough.

Beep Strength-Keep low. Too high of a beep seem to cause a ringing in the ESC and interfere with operation. 50 is enough.

Be sure to check whether input is Positive or Negative. Positive if ESC signal wire is connected to the gate pin of the FET on the board, and Negative if ESC signal wire is connected to the motor negative wire.

Uncheck "Re-Arming every Start" and "Programming by TX".




More Details than You Care:


Discussion on modifying firmware files using T.Hiro's file as a template:

This is how I modified T.Hiro's file so it works with the 3A speed controller instead of the 7A speed controller. Don't need to know this, but is here for anyone who is interested.

T.Hiro modified the BLHeli.asm file along with 3 include files (Files with the .inc at the end) to compile the new .hex file. His files are here. One of the include file that is of interest is the file. That is the one that is specific to each ESC. I compared T.Hiro's file with the original BLHeli file. The original XP_7A file created by BLHeli is here.

The result of the file comparison is here. When editing, do not add unecessary space after a line. The crossed out area is where T.Hiro took out lines, and underline areas is where he put in new lines. I followed that, and did the same thing to the BLHeli DP-3A file. The results are below.

Modified file

Modified file

Next is to modify the BLHeli.asm file. That turns out to be relatively simple. At about 10% down the document, put in a ";" in front of the "BESC EQU XP_7A_Main" line and delete the ";" in the XP_3A_Main line. This will tell the compiler you are compiling the XP-3A instead of the XP-3A.

;**** **** **** **** ****
; Select the ESC and mode to use (or unselect all for use with external batch compile file)

The other two .inc files ( and and do not need to be modified. The XP and DP evidently use the same F330 family of processor.

Next is to compile the files to get a .hex file. T.Hiro used the Asem-51 compiler. Link His codes are tailored for that compiler, so just do what he did.

There was an Asem-51 online compiler , but this program was too big for it, so need to install the compiler on the computer. Is DOS based, so installation is a little bit unconvensional.

How to install ASEM-51 link . I did the installation manually using the instructions instead of using automatic installation. That way, I know how to uninstall the compiler. Not sure Windows can uninstall a DOS program.

After the compiler is installed, type "cmd" into the Windows Start button. That brings out a DOS window. Change director to where you put all the files. Remember dos command is "E:" to go to another drive. "CD E:\filename\filename\filename" to get to the file.

Once in the folder where all the documents are, type:

"ASEMW.EXE BLHeli.asm THiro THiro.PRM /;C8051F330.INC;"

The last one "" is for the DP-3A ESC, change that to whatever you are compiling. The .hex file will be written to the same directory.







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