ACR – Auto Call Recorder


Auto Call Recorder (ACR for short) is a freeware application for Windows Mobile 6 Pocket PC devices that can record phone calls automatically. It automatically detects when you are on an incoming or outgoing call and then records the conversation to the folder you specify. It saves the call as a WAV file in the format of [Direction] [FileAs] [Phone Number] [Call Length].


Once installed go to your programs folder and you will see a new Icon for Auto Call Recorder. Click on the Icon and the options for Auto Call Recorder will be displayed. Once you have chosen your options click the Enable Recording button on the File Tab and close the Options Program. That’s it you are now automatically recording any calls your device has.


There are two tabs of options to choose from. Most of these you will not need to use at all but where included to provide a better experience for some users who have different requirements such as limited memory, no use to record all calls and such.

File Tab

Folder to save calls in
From the top of the file tab, first we have a textbox showing where the files will be saved. On the right of this textbox is a button. This button when pressed will open a window so that you may change where ACR saves the files.

Ask to save Call

This checkbox when checked will make ACR prompt you with a choice to save the call once the call has finished. Note that even if you choose no you will still have the option to retrieve the last call up until you receive another call. The file Lastcall.wav is only overwritten when you receive another call.

Record Incoming Calls/Record Outgoing Calls

These checkboxes is pretty self explanatory, if you want ACR to record your incoming calls then check this box, if you don’t then uncheck this box. The same goes for Record Outgoing Calls.

Write to Debug File

Only use this option if you are having problems. At the moment the debug is very limited. When you have this option check ACR will write debug messages to a file ‘debug.txt’ in the installation folder.

Recording Tab

The recording tab contains the setting for the file to be recorded. First is the Wav format. This is either PCM or GSM6.10 PCM is a ‘raw’ wav format that will use about 1MB per minute. I have included this format for devices that do not support GSM6.10. The other format GSM6.10 is a ‘compressed’ Wav format and consumes approximately 30kB per minute. Obviously this is the preferred choice.

Bits per channel are either 8 or 16 bits. 16 bits is the preferred choice but I have also included 8 bits for slower devices.

Samples per Second are the number of samples taken each second. This is a matter of preference/device capability. The choices are 8000, 11025, 16000, 22050, 32000, 44100, 48000, 96000 and 192000Hz. If you have a slow device then you are better starting from the bottom and working your way up by testing to see which the best is for you. If you have a newer device then it is more a choice of how much space you want to use as the higher the number the more space the file will use. Also your device may not support the higher frequencies so I recommend starting with something like 48000Hz. If you set the frequency to high you will get gaps in your recordings.


This program will work on a number of devices at different degrees of success. Below is a few lists of devices and there reported success. If your device is not listed then try it anyway and don’t forget to report back you amount of success. If your device don’t match up to whats reported then please do

Devices known to work ‘Out of the box’ both ways

ASUS P835 (Stock ROM)
Touch HD (Stock ROM 6.1/WM6.5)
HTC Touch Diamond 2 (Stock ROM)
HTC FUZE (updated stock ROM)
HTC TYTN 2 (Stock ROM)
HTC Touch Pro 2 (Stock ROM)
Mio A702 - Not bad for 200Mhz
HTC Rhodium (Stock ROM)
HTC Touch 3G
HTC Trinity - P3600 (Stock ROM)
HTC Touch Cruise (Stock ROM)
HTC Prophet (WM 6.1)
HTC Herald - T-Mobile Wing (Stock ROM)
HTC Touch Elf (Stock ROM)
Samsung i780 (WM 6.1)
Samsung Omnia i900
Samsung Omnia 2
Plam Treo Pro (Stock ROM)
HTC Advantage 7501 (WM6)
HP iPAQ 614c

Devices that require registry setting to work both ways

HTC Touch Diamond – deep_purple reported that after installing GSM610 Codec he could use GSM6.10. Thanks mate.
HTC Touch Pro (EnergyROM / TIR 13R Lite ROM / RRE 6.5 Servies 6 v4)
HTC Blue Angel (Cooked ROM)

Devices that only work one way

Xperia X1

Devices that don’t work

HTC Snap
HTC Vogue
HTC TyTN /> HTC Gene
HP iPAQ 614c

Tips and Fixes

This is a condensed form of the previous thread and this thread. I will cover all the fixes found by the great folk at XDA.

Enable MicAGC. Its in Settings/System. Its not required by all devices though.

“I only hear my voice, the other party is very soft?” This is because you device is not setup to record both the incoming and outgoing voices. This can also be because your device is only ‘half-duplex’. To solve this try the suggestions in the Devices Post.

“ACR only records the first minute of the call?” This is because you have ‘fast sleep’ enabled on your device. Try something like Advanced Configuration Tool to disable fast sleep.

“I can’t see if it’s working?” ACR has no interface when it’s running. It was designed like this to keep memory usage to a minimum. If you are having troubles with this then I suggest you use the ‘Ask to save call’ option so you know it’s worked after the call. You can also see it running in a task manager program when you choose to show ‘view processes’.

Credits and Thanks

Mskip for providing his registry settings from the 2 way recording Cab. Without these settings most devices would only be recording one side of the conversation so if you feel like buying him a beer you can here.

A big thanks to Rozenthal for letting me steal his legal stuff from FingerKeyboard.

Change Log

Version 1.2.5
Removed all beta restrictions and released to testers.

Version 1.2.4
Extended Beta period.

Version 1.2.3
Fixed 12/24 hour time issue if the filename.

Version 1.2.2
Changed the file save format to include the date/time.

Version 1.2.1
Added Choose Folder Dialog.
Added code to stop Windows from shutting down the application in the background.
Added option to record Incoming Calls.
Added option to record Outgoing Calls.
Added Debug to File option.
Removed Readme Tab.


Download ACR Version 1.2.5