Telephone Call Logger
Records the start and stop time of ALL outgoing calls along with the number dialled (plus any other digits pressed during the call). It operates "stand alone" - no need for any connection to a PC. Featured in December 2001 issue of Silicon Chip.

Data is stored in non-volatile EEprom memory (24C128) so there is no loss of data during power failures. The kit is supplied with 16K of memory and is expandable in 16K blocks up to 64K total. The logger "auto detects" the amount of available memory - just plug it in and go.

With 64K of memory installed, the logger can record over 2800 10-digit telephone numbers that's 28,000+ digits. With the standard 16K of memory, the logger will record about 2 months worth of calls for the average household.

Logged data can be downloaded into a PC via a serial port and saved to disk. The data is formatted so that it can be easily imported into Microsoft Excel ©. As a bonus, call data is also output in "real time" to the serial port as well as being recorder in memory. This is useful when immediate call analysis and/or external data logging is required.

Here is a sample printout of the logged call data, showing the START and STOP date/time, followed by the number dialled.

27-Aug-01 15:14:08,27-Aug-01 15:40:07,86254690
27-Aug-01 20:39:34,27-Aug-01 21:04:27,96830890
27-Aug-01 21:16:43,27-Aug-01 21:19:52,
28-Aug-01 08:46:36,28-Aug-01 09:04:28,96830890
28-Aug-01 10:43:40,28-Aug-01 10:59:21,96830890

The third line appears to have missed the number dialled. In fact this was an INCOMING call. The logger does not have "caller ID" circuitry and is unable to record the phone number of incoming calls.

Access to the data logger's internal functions, including data downloading, is PASSWORD protected.

The kit is supplied in a plastic case measuring 130(W) x 100(D) x 30(H)mm with silk-screened front and rear panels. The kit is powered by a 9-to-12V DC power supply. A 12VDC 450mA wall adaptor is available.

Two RJ12 (USA type) are provided on the rear panel, marked "LINE" and "PHONE". This allows a telephone to be connected and used even when the logger is put in its place.

Note: Telephone line cords and power supply are NOT supplied with the kit.

Download datasheet file