Need datalogger cable

[Jim]

I bought a new SHOCK101 data logger that has the Barnstead ERTO brand on it,
came in a Cole-Parmer box, and came with Madgetech software. I don't really
know who manufactured this item, but there seems to be a lot of identically
named loggers available with different brand names printed on them.

I am in need of a serial communications cable for use with this. At $99
selling price, if I can build one, I would certainly prefer to.

The serial cord, as far as I can see from the Madgetech photos and
description, is simply a 9 pin RS232 connector to a 3.5mm stereo headphone
plug. I suspect the it is simply wired to Tx, Rx and Gnd, but don't know
for sure what goes where. I don't have a cord to trace out and copy. The
logger is powered by an internal 9 volt lithium battery.

I did trace out the datalogger's board and found that the phone jack
on-board is wired to the PIC16LF872 processor in this way:

Sleeve to pins 19 and 8 (ground)
Tip to pin 26
middle connector to pin 21

Is this enough information for someone to assist me in building one of
these? Do these pins on this PIC make sense?

This logger is a single PIC processor, 3 ADXL150 accelerometers, 8-24LC256
memory chips, a LT1121-5 regulator, and not much else.

Thanks
Jim

 

[Dennis]

I bought a new SHOCK101 data logger that has the Barnstead ERTO brand on it,
came in a Cole-Parmer box, and came with Madgetech software. I don't really
know who manufactured this item, but there seems to be a lot of identically
named loggers available with different brand names printed on them.

I am in need of a serial communications cable for use with this. At $99
selling price, if I can build one, I would certainly prefer to.

The serial cord, as far as I can see from the Madgetech photos and
description, is simply a 9 pin RS232 connector to a 3.5mm stereo headphone
plug. I suspect the it is simply wired to Tx, Rx and Gnd, but don't know
for sure what goes where. I don't have a cord to trace out and copy. The
logger is powered by an internal 9 volt lithium battery.

I did trace out the datalogger's board and found that the phone jack
on-board is wired to the PIC16LF872 processor in this way:

Sleeve to pins 19 and 8 (ground)
Tip to pin 26
middle connector to pin 21

Is this enough information for someone to assist me in building one of
these? Do these pins on this PIC make sense?

This logger is a single PIC processor, 3 ADXL150 accelerometers, 8-24LC256
memory chips, a LT1121-5 regulator, and not much else.

Thanks
Jim

The '872 doesn't have serial support as one of the I/O blocks so they
are bit banging it is software. Pins 21 and 26 are general I/O pins. Pin
21 is also the interrupt pin so I would guess it is more likely they
would use that one for the receive pin (they could wait for the start
bit transition rather than monitoring it continuously). I would
recommend going to www.microchip.com and getting the data sheet.