HOBO® 4-Channel External Logger
Brooke Clarke 2000 - 2007
This is a small battery powered data logger with 4 analog inputs
0 to +2.5 volts. It is powered by a CR2032 3 volt Lithium
battery. The "Boxcar" software package is required to "launch"
up the sampling rate, which channels are active, etc.) the Hobo and
read back it's data.
Radio Shack can order as RSU12045522 or get from Onset
Computer Corporation - HOBO®
External Logger -
Also see my Onset G-Pendant web page.
Using Readout on the 4-Channel unit stops the data logging.
are clear that launching the unit will clear the memory, but if
the data stops the logging function that's the same as clearing the
because to get it going again you need to launch it!
The inputs have 2.5mm stereo audio jacks.
2.5mm Plug is Tech
910-0727 in catalog but may not be on their web site
Sleeve is ground (Black wire on "CABLE-2.5-STEREO")
Ring is 2.5 volts out to sensor (Red wire on cable)
Tip is 0 to +2.5V Hobo input (White wire on cable)
Chip Side of Board,
Battery Side of Board
4 ea. 24LC65 8k x 8 bit serial EPROM memory chips (the 24LC64
is listed but not the 24LC65)
The 24LC series are 8-pin, 2 wire I2C interface
5 Volt and up to 8 can be connected to a common buss.
8 to 1 MUX
8 bit A/D I2C converter
Hobo to Computer Cable
The cable that comes with the Boxcar software package
3.5mm stereo audio plug ( Digikey
CP-3502-ND, Tech America
to connect to the Hobo and a DB9(f) that connects to the computer
CUI Stack carries both
and 3.5mm jacks
Sleeve to pin 5 Signal Ground
Ring Hobo Tx data to pin 2 Computer Rx Data
Tip Hobo Rx data from pin 3 Computer Tx Data
TSL250 Light Sensor
By using the following parts I made up a light sensor:
3-lead Light Sensor (Radio Shack RSU 11673308)
4.5 Volt computer back up battery (had one so used it)
CABLE-2.5-STEREO (Radio Shack RSU 11915527)
10 K Ohm & 2.2 K Ohm resistors to divide output down from
sun) to 2.4 volts
Here is a file that was "exported" in Excel format for July (July5.txt)
Also see the G Pendant 3-axis Onset
Back to Brooke's Sensors, Home