JERICHO TDL-RevB User manual

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USER GUIDE–
THERMISTOR DATA LOGGER (TDL) REV.B
V1.1 - JERICHO LABORATORY INC. - JERICHOLAB.COM
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Table of Contents
OVERVIEW............................................................................................................................................................4
REQUIREMENTS...................................................................................................................................................4
SERIAL COMMANDS ............................................................................................................................................5
QUICK START........................................................................................................................................................7
HOW TO UPLOAD THE SOURCE CODE TO THE TDL.........................................................................................10
ADDITIONAL DOCUMENTATION AND FILES ....................................................................................................11
PRODUCT SPECIFICATIONS ...............................................................................................................................13
REFERENCES.......................................................................................................................................................14
CONTACT............................................................................................................................................................14
WARRANTY ........................................................................................................................................................14
ABOUT JERICHO LAB..........................................................................................................................................14
ABOUT ARDUINO...............................................................................................................................................15
FREQUENTLY ASKED QUESTIONS (FAQ)...........................................................................................................15

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OVERVIEW
WARNING: This product contains small parts. Not for children under 5 years old.
WARNING: This product is not intended for critical use, internal use or medical use.
DISCLAIMER: Jericho Laboratory will not be held responsible for any damage other than to the device
itself.
The Thermistor Data Logger (TDL) can measure 1 to 8 temperatures simultaneously. It is compatible
with the Arduino Nano 3.0 ©. Data is sent continuously to the computer.
PRODUCT FEATURES
Designed for scientists, engineers and researchers
Ready-to-use product
Can measure temperatures, relative humidity, radiant temperature, luminosity, conductivity
through resistive sensors.
Applications in the field of biology, chemistry, engineering and others.
No battery required
Free access to the source code
PACKAGE CONTENT
- 1X Thermistor Data Logger (TDL) Revision B (Controller)
- 8X calibrated temperature probes (thermistors) with 1m wire
- 1X calibration certificate
- 1X USB cable, male-to-male, 1m length, OTG
- 1X flat mini-screwdriver
- 1X high-accuracy resistor, 10 kΩ+/- 0.1% (can be used to verify calibration of the TDL)
- 1X cotton rope, 3mm dia., for humidity measurement
- 1X photoresistor (GL5516, CdS type, visible light) (warning: this item contains cadmium)
- 1X extension wire, 28 AWG, 2m length
REQUIREMENTS
- Minimum Hardware: CPU: 1 MHz; Memory: 250 MB RAM.
- Internet Access with Internet Explorer 9 or higher
- 1X USB port (2.0 or 3.0)
- Operating system: Windows®7 and newer, Mac OS X®, Linux®, Android® (See details below)

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- If using a smartphone, “host capability” and a corresponding USB adapter are required.
- Wire-stripper for 28 AWG wire size
SERIAL COMMANDS
In order to interact with the TDL, type in some of the following keywords at the top of the ‘Serial
Monitor’ window and then click ‘Send’. Note that the commands are not case-sensitive.
INTERVAL: The command ‘INTERVAL’ allows adjusting the acquisition rate of all active sensors. The
program will wait for the user to enter a value between 1 and 96 400 000 ms (24 hr). Enter the value ‘0’
to force maximum speed, which will vary depending on the number of active probes. The default factory
value is 1000 ms (1 second).
CELCIUS: The command ‘CELCIUS’ tells the device to display temperatures in Celsius (°C) units. Unit is
stored in the permanent memory (EEPROM) and will be remembered after a shutdown or reset of the
device. Celsius is the default factory setting. No confirmation or further instructions are required.
FAHRENHEIT: Display temperature in Fahrenheit (°F) units. No confirmation or further instructions are
required.
KELVIN: Display temperatures in Kelvin (K) units. No confirmation or further instructions are required.
RESISTANCE: Output resistance values along with temperatures. No confirmation or further instructions
required.
COEFF: Print out the Steinhart-hart coefficients presently stored in the controller memory. No
confirmation or further instructions required.
ERASE: Erase the EEPROM memory and return to the factory settings (RATE 1000 ms, Celsius units). No
confirmation or further instructions required.
SENSORS: “TPTPTPTP” , T stands for temperature sensor, P stands for photoresistor
HUMIDITY: Relative humidity is calculated by post-treatment of the sensors data. A dedicated string
called humidity informs the micro-controller of which channels are dry bulb temperature sensors and
which ones are wet bulb temperatures sensors.
Letters (A,B,C...) identify the dry bulb temperature sensors.
Digits (1,2,3...) identify wet bulb temperature sensors.
'0' identify the channels which are not concerned with humidity measurements.
The factory setting is ‘00000000’.
Example #1: 'ABCD1234'
This is the maximum number of independent humidity measurements that you can do with one TDL
device
Example #2: 'AB001200'
This is an example of two humidity measurements and 4 channels not concerned with humidity
measurements (could be surface temperatures or

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Eample #3: 'A0001200'
This is an example of vector that will generate an error. The program will therefore keep the previous
parameters.
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Figure 1 TDL components layout

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QUICK START: First experiment using the TDL and a computer
Required time: 30 to 90 minutes.
1- Get the TDL parts out of the box.
2- Connect the USB-cable from the TDL to the computer. The PWR (power) green light on the TDL
should light up.
3- If not already the case, connect each thermistor in its dedicated channel with the provided
screwdriver. This type of probe has no polarity, so it can be either wire in each hole of the
channel connector. Make sure that the thermistor ID fits with the channel in the source code.
Make sure that the contact is solid by pulling on each wire.
4- Download the latest version of the Arduino Software IDE for your OS on the Arduino official
website (www.arduino.cc). Follow the instructions provided by the website.
5- Launch the IDE software and select the device the software will talk to. Go to Menu -> Tools ->
Port -> dev/ttyUSB0
a. The exact port name might vary depending on your system. (ex: ttyUSB1, ttyUSB2).
6- Go to Menu -> Tools -> Serial Monitor. A new window should pop-up.
7- If this is not already the case, in the Serial Monitor window, tick the case ‘Show Timestamp’.
Otherwise, the data you save at the end will have no timestamp.
8- At first, the data being displayed on your screen will be gibberish, because the baud rate is
wrong. On the bottom right, set the baud rate to 115200 (program default is 9600). Also, select
‘Carriage ending’.
9- Readable data will start coming in. The typical output in the Serial Monitor window should look
like Figure 1.
10-If you want, before starting your experiment, you can clear the window by clicking on ‘Clear
window’ in the bottom right of the window.
11-You can now proceed with your experiment (ex: dip all 8 probes in a hot cup of water). Clothes
clamp and scotch tape can be useful to hold your probes in place.
12-As the experiment unfolds, watch the data accumulate in the Serial Monitor window. Each time,
the TDL sends data, the light ‘TX’ on the controller should blink very quickly.
13-When you have gathered all your data, untick the case ‘Autoscroll’. This will prevent the screen
from moving while you select your data.
14-Press “CTRL + A” to select all text. Then copy by pressing “CTRL + C”.
15-Open a text editor and paste all text by pressing “CTRL + V”.
16-Save the text file on your Desktop (ex: test_1.txt). This is an important step, since the data
within the Serial Monitor is not recorded permanently.
17-Open Microsoft Excel or, alternatively, a free spreadsheet software (e.g. LibreOffice Calc).
18-Go to Menu -> Data -> From text. Select the text file.
19-The delimiter should be the ‘space’ character.
20-Tick the box ‘Treat consecutive delimiters as one’. Click Finish.
21-Import data to ‘Existing Worksheet’.
22-Adjust the ‘timestamp’ column cell format to ‘Short Date’ in order to display time properly.

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23-You can now create graphs with your data. For example, you might create a Line graph with the
column ‘Time’ as the x-axis and temperature “T1” as the y-axis.
Note #1: Do not switch the thermistor channels unless you update the coefficients accordingly.
Note #2: Avoid impacts on the probe and the controller to maintain their accuracy and functionality. Do
not exceed the maximum temperature to maintain the accuracy of the probe because strong thermal
expansion plays a role in the gradual drift of the probe properties and accuracy.
Figure 2 Connecting the thermistors to the controller (left) and adjusting the Serial Monitor options (right)
Figure 3 Example of data post-treatment with Excel

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Figure 4 Typical output from the TDL device in the Serial Monitor of the Arduino Software. In order you can see: timestamp, measurement ID, temperatures 1 to 8, resistance
values 1 to 8.

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HOW TO UPLOAD THE SOURCE CODE TO THE TDL.
The TDL already comes ready-to-use, but you might want to make some changes to the source code or
use the latest release.
1- Download the latest source code on the Jericho website.
2- Open this code file with the Arduino IDE software.
3- Make the desired modifications to the code, if any.
4- Before uploading to the TDL, you need to copy, by hand, the thermistor coefficients associated
with your device into the source code.
5- Connect the Arduino to the USB port
6- Make sure that the proper USB port is selected by the software.
7- Compile and upload the code to the TDL.
For more help, visit arduino.cc or ask the community: the Arduino platform is very common worldwide.
HOW TO LOG DATA TO FILE EASILY
The Arduino IDE can hold large quantities of data inside the serial monitor window. However, this data is
kept in memory temporarily, and eventually the data has to be copied to a text file for permanent
storage. There is alway a chance that the computer or program would shutdown before doing that
operation. It is therefore best to save data as we go to a text file. There are a few different ways to log
the data, depending on your setup and skills.
For Linux users, the ‘logging script’ can be used.
1- Download the latest ‘logging script’ from the Jericho website.
2- Open a new Terminal window.
3- Go to the script folder.
4- Launch the script.
5- After a few seconds of data logging, open the text file to make sure that data is being saved.
6- (Optional) Launch the gnuplot script in a second window for a live visualization of the data.

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ADDITIONAL DOCUMENTATION AND FILES
1- TDL-Design-Explained.pdf
2- TDL-Code-Architecture.pdf
3- TDL-Source-Code.pdf
4- TDL-Calibration-Procedures.pdf
5- TDL-Applications-List.pdf
6- TDL-Accuracy-calculations.pdf
7- TDL-Measuring-humidity.pdf
8- TDL-Measuring luminosity.pdf

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PRODUCT SPECIFICATIONS
OVERALL SYSTEM
Jericho model number: TDL-RevB
Multiplexer: CD74HC4067
USB cable length: 1m
Number of channels: 8
Thermistor wire gauge: 28 AWG, style UL2468, 300V, 80°C/176°F. Tinned copper multiple conductors.
Indoor/Outdoor use: Yes (Weatherproof)
Waterproof: Probe only.
Overall measurement accuracy: +/- 0.5°C (+/- 1°F) in the 0-100°C range (-32°F to 212°F)
Maximum resolution (temperature): 0.01°C (0.01°F)
Maximum resolution (resistance): 2 Ω
Measurement range (resistance): 0 Ω to 10 MΩ
Output format: ASCII, Serial monitor
Storage: Varies with computer/smartphone. Typical: 1,000,000 temperatures = 28 MB text file.
Minimum measurement interval (using 1 probe): 3 ms (340 S/s)
Minimum measurement interval (using 8 probes): 400 ms (2 S/s)
Maximum measurement interval: 96 400 000 ms (24 hr)
Default microcontroller baud rate: 115200 bits per sec
Calibration type: end-to-end 3-point characterization (ice bath (0°C / 32°F), warm bath (typically
37°C/99°F), steam point (typically 100°C/212°F)
CONTROLLER
Outside dimensions (controller): 115 X 51 X 19 mm (4.5 X 2.0 X 0.8 in)
Weight (Controller only): 40 g
Voltage input: 5V DC (USB)
Operating temperature (controller): -40°C to 85°C (-40°F to 185°F)
Maximum operating relative humidity for the controller: 95%
Microcontroller: ATmega328p (with old bootloader)
Analog-to-digital converter (ADC) accuracy: 10-bit
Tension divider circuit resistor value: 10 kΩ+/- 0.1%
Microcontroller total memory available (Flash): 30.7 kB
Space taken by the native program: 13.6 kB
SRAM memory available: 2 kB
SRAM memory used by the native program (global variables): 1680 kB (82% of the total)
EEPROM memory available: 1 kB
PROBE
Probe-Murata NXFT15XH103FA2B100, NTC thermistor 10kΩ, very small diameter

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Probe-Operating temperature range: -40°C to 125°C (-40°F to 257°F)
Extension wire length: 1m (3 ft)
Extension wire operating temperature range: -30°C to 110°C (-22°F to 230°F)
Probe-Thermal time constant (Probe): 4 sec
Probe-Tolerated pH: 3 to 10 for 7 days
Probe-Minimum tolerance to saturated salty water @ 20°C: 14 days
Probe typical power consumption per probe (max speed): 0.1 W
Probe typical power consumption per probe (1 S/s): 0.01W
REFERENCES
Arduino Uno Rev3, Digikey,
https://media.digikey.com/pdf/Data%20Sheets/Arduino%20PDFs/A000066_Web.pdf
ATmega 328p datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-7810-
Automotive-Microcontrollers-ATmega328P_Datasheet.pdf
Processing language official website, Processing.org
Free Arduino tutorials, https://www.tutorialspoint.com/arduino/
CONTACT
For more information, tutorials, FAQ, software updates, accessories and replacement parts, please visit
us at jericholab.com. We also appreciate you leaving comments and suggestions.
WARRANTY
30-day full refund including shipping, no questions asked. 1-year limited warranty on defects. Made In
Canada with International Components.
ABOUT JERICHO LAB
Jericho is a company based in Montreal, Canada. Our mission is to provide low-cost high-accuracy
scientific equipment to students, scientists and engineers. The Rose of Jericho (Anastatica
hierochuntica) is a desert plant that can survive years of complete desiccation.

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ABOUT ARDUINO
The TDL is compatible with the Arduino language, which is based on the ‘Processing’ language, which
itself is similar to the C language. Most of the C/C++ core language can be used with the TDL device and
the Arduino IDE software. You can create classes, use inheritance, composition, and other
functionalities, but STL and exceptions cannot be used. Arduino first appeared around 2005 and is now
used worldwide by over a million users. Jericho is not endorsed or linked in any sense with the Arduino
company. The hardware from Arduino is distributed via a Creative commons license. Arduino clones are
produced by hundreds of manufacturers around the world, with different qualities.
This product is non-recyclable. Please do not throw away this product to garbage. Please send your
Jericho product to your local electronic waste drop-off site.
FREQUENTLY ASKED QUESTIONS (FAQ)
- What is a thermistor?
A thermistor is a tiny passive device which has an electrical resistance that varies with the temperature
of its material.
- Why do I have to connect the thermistor to a specific channel?
Each thermistor has unique parameters called Steinhart-Hart coefficients. Each channel is associated
with a specific set of coefficients. Therefore, switching the thermistors would provide inaccurate
temperature readings.
- One channel output is “-273.15”. What does it mean?
The channel is empty or opened (false contact).
- Can I use the TDL to do something else?
Yes, you can modify the product, software and hardware to add or remove capabilities. However, any
physical modification of the device will void the warranty.
- I dropped the TDL in the water, what should I do?
Water will create short-circuits that will render the device unusable temporarily. Drop it in dry uncooked
rice with closed container for 24 to 48h to remove humidity, like you would do for a smartphone. It
should work again.
- What other software than Arduino Software can I use to control the TDL device?
The IDE software provided by Arduino is specifically designed for Arduino and Arduino-compatible
devices and provides an easy interface to beginners and advanced users. However, some users might

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prefer to use more professional programming tools. A free option that is often recommended is the
software Atom, combined with the Platformio add-on.
- Can I control something with the TDL?
Yes, with some supplementary work. It is possible to use the free outputs on the microcontroller to
send control signals. However, this requires coding and the total memory available on the
microcontroller is limited.
- Can I paint the controller enclosure?
Yes, it should cause no problem if you paint the outside surface.
- Can I use any smartphone?
No. The smartphone needs to have host capability. When you connect a smartphone and a computer,
the smartphone acts as a slave and the computer as a host. When you connect a smartphone and a TDL
device, the smartphone acts as a host and the TDL acts as a slave. However, not all smartphones are
able to behave as a host.
- What is an ‘OTG cable’ and a ‘host capability’?
- Can I use a solar panel with the smartphone?
Yes, however it must provide a 5V regulated voltage. In the OTG setup, the solar panel would replace
the 5V adapter. Jericho has not tested any solar panel setup yet, but in theory it would work.
- Is the calibration of the thermistors NIST traceable?
- Should I thin the wire endings to be used with screw terminals?
No, professionals do not thin the wires due to different thermal expansion coefficients which overtime
can create
-How to make surface measurements underwater ?
-How to hold the TDL on a wall ?