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This project pairs an LM35 analog temperature sensor with Bolt IoT hardware and cloud monitoring to track temperature and flag unusual readings. It is best understood as a learning prototype: the available project materials do not establish that the complete system is calibrated, validated, or suitable for regulated pharmaceutical storage.
What the LM35 and Bolt IoT project does
The Hackster.io project listing describes a temperature-monitoring and anomaly-detection build for a pharmaceutical tablet case, using an LM35 sensor and Bolt IoT. The listing does not provide enough accessible implementation detail to confirm every wiring choice or software step, so those specifics should be checked against the project’s complete instructions.
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At a high level, the LM35 produces an analog signal that changes with temperature. Bolt samples that signal and sends readings to cloud services, where they can be plotted and monitored. Bolt IoT’s 2019 tutorial documents a workflow that connects the sensor’s supply and ground to the Bolt device, connects its analog output to the Bolt analog input, and configures cloud visualization and alerts. The interface described is from that tutorial, not a guarantee of current Bolt cloud labels or screens. Hackster.io Bolt IoT: Alert Me on Temperature Data
How temperature readings and anomalies are handled
Converting the LM35 signal
Texas Instruments specifies the LM35’s linear scale factor as 10 mV/°C. That means its output voltage corresponds to Celsius temperature, but the voltage-to-temperature calculation in a particular build depends on the board’s analog-to-digital converter range, reference voltage, sensor variant, and circuit. A conversion formula from one tutorial should not be assumed to apply unchanged to every configuration. Texas Instruments LM35 product page
#1 Best Overall
- Rated for full −55˚ to +150˚C range
- Suitable for remote applications
- Operates from 4 to 30 volts
- Low self-heating, 0.08˚C in still air
- Nonlinearity only ±1⁄4˚C typical
Alerts and anomaly detection
A related capstone document describes sending email alerts when temperatures cross thresholds and using Z-score analysis to identify anomalous readings. A Z-score measures how far a reading is from a data set’s mean in standard-deviation units; how useful it is depends on the data and the chosen threshold. The available description does not establish the project’s exact alert thresholds, Z-score settings, or performance, so those details should not be treated as verified operating results. Capstone document
What the LM35 specifications do—and do not—tell you
Texas Instruments lists an LM35 operating range of −55°C to 150°C and an ensured accuracy of 0.5°C at 25°C. Those are component specifications, not a measured accuracy claim for the assembled monitoring system. Sensor placement, calibration, the analog measurement circuit, installation conditions, and data handling can all affect the system’s readings and reliability. Texas Instruments LM35 product page
Rank #2
- BOJACK High Precision Celsius Temperature Sensor
- Operating Voltage:2.7 V - 5.5 V
- Rated temperature range: -40 °C-+125 °C
- Accuracy: ±2°C
- Scale factor: 10 mV/8°C
Parts and setup considerations
- LM35 sensor: The project’s temperature sensor; confirm the exact sensor variant before using a wiring diagram or conversion calculation.
- Bolt Wi-Fi module: The project materials identify Bolt hardware, but do not establish the exact model or its current availability. Check the project instructions and current product documentation before purchasing.
- Breadboard and jumper wires: Generic supporting items for prototyping the connections.
For setup, follow a diagram that matches both the LM35 variant and Bolt board. Check power, ground, and analog-input connections before powering the circuit; then verify that cloud readings change plausibly as the sensor temperature changes. A plotted value is not proof of calibration.
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1Clear out junk files and repair common Windows errors2Fix the driver behind crashes, sound loss and screen glitches3Repair Windows errors before they cause bigger problemsIs this suitable for pharmaceutical storage monitoring?
The available evidence supports treating this as a learning prototype, not a validated system for regulated storage. It does not show calibration against a traceable reference, validated sensor placement, environmental qualification, a documented alarm-response process, audit-trail validation, or regulatory approval. The temperature ranges and time restrictions in the related capstone document are scenario claims, not verified current regulatory requirements; consult the relevant regulator and product-specific storage guidance for applicable requirements.
Rank #3
- Specified −40°C to +125°C, operation to +150°C
- Low voltage operation (2.7 V to 5.5 V)
- Stable with large capacitive loads
- Less than 50 μA quiescent current
- Qualified for automotive applications
Bolt IoT separately markets Blake for facility temperature and humidity monitoring, including pharmaceutical and diagnostics settings, with alerts and anomaly-detection features. That is a distinct commercial offering, not the same thing as the LM35/Bolt DIY tutorial, and its suitability for any regulated use must be established from its own documentation and the applicable requirements. Bolt IoT Blake
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.If you adapt the prototype
Choose a sensor based on its temperature range and accuracy across the temperatures you actually need to monitor, its interface, calibration requirements, and suitability for the installation environment. Evaluate an IoT platform for connectivity, alert delivery, data retention, security, and any validation requirements relevant to its use. The project materials do not compare alternative sensors or platforms.
Quick Recap
Best Value
- Type: Precision Temperature Sensor.Measuremen accuracy +/- 0.25¡ãC
- Operating voltage: DC 4 ~ 30 V;Rated for full ?55? to +150?C
- Model: LM335Z, suitable for remote applications
- Applications: Ideal for temperature sensing and control applications in a variety of electronic devices.
- Package: Available in a TO-92 package for easy installatio
Rank #4
- Precision Temperature Measurement: Linear 10mV/°C output (0V at 0°C) with ±0.25°C accuracy at 25°C for reliable data
- Plug-and-Play Compatibility: 3-pin interface works compatible with Microbit and most microcontroller expansion boards 5VDC powered
- Robust Design: Four 3mm mounting holes secure the module to prototypes or enclosures; compact size 34×22×9mm, 2.6g
- Wide Operating Range: Measures -40°C to +110°C, ideal for environmental monitoring, DIY projects, and industrial prototyping
- Analog Signal Output: Directly interfaces for real-time temperature logging and control systems, suitable for engineers, technicians, factories, individual DIY, electronic enthusiasts, etc
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