Abstract Sensors are essential to collect a wide range of high-fidelity and reproducible data from livestock farms. On one hand, commercial cameras are capable of recording large videos for post-processing and analysis on edge computers. On the other hand, a variety of electronic sensors and microprocessor chips are commercially available to track the posture and movement of animals in livestock farms. There are inherent tradeoffs in developing and adopting the above sensors, including issues with handling the big data, effective noise filtering, computing at the edge, on-farm resiliency, power usage, and infrastructure costs. In this talk, we will discuss these tradeoffs while understanding the needs of different livestock farms in the context of our research in sensor technologies.

1. An Engineers Perspective on Sensor Development
and Future Applications in Livestock
Session: Genetics, Genomics and Bioinformatics Symposium
March 15, 2022
9:15 AM – 9:45 AM, Room 203
Santosh Pandey
1050 Coover Hall, Electrical & Computer Engineering,
Iowa State University, Ames, IA 50011, PANDEY@IASTATE.EDU
Journal of Animal Science, Volume 100, Issue Supplement_2, May
2022, Page 13, https://doi.org/10.1093/jas/skac064.021

2. Talk Outline
1. Role of Sensors in Precision Livestock Farming (PLF)
2. Need for Customized Sensors
3. Custom Ear-Tag Wireless Nodes with Multiple Sensors
4. Tradeoffs in Attributes, Benefits, and Challenges
5. Conclusion

3. Role of Sensors in Precision Livestock Farming (PLF)
Motivation: Remote monitoring of animal behavior round-the-clock for early
detection of abnormal traits
Types of sensors: On-the-body/on-the-farm; Image sensors/electronic sensors
Types of data: Video and/or audio, public databases, manual records

4. Need for Customized Sensors
i) Commercial sensor systems (hardware and software) are generally expensive and do
not support customization. Third-parties are often involved in various stages of
electronics development and cloud computing/storage.
ii) Custom boards can be built around specific needs of the farm. It takes significant time
and effort but provides control over process flow.

5. Custom Ear-Tag Wireless Nodes with Multiple Sensors
Size, Weight, Cost: In-house customized board with 3.05 cm × 3.05 cm × 1.27 cm (L × W × H)
size, a 5 g weight, and a development cost (hardware only) of around $25 - $35 per board.
Sensor Board Functionalities:
(i) A contactless, infrared temperature sensor (MLX90614) to measure both the ambient temperature and
external body temperature of the pig;
(ii) A 3-axis accelerometer (ADXL345) and gyroscope (ADXRS300) to record data on head tilt and movement,
which is correlated to lethargy or movement disorders;
(iii) A sound sensor (MAX9814) to capture the vocalizations for the identification and classification of call types

6. System-on-Chip: Microprocessor with Bluetooth LE
1. A Bluetooth low energy (BLE) module (nRF51822 SoC) to receive data from the activity
sensors at a pre-selected rate (e.g., 5 samples per second).
2. This BLE module incorporates a, 32-bit ARM Cortex-M0 CPU, 256 kB Flash Memory/16 kB
RAM, and chip antenna.
3. The BLE module is suited for ultralow-power wireless communication at 2.4 GHz by
supporting third-party I2C, UART, and PWM interfaces (refer to nRF51 documentation).
Receiver

7. Batteries and Power Consumption
nRF51822
(Bluetooth)
Accelerometer Gyroscope IR
Thermometer
Mic with
Amp
On 13 mA 30 µA 5 mA 2 mA 6 mA
Off 4.4 mA 0.1 µA 1 µA 6 µA 1 µA
Power Consumption for one complete cycle
𝐿𝑜𝑎𝑑 𝐶𝑢𝑟𝑟𝑒𝑛𝑡 𝐼𝑙 = 13 + 0.03 + 5 + 2 + 6 = 26.03 𝑚𝐴
Battery Life (with Coin Cell Battery: CR2032)
𝐿𝑖𝑓𝑒𝑡𝑖𝑚𝑒 𝐻𝑜𝑢𝑟 = 220 𝑚𝐴ℎ ÷ (𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑜𝑓 𝐼𝑙 𝑎𝑛𝑑 𝐼𝑖) 𝑚𝐴
Data Period 1s 2s 3s 4s 5s
Battery Life
(Hour)
8.45 14.45 18.94 22.41 25.19
𝐼𝑑𝑙𝑒 𝐶𝑢𝑟𝑟𝑒𝑛𝑡 𝐼𝑖 = 4.4 + 0.0001 + 0.001 + 0.006 + 0.001
= 4.40081 𝑚𝐴
Employ power management
strategies and bigger batteries

8. Sensors’ Attributes, Benefits, and Challenges

9. Sensors’ Adoptability Factors

10. In Conclusion….
i) Any degree of customization in sensor technologies provides better control
over the process flow (from data collection to quality checks).
ii) The field of electronic and imaging sensors is constantly evolving, and so
should the hardware and firmware associated with your application.
iii)The SDK firmware setup of the microprocessor with wireless communication
takes the most effort in system design.
iv)Power management is an important aspect of sensor design, besides the
other factors of cost, size, weight, accuracy, resolution, data quality etc.
v) Sensor technology development should be driven by users’ requirements on
the farm, and not vice versa.