Pycom SDI-12 Host Board

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General Information

Host board Pycom development board (link)
Supported Sensors SDI-12 sensors, Temperature, Humidity
Power Supply USB, Battery, Solar Panel
Misc USB for firmware flashing and debugging
Power switch
Software micropython
Open-source libraries & demo scenarios @ Github
Dimensions (L x W x H) 78 x 57.2 x 16.7 mm
Weight 25 g
Enclosure IP65/IP67

Example Applications

  • Precision Agriculture
    • Soil moisture, Electrical Conductivity, Volumetric Water Content, Temperature
  • Environmental monitoring
    • Water flow, water quality, Temperature, humidity

Sensors Support (Hardware & Software)

On-board Sensors 1 x Temperature/Humidity Sensor (based on the SI7021 chip)
Number of External Sensors Up to 2 (simultaneously)
External Sensor Interfaces Digital: SDI-12 @ 12V
Low energy operation Software-controlled
Sensor models sw support I2C: SI7021 (Board Temperature / Humidity )
SDI-12: Meter’s Teros-12 (Soil), Acclima’s TDR-315H (Soil)


  • Wireless technologies
    • WiFi
    • Bluetooth
    • LoRaWAN
    • NB-IoT/LTE-M
  • IP-based protocols
    • TCP/UDP over IPv4/IPv6
    • MQTT
    • CoAP

Power Supply

USB Port Input Voltage
Micro USB Min. Typ. Max. Units
4.5 5 5.5 V
Battery Port Nominal Characteristics
JST 1 x Rechargeable LiPo 1S1C 3.7-4.2 V
Solar Panel Port Input Voltage
Fixed Terminal Block with push-in connection (no tools required) Min. Typ. Max. Units
5.5 6 6.5 V

Operating Conditions

Operational Temperature 0 – 60 C
Charging Current Limit 330 mA
Maximum Drawn Current 500 mA
Charging Temperature 0 – 60 C

Charging State Indication (LEDs)

Charge cycle state LCO LCG LCR
Shutdown state 1 OFF OFF OFF
Shutdown state 2 OFF OFF ON
Preconditioning ON OFF ON
Constant current ON OFF ON
Constant voltage ON OFF ON
Charge complete-standby OFF ON ON
Temperature fault ON ON ON
Timer fault ON ON ON
Low battery ON OFF OFF
No battery OFF OFF ON
No input OFF OFF OFF


Switch Name Details
S1 Controls power supply to the micro-controller (the battery charging process is not affected)
S2 Tactile switch for activating the micro-controller’s bootloader (needed only for fw upgrade)
SNSR Software-controlled switch for enabling/disabling power supply to sensors on-demand

Hardware Watchdog

Operation Force a power-off/on cycle of the microcontroller after an inactivity period
Control Software-based using a GPIO pin (Enable/Disable)
Inactivity Period Pre-programmed (on demand), from 2 minutes to 30 hours

Energy Consumption Profiling

Battery Voltage Accurate Measurement of battery voltage even at charging state
Current Measurement of drawn current at any state (idle, sensor reading, communication)

External components required/recommended

  • Microcontroller
    • Pycom WiPy 3.0 or LoPy4 or GPy or FiPy (depending on communication needs)
  • Battery
    • 1200 mAh
  • Solar Panel
    • 6V/1W


CE planned
FCC planned
RoHS planned

Custom designs

The existing boards are highly configurable and expandable so if the existing boards do not fit your need, get in contact with us and we will tailor a solution for you with your customizations.