Pycom SDI-12 Host Board
General Information
| Host board | Pycom development board |
| 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) |
Communication
- 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 |
Switches
| 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