Main Boards

Main boards SHOULD be the same size as extension boards. Their size and layout is specified in the natWatch platform specification. In some special cases, the board outline MAY be changed to accomodate various enclosures and boxes, eg. to allow easier fastening.

There SHOULD NOT be any DAQ features on the main board itself (otherwise it ruins the basic board stacking concept). However, there MAY be some very generic power and comunication interfaces like a common industrial 24V power supply or a sub-1GHz radio transceiver for communication.

In some cases a battery MAY be mounted directly on the main board. In this case a MPPT or micro-USB charging MAY be implemented directly on the main board.

Name Form factor Description Status
plumpot-cellular hald-width, half-depth A basic board for remote data acquisition using cellular networks. STM32F401/STM32F411, SPI flash for configuration and firmware updates. Optional power supply and sub-1GHz radio modem. Meant to be used as a cheap solution when a cellular network is available. No local storage is usually needed, no microSD slot is available. Uses a cheap and mainstream MCU. 1.0.0 prototypes available, field test ongoing from 11/2017.
plumpot-lp hald-width, half-depth Low power main board for local data logging. STM32L4 MCU, onboard SPI/qSPI flash for configuration and firmware updates + optional microSD slot for logged data. No communication interface is available. 1.0.0 prototype PCB manufactured
plumpot-mp hald-width, half-depth Medium power main board for data acquisition and data processing. STM32L4+ MCU (SMPS version running at full speed) + hyperflash S26KS + hyperbus DRAM S27KS. 1.8V design. MicroSD slot for data logging. No power supply or communication interface is available. Usually this main board should be part of a more complex system with dedicated boards for DAQ and communication. preview/design

DAQ boards

Slow process DAQ (low sample rate):

  • DMM style universal measurement board (DC voltage, DC current, AC voltage, AC current, resistance, optional capacitance/inductance)
  • multi-channel low-accuracy resistance-to-digital converter (NTC temperature measurements)
  • multi-channel RTD high resolution/accuracy temperature measurement
  • multi-channel low accuracy capacitive sensing (moisture/water content probes)
  • 3-channel high accuracy capacitive sensing (water level measurement, 1 measurement probe + dry and wet reference probes)

Fast DAQ/data processing:

  • 1Mohm scope input digitizer (low resolution + fast, high resolution + slow)
  • ultrasonic driver/receiver
  • gps-synchronized 50Ohm input digitizer (VLF reception, acoustic cameras, etc.)
  • IEPE input digitizer (acceleration measurement)
  • SDR receivers for scientific purposes (LF, HF, <1GHz, …)
  • TDR/FDR for dielectric measurements
  • 2 channel 192kHz audio ADC (acoustic cameras, environment monitoring, sound recording)

Sensor interfaces

Analog sensor interfaces:

  • 0-5V, 0-10V sensors
  • 4-20mA sensors
  • analog optical sensor inputs

Digital sensor interfaces:

  • SDI sensors
  • CAN sensors
  • I2C sensors
  • 1Wire sensors


  • internal environmental monitor (accelerometer, temperature/humidity, sound, tamper detection, light detection, etc.)

Wired communication

Communication with master controllers and/or slave devices:

  • RS232 ports
  • RS485 ports
  • CAN
  • Ethernet

Wireless communication

  • WiFi
  • BT
  • sub-1GHz radio modems
  • cellular networks
  • IoT neworks (LoRaWAN, SigFox)
  • satellite modems

Power management boards

Power management boards include:

  • isolated and non-isolated power supplies
  • boards holding accumulators and batteries of various types
  • battery chargers, MPPT chargers
  • converters for energy harvesting

Data storage boards

  • industrial NAND flash storage
  • backed-up RAM/SRAM/DRAM for large buffers
  • EEPROM/NOR flash storage (high erase cycle count)
  • consumer microSD card readers (with mirroring)
  • industrial CF card readers
  • natwatch-roadmap/index.txt
  • Last modified: 2019/02/27 21:08
  • by qyx