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This Wiki page contains additional information for the Modtronix NZ32-ST1L-R1 board. Please feel free to register and improve this page - user contributions are greatly appreciated!

This small board is designed for very low power applications. It is assembled with a STM32L151RC Microcontroller. It has an on board battery charger for a 3.7V Li-Ion or Li-Polymer battery. System 3.3V is generated via an on board 3.3V regulator with very low current consumption. This regulator provides 3.3V at 800mA which is available for any custom circuitry.

This board has 3 iMod port for adding Modtronix iMod modules. A common use for this module is to add a LoRa SX1276/SX1278 Wireless iMod module for battery powered, low power wireless applications.

Board can be powered via USB connector, external battery(plugged into JST PH 2.0mm connector) or external 5V provided via pin headers. If higher voltage is required, the pm35SS-5 iMod module can be added, allowing up to 28V supply. This can for example be connected to solar panels to power and charge the battery.

We are in the process of adding this board to available platforms on This will enable online programming using the free mbed compiler. Additionally online projects can be exported an built on local computer using free IDE(CoIDE, Eclipse, System Workbench, EmBitz, ….) and free GNU GCC ARM C/C++ compiler.

Schematic and Pinout Diagram

The PDF schematics for this board is available here. A picture of the top PCB layout can be downloaded here.


Programming and Debugging

This board can be programmed using the following methods:

  • Using with the DEVKIT-ST1L or DEVKIT-2ST1L Development Kit. These development kits have a connector for the PGM-NUCLEO programmer and debugger.
  • Using the STM32 built in USB or UART bootloader.

With DEVKIT-ST1L or DEVKIT-2ST1L Development Kit

The best fastest way to program and debug this board it to use it together with the the DEVKIT-ST1L or DEVKIT-2ST1L Development Kit. These development kits have a connector for the PGM-NUCLEO programmer and debugger. When connected to USB port of PC, the PGM-NUCLEO creates the following USB interfaces

  • ST-LINK/V2-1 Programmer and Debugger
  • A USB MSD(Mass Storage Device) drive for Drag and Drop programming
  • A USB Virtual Com Port (virtual serial port) connected to PB10 and PB11 of STM32 MCU.

The ST-LINK/V2-1 interface is used by most IDEs (CoIDE, System Workbench, TrueSTUDIO, uVision, ….) for programming and debugging STM32 MCUs. The USB MSD enables drag and drop programming. The PGM-NUCLEO also creates a Virtual com port (CDC interface) that enables communication via UART3 located on the PB10 and PB11 ports of the MCU. A standard serial terminal application (like HyperTerminal for example) can be used on the computer to connect to this victual com port.

For details, see the PGM-NUCLEO Wiki page.


The Modtronix PGM-NUCLEO can be used to program and debug the STM32 CPU via the ST-LINK/V2-1 interface. This enables programming and debugging from many IDEs, like CoIDE, Eclipse, System Workbench, TrueSTUDIO, EmBitz, uVision and others.

USB Bootloader

The STM32 chip used on this board has a bootloader programmed into ROM, meaning it is always available! To enter bootloader mode, the “BOOT” button must be pressed down during power up or reset(toggle reset button). After this, the firmware can be upgraded by using a DFU USB programmer. To program the board via USB using the DFU programmer, the HEX or BIN file must first be converted to a DFU file. This resulting DFU file is then used to program the STM32 board.

Convert HEX or BIN file to DFU file

  • Download and install v3.0.3 of the DFU app(STSW-STM32080) IMPORTANT!!! V3.0.4 has a bug, and does not work for generating DFU files! We used V3.0.3, located here.
  • Start “DFU File Manager v3.0.3” app. Open HEX file, and click “Generate” button. This will generate a DFU file.

Program STM32 board with generated DFU file

  • Download and install DFU app (STSW-STM32080). For programming DFU to STM32 chip, we used v3.0.4! Search for “STSW-STM32080”. At time of writing this, it was located here.
  • Start “DfuSe Demonstaration” application.
  • Power up NZ32-ST1L while holding “BOOT” button down. The “DfuSeDemo” application should now show a device in “Available DFU Devices” box.
  • Click “Choose” button, and select *.dfu file. Do NOT use th “Choose” button in “Upload Action” section!
  • Click “Upgrade” button, and upgrade firmware. Do NOT use th “Upload” button in “Upload Action” section, this is to download the current firmware on the device!

Wireless Interface

This board has 3 Modtronix iMod ports. One on top, and two at the bottom of the board. This enables a wireless interface to be added to be board, like WiFi, Bluetooth or SX1276/SX1278 LoRa Wireless module. The SX1276 incorporates Semtech's LoRa technology, making very long range communication (over 10km) possible at low power! The photo below shows the NZ32-ST1L with an inAir SX1276/SX1278 LoRa iMod assembled. The inAir modules are available in 433MHz, 868MHz and 915MHz.

products/nz/nz32-st1l-r1.txt · Last modified: 2015/05/29 22:43 by modtronix