LoRaWAN

RN2903: Using the LoRaWAN™ Library Plug-in for MPLAB® Code Configurator and customising for the AU915 Frequency Plan

The RN2903 Wireless LoRa Module from Microchip ships with an on-board LoRaWAN Class A protocol stack. This stack can be accessed via ASCII based commands over a UART interface. For many, this is the interface of choice, offloading the complexity of the LoRaWAN stack to a dedicated processor contained within the module. Another advantage is Microchip can fully certify the module and stack. I decided not to use the on-board stack for two reasons: Here in Australia, we must use the AU915 frequency plan. Microchip has beta firmware for this frequency plan, but it is not yet publicly available. Developers

LoRaWAN

Microchip RN2903 LoRa Transceiver Breakout Board

A breakout board for Microchip’s series of LoRa transceiver modules: RN2483 fully-certified 433/868 MHz Module (Europe) RN2903 fully-certified 915 MHz Module (North America, Australia) The RN2483/RN2903 LoRa modules contain a Microchip PIC18LF46K22 MCU with a Semtech SX1276 radio transceiver and is intended as a complete certified solution with LoRaWAN Class A protocol stack and an ASCII command interface over a UART connection. However, if you want to get under the hood, MicroChip provide details in the LoRaWAN Library Plug-in for MPLAB Code Configurator User’s Guide on how to target the on-board PIC18LF46K22 and customise the module for your own purposes. RN2903 Pin Out (XLSX) Design Files

Power

ML2032 Coin Cell Charger

This design is intended to recharge Maxell ML2032 Lithium Manganese Dioxide rechargeable coin cell batteries with a nominal voltage of 3.0V. These are ‘special’ coin cell batteries designed specifically as a rechargeable secondary cell. It is not recommended to attempt to recharge a primary CR2032. These cells have not be designed for recharging.  Background Rechargeable replacements of the popular CR2032 3V lithium coin cell battery exist, but one caveat is reduced capacity. The common CR2032 from name brand manufacturers such as Panasonic will have a capacity of approximately 220mAh. Rechargeable replacements of the CR2032 appear to come in a range of different chemistries.