Penguino Feather – SAMR34 SiP based LoRa DevBoard
What is Penguino?
Penguino is a small 0.9 in. x 2 in. ATSAMR34J18 LoRA System-in-Package (SiP) based, @Adafruit Feather styled development board. It’s a two board construction (an RF module and a breakout board) IoT rapid prototyping platform for LoRa end-node applications. All of its design files and example firmware can be found on my GitHub.
Penguino RF Module
ATSAMR34J18 LoRa SiP is deigned as a standalone RF module and is soldered on top of the breakout board. The RF module consists of all the essential components for RF matching, switching and power filtering parts and covers frequency range of 862 to 1020 MHz.
Specs:
- ATSAMR34J18 LoRA System-in-Package (SiP) based RF module
- ARM Cortex M0+ MCU & SX1276 LoRa Radio
- 256KB Flash, 40 KB RAM
- Power Output: up to +20 dBm
- Frequency Range: 862 to 1020 MHz
- Sleepwalking Mode: ~2.3 μA
- Backup mode: ~810 nA
- IO pins: 27
- Module Dimensions: 0.65in. x 0.55in. (16.5mm x 14mm)
Penguino Feather Breakout
The Feather style breakout board comes in a breadboard friendly layout and it contains following items.
- Li-Po battery charging IC (MCP73831 or TP4054)
- Indicator LEDs for Charge (orange), Status (red) and Power (blue) (w/ cut-off jumpers)
- 3.3V low Iq LDO
- Low-voltage battery cut-off supervisor IC (3V)
- USB connector with protection/filtering circuit
- 0.75 A resettable fuse
- ADC Battery monitoring voltage divider (w/ cut-off jumpers)
- SMA* and u.FL antenna connectors (*antennas are not included)
- 10-pin SWD programming header
- Standalone current consumption: ~7 μA (when all LEDs are disabled by cutting their jumpers)
- Breakout dimensions: 2 in. x 0.9 in. (50.8 mm x 22.8 mm)
Firmware Development (the official route)
As a development environment the defualt IDE is Atmel Studio v7 with Atmel-Software-Framework (ASF) >v3.45. Please follow this installation instructions that I put together to correctly setup the ASF v3 development framework. Unfortunately ASF v4 with ATMEL START configuration GUI is currently not supported for SAMR34 devices. The board can be flashed using an ATMEL-ICE or a J-Link programmer/debugger.
Serial communication with the board can be established either over the Rx-Tx pins (see the pinout diagram) using USB to Serial converter (i.e. FTDI, CH340G, etc.) or with the on-board USB. To activate the on-board USB as Virtual COM Port (VCP) one should use Atmel USB Device CDC Application example provided by the ASF. There are several VCP example projects with and without the LoRaWAN stack included.
Firmware Development (open-source route)
BastWAN and Wiz-IO are two great projects which are focused on SAMR34. BastWAN focuses on the Arduino port of SAMR34, while Wiz-IO is offering both Arduino and baremetal options on the PlatformIO platform.