Walrus Board

Walrus is an open-source platform for battery-powered sub-GHz and 2.4 GHz radio communication

Dual Radios

Walrus has two radios, accessed over SPI:

• RFM69HCW transceiver for 900 MHz (also usable at 433 MHz)
• CC2500 transceiver for 2.4 GHz

Designed for Raspberry Pi Zero W

• Raspberry Pi Zero form factor
• 40-pin Raspberry Pi GPIO connector
• HAT EEPROM

Battery Power Management

• JST PH 2.0mm connector for 3.7 V LiPo battery
• 500 mA battery charging when Raspberry Pi is connected to 5 V via micro-USB
• hard power-off via pushbutton or GPIO disconnects battery from Raspberry Pi
• programmable power-on via RTC alarm

Other Peripherals

Walrus has the following I2C devices:

• Real-Time Clock (M41T62LC) with power-on alarm
• Analog-Digital Converter (ADS1015) for battery voltage and charge current measurement
• 3-axis Accelerometer (LIS3DH) with single and double-tap detection