Watermelon IoT Board

Pictured above is an early prototype. The final board will have quite some differences – mainly some components have been moved to allow better enclosure compatibility.

[heading header_type=”h1″ header_size=”super” header_weight=”hairline” header_align=”left” header_underline=”bordered-header”]Watermelon IoT development board[/heading]

Watermelon is an affordable, DIY-friendly, compact embedded development board with pure connectivity in mind. It’s about twice the size of a PI, but it comes with way more juice! Seven fully powered USB 2.0 host ports and one USB-OTG are on-board, so there’s no need for a separate USB hub. You can even power attached devices with an additional LIPO battery to have uninterruptible power.

Lots of I/O make it easy to attach your existing gadgets, modules and sensors. A battery backed realtime clock, a SATA connector, LIPO charging circuit and WiFi are on-board, to help you to turn your prototype into a product easily.

Watermelon is the perfect connectivity hub for your next Internet Of Things project and always-on device prototype – or a base for your next commercial product. All the components you’ll need for real-life applications are included.

[heading header_type=”h1″ header_size=”normal” header_weight=”regular” header_align=”left” header_underline=”bordered-header”]Performance[/heading][feature show_icon=”true” shape=”hex” title=”CPU” icon=”dashboard”]Allwinner A20 ARM Cortex-A7 dual-core ARM @ 1GHz[/feature][feature show_icon=”true” shape=”hex” title=”GPU” icon=”dashboard”]Dual-Core Mali 400[/feature][feature show_icon=”true” shape=”hex” title=”RAM” icon=”dashboard”]1GB DDR3[/feature]
[heading header_type=”h1″ header_size=”normal” header_weight=”regular” header_align=”left” header_underline=”bordered-header”]Networking[/heading][feature show_icon=”true” shape=”hex” title=”Ethernet” icon=”cloud”]100Mbit native ethernet[/feature][feature show_icon=”true” shape=”hex” title=”WiFi” icon=”wifi”]802.11n[/feature][feature show_icon=”true” shape=”hex” title=”Bee Socket” icon=”signal”]Bee socket for Digi’s XBee modules, or one of the many Bee-compatible wireless-modules such as RF, Bluetooth, GPS, and more.[/feature]
[heading header_type=”h1″ header_size=”normal” header_weight=”regular” header_align=”left” header_underline=”bordered-header”]Connectivity[/heading][feature show_icon=”true” shape=”hex” title=”USB” icon=”share-alt”]7 USB 2.0 hosts and 1 USB-OTG port, all fully powered with current limiter (500mA per port). The ports can also provide power when the board is powered by a LiPo battery.[/feature][feature show_icon=”true” shape=”hex” title=”GPIO” icon=”sliders”]160 GPIOs including Audio in/out, camera interface, I2C, SPI, PWM[/feature][feature show_icon=”true” shape=”hex” title=”UART Debug Console” icon=”terminal”]3-pin UART connector to access the board via debug console. Hook up your serial-usb adapter easily.[/feature]
[heading header_type=”h1″ header_size=”normal” header_weight=”regular” header_align=”left” header_underline=”bordered-header”]Display[/heading][feature show_icon=”true” shape=”hex” title=”HDMI” icon=”desktop”]FullHD video support (1080p) with audio[/feature][feature show_icon=”true” shape=”hex” title=”LVDS Display Connector” icon=”desktop”]40-pin connector to connect LVDS / LCD displays[/feature][feature show_icon=”true” shape=”hex” title=”VGA” icon=”desktop”]VGA is available on the GPIO connectors. You need to create your own adapter if you want to use it.[/feature]
[heading header_type=”h1″ header_size=”normal” header_weight=”regular” header_align=”left” header_underline=”bordered-header”]Storage[/heading][feature show_icon=”true” shape=”hex” title=”SSD” icon=”hdd-o”]4GB NAND Flash[/feature][feature show_icon=”true” shape=”hex” title=”MicroSD” icon=”floppy-o”]microSD card slot with push-to-release mechanism[/feature][feature show_icon=”true” shape=”hex” title=”SATA” icon=”database”]SATA connector and a 5V power jack for SATA-devices[/feature][feature show_icon=”true” shape=”hex” title=”EEPROM” icon=”bug”]2KB EEPROM for MAC address storage and more[/feature]
[heading header_type=”h1″ header_size=”normal” header_weight=”regular” header_align=”left” header_underline=”bordered-header”]Power[/heading][feature show_icon=”true” shape=”hex” title=”LiPo battery” icon=”bolt”]Battery connector with charging circuit and charge-state LED[/feature][feature show_icon=”true” shape=”hex” title=”5V Power Jack” icon=”plug”]power the board with a 5V power supply. An attached LiPo battery is charged automatically when powered by this connector.[/feature][feature show_icon=”true” shape=”hex” title=”Energy Efficient” icon=”leaf”]Draws 4W when idle and 7W under full load. Decoding 1080p video using 4.5W only. These measurements were made at the power socket, hence include inefficiencies of the 5V power supply.[/feature]
[heading header_type=”h1″ header_size=”normal” header_weight=”regular” header_align=”left” header_underline=”bordered-header”]Extensibility[/heading][feature show_icon=”true” shape=”hex” title=”Shields” icon=”bars”]compatible headers for shields made for Olimex’s OlinuXino Lime. Templates for EAGLE and KiCAD to create shields can be found here.[/feature][feature show_icon=”true” shape=”hex” title=”Bee Socket” icon=”signal”]Extend the wireless capabilities by using third-party modules compatible with the (X)Bee socket.[/feature]
[heading header_type=”h1″ header_size=”normal” header_weight=”regular” header_align=”left” header_underline=”bordered-header”]Hardware[/heading][feature show_icon=”true” shape=”hex” title=”Hardware Buttons” icon=”toggle-down”]3 on-board buttons with android- and reset-functionality[/feature][feature show_icon=”true” shape=”hex” title=”Dimensions” icon=”arrows”]PCB size: 165mm x 60mm[/feature][feature show_icon=”true” shape=”hex” title=”General Purpose LED” icon=”lightbulb-o”]On-board GPIO-LED controllable by code[/feature][feature show_icon=”true” shape=”hex” title=”Real Time Clock” icon=”clock-o”]Battery-backed RTC with coin cell holder[/feature]
[heading header_type=”h1″ header_size=”normal” header_weight=”regular” header_align=”left” header_underline=”bordered-header”]Software[/heading][feature show_icon=”true” shape=”hex” title=”Linux” icon=”linux”]Debian image will be available on launch[/feature][feature show_icon=”true” shape=”hex” title=”Android” icon=”android”]Android image will be available on launch[/feature][feature show_icon=”true” shape=”hex” title=”Python Bindings” icon=”code”]Python libraries to interact with most of the hardware features[/feature][feature show_icon=”true” shape=”hex” title=”Node.js Modules” icon=”code”]Node.js modules to interact with most of the hardware features[/feature][feature show_icon=”true” shape=”hex” title=”Node-RED Nodes” icon=”code”]Node-Red nodes to interact with most of the hardware features[/feature]

The Watermelon IoT Development Board is Open Source Hardware (OSHW). Its schematic and PCB layout are licensed under Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0). The CAD sources are available so you can study, modify, distribute, make and even sell derivatives of the Watermelon IoT Board. There’s no non-commercial restriction. The Watermelon IoT board itself is based on the OlinuXino Lime by Olimex.

Read more about our product philosophy

However, the trade mark “Watermelon IoT Board” and the silkscreen graphics remain intellectual property of Whitebox Labs and can’t be used in your derivatives.

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