The 3DoT Board designed by Humans for Robots is now available to purchase from the Crowd Supply website offering an easy platform to build your perfect robot. Prices start from $49 and orders placed now will be start shipping during November 2020, free shipping is available throughout the United States and worldwide shipping is available for $10 extra.
Features of the 3DoT Board :
– Open source hardware
– On-board battery with automatic USB battery charging
– Connector for additional battery
– Reverse polarity protection
– Open source iOS/Android app
– Arduino library support
Specifications of the 3DoT Board :
– ATmega32U4 microcontroller
– RCR123A 650 mAh battery with protection circuit.
– FCC-certified BLE 5.0 Bluetooth module
– Dual motor driver with regulated 500 mA current limit per motor
– Standard 2.0 mm JST connectors for up to 2 DC motors
– Standard male header pins for up to 2 servos
– Female 8-pin forward sensor header: 4 analog pins, 3.3 V, GND, and I²C
– Female 16-pin top shield header with digital, analog, I²C, SPI, 3.3 V, and 5 V pins
– 3-position switch (OFF/PROGRAM/RUN) for reliable and easy programming
“The board’s microcontroller and other components will only draw a couple of mA. All the battery’s power is going to be consumed by the motors. At typical operation, small motors such as the ones included in the accessories kit option here on Crowd Supply only draw around 100 mA, and their stall current (current drawn at maximum load) is around 400 mA. So with two of these motors, we will draw 800 mA at most and we should be fine, right? Unfortunately, no.
When starting a motor, there is an “inrush current” often much higher than the rated stall current. Without the right precautions, this instantaneous current draw from multiple motors will cause a drop in the battery’s voltage, which then causes other components on the board such as the microcontroller to shut off or malfunction.
The single-cell LiPo battery used on the 3DoT, chosen for its ideal form factor, is rated at 600 mAh and 2 C. This means it supposedly can deliver 600 mA for one hour, and its maximum rated current is 600 x 2 = 1.2 A.