Many users of the tiny, inexpensive, Linux-based single board computer, the Raspberry Pi or RBPi, would like to connect it to the outside world, but do not know how. According to Maker Jonathan Peace, ArdHat is most suitable for connecting the barebones Unix platform to the real world. Therefore, he calls it the “missing link that connects the Raspberry Pi with the real world.”
Onboard the ArdHat is an Arduino-compatible embedded MCU, the ATmega328P. Its specialty is very quick response to all real-time events, allowing the RBPi to take care of the rest of the heavy lifting. HATs or Hardware Attached on Tops are most suitable for the RBPi Model B+. These HATs conform to specified standards and make life easier for users. One significant feature of HATs is an onboard system to allow the RBPi B+ identify the connected HAT and automatically configure its GPIOs and drivers for the plugged-in board.
Real-world systems need low-power operation, real-time performance and environmental protection and awareness, all of which the ArdHat provides. As a super-compact RBPi compatible HAT, the ArdHat enhances and protects the RBPi for applications in the real world, while being accessible to everyone possessing an Arduino.
You can have the ArdHat in four different models – two with long-range radio modules and the other two without the radio. All four are packed with analog sensors, user interface controls, a real-time clock, 5V Arduino shield capability, supply monitoring, a wide operating range of voltages that includes automotive, full power/sleep management and high current outputs for driving peripherals. All these are accessible from the AVR chip on-board the ArdHat or the RBPi.
Those looking for more power can also choose between the ArdHat-W and the ArdHat-I. The first has a 15Km long-range ISM wireless node, while the latter has a 10-DOF inertial measurement unit. Both make the boards ready for IoT right out of the box.
Apart from a flat top design that allows plenty of space for placing a battery or a prototyping board, the ArdHats accept several Arduino shields. Users can also buy an optional high-capacity 1800mAh battery, especially tailored to plug-in directly into the JST standard connector. The whole arrangement fits snugly between the shield headers of the board’s flat top design.
Among the smart power management feature of the ArdHat is a power switch and charge control. That allows the RBPi to run on several types of power supplies, including LiPo batteries to automotive supplies. Therefore, the HAT can simply connect to systems operating on 5V and drive them – smart LEDs, quadcopters and servos.
Other than protecting the RBPi from external power outages and voltage spikes, the TopHat enclosure offers a physical safeguard as well. Made of laser-cut Perspex, the enclosure allows access to pins of the Arduino shield for teaching and experimental purposes. At the same time, the enclosure protects the delicate circuitry of the RBPi circuit board.
The scheduler and applications for the ArdHat are entirely open-source. Using the Arduino IDE, users can modify and update even the preloaded sketch of the real-time software on the ArdHat.