Sigalabs, a communication and data logging solutions supporting open platforms like Arduino based in Athens, Greece has introduced a new tool for the first open source wireless sensor networks (WSN) called ‘The WiStick’.
The WiStick is a microcontroller board based on ATMEGA32u4, that runs at 3.3V and 8MHz, with 14 digital input/output pins, 6 analog inputs, a hardware serial port (UART), a USB interface; working independent from the serial port, which was created to take care of the programming and debugging issues, mounting holes for pin headers and screws. The tool will also come with Li-Po JST 2-pin battery connector that you can use to power the board and a very sophisticated charging IC with auto power source selector.
According to Kostas, one of the main figures of Sigalabs, “the Wistick can be loaded with Arduino bootloader and give you the same mechanism to operate. This is a new generation of charging IC’s that is a great choice if you want the battery to work as a backup power source to your system. Let’s say you have an external voltage connected to the board, the charger will disconnect the battery from the main system and charge it”.
Sigalabs is also involved in Advanced GPRS Shield, Vehicle OBD2 Shield and GM862 Evaluation board
One of the advantages of Wistick is that it allows the board to be powered from the external power source without wasting the battery’s energy and life; maintaining that no charging cycles are wasted. There is a stability of power from the battery and the external source, easily moving from one form to the other; in order to keep the board up and running all the time and extend the battery life and charging cycles to the maximum.
In order to maintain a minimum cost and maximum functionality, the innovators chose the most popular, available, low cost and trusty RF module existing today. This is the Nordic nRF24L01+
“A highly integrated, ultra low power (ULP) 2Mbps RF transceiver IC for the 2.4GHz ISM (Industrial, Scientific and Medical) band. With peak RX/TX currents lower than 14mA, a sub μA power down mode, advanced power management, and a 1.9 to 3.6V supply range, the nRF24L01+ provides a true ULP solution enabling months to years of battery life from coin cell or AA/AAA batteries.
Now you may ask, why it is not integrated on the board but we are using a nasty header instead?
Kostas explains that the cost of a small RF module based on nRF24L01+ shipped from China is unbeatable! The Mouser, a major distributor in EU, have these for 3 euros each, without calculating the cost for RF antenna and RF optimization.
Secondly, we want to make this board as modular as possible, so if in the future there is a better RF module or if you want to choose between a low cost PCB antenna module or a long-range high power with external SMA connector, you can have this extensibility easily.
According to Sigalabs, the availability of Wistick will be in a matter of days for the first PCB’s to arrive, and if all goes well they will start producing the first batch and at the same time developing the open source firmware.
According to Kostas, “stay tuned, we’ve got more fascinating things coming soon”
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