The new Arduino Tian board is powered by Atmel’s SAMD21 MCU, featuring a 32-bit ARM Cortex® M0+ core and a Qualcomm Atheros AR9342, which is an highly integrated MIPS processor operating at up to 533MHz and feature-rich IEEE802.11n 2x2 2.4/5 GHz dual-band WiFi module. Qualcomm Atheros MIPS supports a Linux distribution, based on OpenWRT named Linino. The Arduino Tian has also a build in 4GB eMMC memory that will can be helpful to build your projects. It is possible to Switch ON/OFF the Linux port from the MCU to reduce the power consumption.
NB: In some countries, it is prohibited to sell WiFi enabled devices without government approval. While waiting for proper certification, some local distributors are disabling WiFi functionality. Check with your dealer before purchasing a Tian if you believe you may live in such a country.
NB.
Before to start to run Arduino Tian must install CP201x driver on the computer.
Drivers link: http://www.silabs.com/products/interface/Pages/CP2105EK.aspx
The Arduino Tian can be powered via the micro USB connection or with an external power supply. The power source is selected automatically.
External (non-USB) power can come either from an AC-to-DC adapter (wall-wart) or a battery inserted in the Gnd and Vin pin headers. The board will automatically detect which power sources are available and choose which one to use according to the following priority:
External power required is of 600mA and 5V.
The power pins are as follows:
The ATSAMD21G18 has 256 KB of flash program memory (with 69 KB used for the bootloader). The bootloader is factory pre burnt by Atmel and is stored in a dedicated ROM memory. The bootloader is protected using the NVM fuse. It also carries 32 KB of SRAM.
It is not possible to access the I/O pins of the Atheros AR9342. All I/O lines are tied to the Atmel SAMD21.
The Atheros is connected a usb hub with 4 ports (see the block diagram) to which are connected the Bluetooth, memory eMMCs, the SAMD21 and the USB Host port.
Each of the 20 digital i/o pins on the Tian can be used as an input or output, using pinMode(), digitalWrite(), and digitalRead() functions. They operate at 3.3 volts. Each pin can provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by default) of 20-50 kOhms.
In addition, some pins have specialized functions:
There are 3 reset buttons with different functions on the board: MCU-RST to reset SAMD21, LNX-RST to reboot AR9342 and WLAN RST to reset WiFi (7-10 seconds) and to reset default configuration (more 30 seconds).
The Arduino Tian has a number of facilities for communicating with a computer, with another Arduino or other microcontrollers, and with different devices like phones, tablets, cameras and so on. The SAMD21 provides one hardware UART and three hardware USARTs for 3.3V serial communication.
The Arduino software includes a serial monitor allowing simple textual data to be sent to and from the board. The RX and TX LEDs on the board will flash when data is being transmitted via the ATSAMD21G18 chip and USB connection to the computer (but not for serial communication on pins 0 and 1).
The USB port is connected to the CP2105. It allows for serial (CDC) communication over USB. This provides a serial connection to the Serial Monitor or other applications on your computer. When the board is connected to the computer appear 2 COM ports/ttyUSB, one is connected to the UART of SAMD21, while the other is connected to the serial port of the Linux processor.
The SAMD21 also supports TWI and SPI communication. The Arduino software includes a Wire library to simplify use of the TWI bus. For SPI communication, you can use the SPI library.
The Arduino Tian can be programmed with the Arduino software (download).
If you use Linux-based OS follow the guide Arduino IDE onLinux-basedOS.
Uploading sketches to the SAMD21 is different from how it works with the AVR microcontrollers found in other Arduino boards: the flash memory needs to be erased before being re-programmed. Upload operation is managed by a dedicated ROM area on the SAMD21.
USB port: To use this port, select "Arduino Tian as your board in the Arduino IDE. The USB port is connected to the CP2105. Installated the driver the user view two serial ports: one for SAMD21 and other for AR9342. Connect the Tian USB port (the one closest to the reset button) to your computer. Opening and closing the USB port at 1200bps triggers a 'soft reset' procedure:the board is restarted with the boot loader.
Note:
Keep in mind that every time you open the Serial Terminal then the Microcontroller is resetted.
Note:
At the moment the Bridge library isn't compatible but it is possible to use the Ciao library.
Rather than requiring a physical press of the reset button before an upload, the Tian is designed in a way that allows it to be reset by software running on a connected computer. The reset is triggered when the Tian's virtual (CDC) serial / COM port is opened at 1200 baud and then closed. When Initiation this happens, the processor will reset, breaking the USB connection to the computer (meaning that the virtual serial / COM port will disappear). After the processor resets, the bootloader starts, remaining active for about 8 seconds. The bootloader can also be initiated by pressing the MCU-RST button on the Tian. Note that when the board first powers up, it will jump straight to the user sketch, if present, rather than initiating the boot loader. Because of the way the Tian handles reset it's best to let the Arduino software try to initiate the reset before uploading, especially if you are in the habit of pressing the MCU-RSTbutton before uploading on other boards. If the software can't reset the board you can always start the bootloader by pressing the reset button on the board.
DSN files: arduino-tian-reference-design.zip
Schematic: arduino-tian-schematic.pdf