Tah - Lego block for Internet of Things

TAH Main Board

In this blog post I am going to introduce the Tah platform and talk about some of the applications using it.

Tah is a hardware as well as a software platform.  The hardware has following characteristics

1. An Arduino with Bluetooth Low Energy (BLE)
2. Onboard USB (HID device) - emulating a keyboard and a mouse
3. Great building block (like a LEGO) for your home automation systems using Arduino.

USB HID-Compatible

ATmega32u4 — the microcontroller at the heart of Tah — has onboard USB 2.0 support, that is used to directly program the Tah without having to use a USB-to-Serial converter. Tah can also act as a USB human interface device (HID), which enables you to create your own keyboard, mouse, joystick, or other input devices, all without the need for installing special software on the host computer. If you want to create a new smarter custom keyboard that communicates with your smartphone, you need not look beyond the Tah. It already has sample applications that allow you to control your PC, Mac, Linux, PlayStation and Xbox without ever needing to write any code for those platforms — all you need to do is program your Tah board and make a smartphone app, for which we’ve also provided open source examples for both iOS and Android to get you started.

Bluetooth Beacon

Each Tah board can serve as a Bluetooth beacon which tells your smartphone where exactly it is located based on the beacon’s unique identifier. This is amazing for indoor navigation, contextual notifications, and microlocalization.

Here are some of the interesting applications that can be built using the Tah and its shields.

Infrared Control (IR Transceiver Shield)

IR has been used for near range wireless communication for a long time. We have TVs, music systems, air conditioners and so many other things that have their own remote control  

We have created an IR shield which has a transmitter as well as a receiver on board. With this connected to your Tah, you have a universal remote that can be controlled from your smartphone. Forget keeping a bunch of remotes to control everything in your living room. You could do all of that from a single app on your phone. 

Relays (Relays + Sensors Shield)

Electronics is usually associated with low voltage DC appliances but so much of what we use everyday runs on 110V/220V AC. All our light bulbs, fans and everything else.  

To control these there is a Relay shield that translates signals between DC and AC so to speak. One can use the GPIO pins 2 and 3 from the Tah to control 2 relays. 

Bridge the gap between electronics and electrical with this relay plus sensor shield. It comes with its own app which you can use with some standard sensors such as the depth and temperature sensors among others.

• Input working voltage: 7V to 12V DC
• Two Relays rated 5V DC.
• Load Capacity: 10A/120VAC, 10A/24VDC, 7A/250VAC
• Relays are connected to Pin number 2 and 3 of Tah
• Digital Pin Numbers 4 to 13 & Analog Pin Numbers A0 to A5 all are connected to 3 pin standard Grove connector

Arduino

That's why we have the Shield Shield which consists of the Arduino UNO R3 layout which let's you use the already available shields in their projects. This shield makes Tah compatible with all existing Arduino Shields, It means all your Arduino-compatible shields are also compatible with the Tah. (Input working voltage: 7V to 12V DC)

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By no means is the above list comprehensive. There are many more amazing things that can be built using the Tah.  

Examples on the website. A forum to discuss more about this.

If you would like this device, you can grab them here.

(This is a product of Reavealing Hour Creations who run this blog and the IOT Community)

Arduino based Light Following Rover

Ah, what a fun!!! :) Today we built the “Light following rover” a variant of what +Unmesh suggested in one thread on Internet of Things Pune group discussion.

We bang-on-started (Thanks to Dhiraj) with first understanding basic circuitry and designed a simple circuit to check the light signals in six directions i.e. Three in-front and Three in-back. i.e. left, center, right in clock wise direction on Front and Back side of the rover. Based on this understanding we proceed to build the rover. Our requirement was simple "The bot should move to direction where there is maximum light among all the directions".

Then second thing was to calibrate the LDRs so as to understand the variations in light (high, low and normal values), also normalize the values of LDRs as each might give different values for same amount of light. We checked each LDR ad-hoc way, normalized the values in program directly.

Now, the big problem was, we need to control/drive Geared DC motor(s) using our Induino board. As you know, It’s difficult to control the motors directly (motors require more current and voltage than the typical output values and we needed special circuit for the same).So, we needed some Motor driver circuit. Thankfully Dhiraj has already built an Arduino shield "2-Channel Actuator Controller" which is capable of controlling upto 4 DC motors. Here, We have used the same Actuator controller shield to drive the motors of the rover. So, using this shield, We are actually controlling two motors via a single actuator channel.   You can also build ckt using L293D/ L298 or buy a circuit to control the motors popularly known as HBridge/ DC motor controller.

Now, we needed the power source and few 1K resistors to build the sensor circuit. Sensor ckt is very simple as shown in the diagram below.  Each LDR’s signal will be inputted to Induino on Pins A0 to A5. Also motors are controlled via Digital Pins in Output mode 2, 3, 4, 5, These are directly interfaced via the actuator shield.

As mentioned, Motors on each side of the chassis are shorted together. That means motor connected on Left side of chassis are shorted and connected to one output socket of ‘Actuator controller shield’ while other side to other socket.  This Shield has 4 relays, 2 relays are used to control single socket’s current direction. Make sure all the motors move in one direction before screwing. J

Sketch below is loaded and Fun begins… Here we are controlling the forward motors with Pins 2, 4, so code is written in such way. Your pins might differ so do take care of those.

We are looking forward to add collision detection soon....so stay tuned!!!