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INTRODUCTION |
The Teleo Analog In Module is a specialized module designed to provide a Teleo Network with twelve analog inputs. This module is especially useful when there are a large number of voltages to be read by a system. In addition to the twelve terminals provided for analog connections, there are three sets of power and ground terminals to assist powering and grounding sensors and also to provide +5V and Ground references for voltage dividers.
Since the inputs are analog, reading voltages from 0V to +5V, this device can also be used to interface digital signals - where a binary zero is read by the board as zero volts and a binary one as +5V.
If you only require four or fewer inputs, the Teleo Multi IO Module can be considered instead, since it offers many other kinds of inputs and outputs in addition.
To use the Analog In module, you'll need other Teleo Components. See the Teleo System overview in the Teleo System section of the Teleo User Guide. For information about setting up a Teleo System see the Teleo Hardware Setup section of the same guide.
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PACKAGE CONTENTS |
Teleo Analog In Module
A Teleo Analog In Module providing up to 12 analog inputs. Teleo Analog In Manual
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OPERATING INSTRUCTIONS |
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Teleo Analog In Module |
The Teleo Analog In module offers twelve different analog ins, designed for situations where a large number of analog ins is necessary and/or appropriate. The idea is that you can take various widely available electric devices, wire them into the Teleo Analog In and have them available for use inside Max and the Teleo Application SDK.
Each of the inputs on the Teleo Analog In is an independent device which has its own corresponding object . Analog In devices can be used to measure continuous quantities, like temperature, position, pressure, etc. In addition, the Analog In devices can read digital inputs - switches on or off, etc.
Analog In Module Concept Diagram Each of the inputs has its own screw connector so it can be connected to stripped wire. From the diagram below, and clockwise from the right, you can see that there are twelve Analog Inputs.
Analog In Module Connection 1 Also you will notice that there are three power connectors with 5V and ground (GND) positions. You'll learn how to use them in the next section.
For now it is important to remember a couple of basics:
- never connect the 5V supply directly to the ground (GND) this would cause a short circuit of the board's local power supply.
- while you're working with the board, it pays to monitor the temperature of the 5V regulator. If it is too hot to touch - disconnect the Teleo Analog In from the network and see what the fault might be.
- under extreme conditions, components can be so taxed that they can give off smoke with a very distinct "frying electronics" smell. Once a component does this, it is often destroyed, so this should be avoided if at all possible. If it does happen, unplug the Teleo Analog In board and check your circuit. The location of the smoking component will give a clue about what's going wrong.
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Analog In Device |
The twelve Analog In devices read voltages arriving at the connectors and convert them into a range that you can specify. The input is sensitive to a voltage range of 0V through to 5V. Although the input is protected, you should never try to apply a voltage outside this range to it. Once the voltage is read, the software on the Teleo Analog In module converts the number obtained into a range that you can specify. See the Analog In overview in the Modules Section of the Teleo User Guide.
The default range is -100.0 to 100.0, meaning that if there is nothing connected to the device or if it is reading 0V, the device will report back -100.00 or a number very close to it. With the same range specified, 5V applied to the connector will result in a number of around 100.0 being reported back.
Also by default, the measurement is read every 100ms - or ten times a second. This can be changed to 10ms or up to 10000ms (once every 10seconds). Alternatively, the device can be put into a mode where it only reads when it is asked to.
The Resolution of the device can also be modified. Its value is represented in bits. Minimum 1, Maximum 10. 1bit will result in only two levels between the specified minimum and maximum, while 5bits will yield 32 levels and 10bits will yield 1024 different levels.
With the large number of inputs available on this module, it is very easy to overwhelm the Teleo Network with data. Sample Period and Resolution can be manipulated to great effect here. Clearly if the sample period is increased (meaning longer time between successive samples) the data rates are reduced. Also if resolution is reduced there will likely be fewer changes in the value and thus less data. For only a few inputs you can run the devices at top speed (10ms sample period) and highest resolution (10bits), but as you add inputs you may find you need to either slow the sampling down a bit or reduce the resolution.
In general you should only use the resolution and sampling period you really need. If you're measuring temperature, for example, you might need 10bits of resolution, but you might need to sample the sensor only once a second or so. If you're reading levels of light in a quickly moving situation, you might chose to have very fast updates, but use only very low resolution.
Programming - Max
The Max component that corresponds to Analog In devices is called t.ain. The name specifies the product (t for Teleo), the module and the device (ain for Analog In).
See the t.ain documentation page for more details.
t.ain
Connecting the Analog Input
The most basic interesting device to connect to the Analog In device is a potentiometer. Potentiometers are often used as volume controls in sound devices. The potentiometer is made around a strip of resistive material. This strip is connected to voltages on either end and has a wiper which can connect to the material at any position along its length. The wiper reads values that are proportional to its position along the strip. For example, when one end is connected to 5 volts and the other end to 0 volts (ground), the wiper will register voltages of just below 5 volts when it is positioned just beside the 5 volt end, 2.5 volts when half way along, and almost 0 volts when near the 0 volt end. In electronics, this is called a voltage divider, since the way it is constructed the upper and lower voltages are divided in two parts. For more information about this see Voltage Divider in the Introduction to Electronics section of the User Guide.
When the Analog In is set up like the photo below and connected to a Teleo Network it will report the range of values as the potentiometer is turned.
Analog In Module + Potentiometer Analog In Module + Potentiometer Sample Circuit
The next-most basic sensor is the light sensor. This is like the potentiometer in that there are resistive elements connected to 5 volts and ground and a tap (like the potentiometer's wiper) in the middle. The difference is that where the voltage change with the potentiometer is caused by moving the wiper across the resistive strip, in this example the voltage is changed because the resistance of one of the elements changes.
Looking at the diagram, you can see that the light sensor connected from the 5 volt line to the Ain line and the resistor connecting the Ain line to the Gnd connector. If the resistance of the fixed resistor and the light sensor are equal the Ain line would register 2.5 volts, since the Ain would be sitting "halfway" between 5 volts and 0 volts.
Now, when the light sensor it is exposed to light it offers less resistance so the Ain point ends up being "closer" to 5 volts and the voltage read at the Ain connector would rise above 2.5V
Analog In Module + Light Sensor Analog In Module Analog In
+ Light Sensor Sample Circuit
The Analog In device need not be connected to simple voltage dividers. It can be connected to anything that provides a 0V - 5V output. The list of these devices is long: temperature sensors, acceleration sensors, pressure sensors and so on.
Analog In
+ Generic Sensor Sample CircuitInterfacing a switch or push button to the Analog In module involves connecting the switch to ground or +5V then using a pull-down or pull-up resistor to make sure that when the contact is open there is a connection through a resistor to the opposite rail.
You must be careful with the analog inputs to keep the voltage within the limits of 0 to 5 volts. All the inputs are protected against this, but accidents can happen. Be careful!
TROUBLESHOOTING
COMING SOON!
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