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PRODUCTS DOCUMENTATION	Teleo Multi IO User Guide Documentation for the Teleo Multi IO Module:   TABLE OF CONTENTS: Introduction Package Contents Operating Instructions Teleo Multi IO Module Analog In Device Digital In Device Digital Out Device PWM Device Troubleshooting Technical Specifications

The Teleo Multi IO Module is a multi-purpose module designed to provide a Teleo Network with analog inputs, digital inputs, digital outputs and pwm outputs.

To use the Multi IO 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.

 

 

Teleo Multi IO Module	A TeleoMulti IO Module providing 4 digital inputs, 4 digital outputs, 4 analog inputs, and 2 PWM outputs.
Teleo Multi IO Manual

 

 

Teleo Multi IO Module
Analog In
Digital In
Digital Out
PWM

The Teleo Multi IO module offers four different kinds of inputs and outputs - ideal for experimenting. The idea is that you can take various widely available electric and electronic devices, wire them into the Teleo Multi IO and have them available for use inside Max and other programming environments.

Each of the inputs and outputs on the Teleo Multi IO 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. Digital Ins can convey whether something (e.g. a limit switch or a push button) is on or off. Digital Out devices can switch something (e.g. motors, valves or lights) on or off. PWM devices can switch something on and off thousands of times a second giving the effect of a variable level of activation - like a dimmer switch for a light or a speed controller for a motor.

Multi IO Module Concept Diagram

Each of the inputs and outputs 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 four Analog Inputs, four Digital Inputs, four Digital outpts and two PWM's.

Multi IO Module Connection 1

Also you will notice that there are power connectors with V+ (this is the voltage your power supply provides), 5V and ground (GND) positions. You'll learn how to use them in the next section.

Note that more recent boards have two adjacent GND connectors, rather than the one shown in these pictures.

For now it is important to remember a couple of basics:

• never connect the V+ connector to the 5V connector - this would put the whole power supply at V+ onto the board's electronics which are designed to run at 5V. Although this situation is guarded against - this may still destroy components on the board.
• never connect the V+ or the 5V supplies directly to the ground (GND) this would cause a short circuit either of the whole power supply or the board's local power supply.
• while you're working with the board, it pays to monitor the temperature of the 5V regulator, the FET switches and the fuse. If any of them are too hot to touch - disconnect the Teleo Multi IO 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 Multi IO board and check your circuit. The location of the smoking component will give a clue about what's going wrong.

The four 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 Multi IO 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.

As an additional feature, the rate of change of the value is provided. This means that if, for example, the voltage on the connector was changing by a ranged amount of 10 units between every sample, this value is available to be read too.

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 inputs available on this module, it is possible to overwhelm the Teleo Network with data. Sample Rate and Resolution can be manipulated to great effect here. Clearly if the sample rate 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 rate 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.

Finally, from within the range of values being produced a sub-range can be identified. When the value being read from the connector is within the specified subrange, a flag is set. This flag is available to Max and can be used to switch something else on and off.

Multi IO Module Analog In

 

Programming - Max

The Max component that corresponds to each Analog In device is called t.mio.ain. The name specifies the product (t for Teleo), the module (mio for Multi IO) and the device (ain for Analog In).

See the t.mio.ain documentation page for more details.

t.mio.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.

When the Multi IO is set up like the photo beneath and connected to a Teleo Network it will report the range of values as the potentiometer is turned.

Multi IO Module Analog In + 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

Multi IO Module + Light Sensor	Multi IO 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.

Multi IO Module Analog In + Generic Sensor Sample Circuit

You must be careful with the analog inputs to keep the voltage within the limits of 0 to 5 volts. All the Multi IO inputs are protected against this and we try to make it hard to make a mistake by only providing connectors for these voltages on the Analog In side of the board, but, accidents can happen. Be careful!

The four Digital In devices read the voltage at their connectors. If the voltage is above about 2 volts they read as 1 or true, if below 2 volts they read 0 or false. They have a slight bias to reading on, so you can make them read off by connecting the line to ground. See the Digital In overview in the System Section of the Teleo User Guide.

The input can be inverted - and in fact it is by default, since connecting the Digital In via a switch to ground is so convenient, and people want the "on" state to be when the button is pressed.

Like with the Analog Input, the period of time that the Multi IO processor waits between checking the Digital In inputs is 100ms by default, but can be changed to much more frequently (10ms) and much less frequently (>10000ms).

Multi IO Module Digital In

Programming - Max

In Max, the Digital In object is fairly simple. It is called t.mio.din, "din" being the abbreviation for Digital In.

See the t.mio.din documentation page for more details.

t.mio.din

Connecting the Digital In

The simplest circuit to connect to the Digital In board is a push-button. It works because the Digital In wires are internally biased to 5V by weak pull-up resistors. This means that left alone, they'll register 5 volts at their inputs which will equate to a digital "true" or "on". When the push button is activated, it connects the input to ground (0v). This new connection to ground is of such a lower resistance than the internal pull-up resistor that the voltage on the Digital In connector becomes very close to 0 volts. When the push button is released, there is no strong pull to ground through the switch so the connector is pulled back up to 5 volts.

So when the button is pressed the value read is a logical 0, and when it is released it's a logical 1. Since people usually think of a push button as being on when it's connected and since configuration is so convenient, the output of this device is usually inverted. When inverted, pressing the button causes a one to be sent, releasing it causes it to return to zero.

Multi IO Module Digital In + Push Button	Multi IO Module Digital In + Push Button Sample Circuit

 

And like the Analog In, the Digital In can be connected to any source of logical signals. Also like the Analog In devices, care should be taken to avoid connecting anything outside the range of 0 to 5 volts.

Multi IO Module Digital In + Generic Sensor Sample Circuit

There are four Digital Out circuits. They are the most simple devices on the Multi IO object since they are either on or off. It's that simple. See the Digital Out overview in the System Section of the Teleo User Guide.

Digital Out circuits can be used to switch devices like motors, relays, values and lights on and off that draw up to 1A of current. The Digital Out circuits can also be used to generate logic signals for controlling other devices.

The Digital Out circuits operate by making a clear channel to ground for whatever voltage is applied to their connectors. This switching is done by a FET (field effect transistors) in the small 4 legged rectangular chips next to the outputs. These FET switches can handle moderate currents - but nothing too big. Small motors, relays, solenoids, lights and valves should all be OK. Larger devices might not work well. Where possible, before using some new item, try to understand what its current requirements are and ensure they draw less than one amp.

You will notice that there are both 5V and V+ connectors available for connecting to the Digital Out connectors. You can use either, but not both on the same connector since that would result in a direct connection between the V+ supply and the 5V supply. The V+ will supply up to a total of 6 amps to all output circuits on the board. The 5V supply is very limited. do not try to run motors, and other mechanical devices off this supply since it will almost certainly cause the 5V voltage regulator to overheat and or the processor to reboot. The 5V supply is provided to control LED's and other very frugal users of current.

Multi IO Module Digital Out

Programming - Max

The Max Digital Out object (called t.mio.dout) is very simple. Just send it a "1" to turn the device on or a "0" to turn it off.

See the t.mio.dout documentation page for more details.

Max Component: TeleoMulti IODout

Connecting the Digital Out

Circuits that are controlled by Digital Out signals can be very simple. Connect a power source on one side and the Digital Out signal on the other.

One of the simplest circuits uses a normal incandescent light bulb. What's important is that the voltages and currents are within the correct range. When you select the V+ line to supply the power to the light, make sure that the bulb can handle the voltage! Similarly check to make sure that the current rating for the bulb is less than one amp. Most small incandescent bulbs will fall within this range, but larger halogens do not. As usual, check the connections carefully before turning the power on and watch for signs of overheating on the appropriate FET device.

Multi IO Module Digital Out + Incandescent Light Bulb	Multi IO Module Digital Out + Incandescent Light Bulb Sample Circuit

Another very common type of device to control is solenoids. They can be hooked up to act as actuators or to valves that control the flow of liquids (hydraulics) and gases (pneumatics). The circuit is virtually the same as the circuit for the lamp above. The basic cautions to observer are similar to the ones for the light example above: check to make sure that the rated voltage for the solenoid matches your power supply. Valves (and other solenoids) often specify a duty cycle. If the duty cycle is "Continuous" this means that it can be left on indefinitely. If the duty cycle is "Intermittent", then it's designed to be run only for short periods which are sometimes specified (i.e. 50%, etc.) If an Intermittent solenoid is run continuously, it may overheat and in extreme circumstances may be destroyed.

Multi IO Module Digital Out + Solenoid

Multi IO Module Digital Out + Valve Sample Circuit

Finally, there's nothing to prevent the Digital Out signals from controlling other digital things. What is required is a pull up resistor. When the Digital Out switch is off, the resistor makes the connected circuit see approximately 5v. When the Digital Out switch is on the connected circuit is directly connected to ground (by the Digital Out's FET) and it sees 0V. Note that in this configuration the output is inverted. When the Digital Out device is sent a "1", the FET switch closes and connects the external logic to ground - which it interprets as a "0" or off. When the Digital Out device is sent a "0", the FET switch deactivates, the external resistor pulls the line up to 5V, and the external logic sees a "1".

Multi IO Module Digital Out + Misc. Logic Sample Circuit

There are two PWM devices on the Multi IO board. PWM's can be used to control the speed of motors, brightness of lamps, etc. See the PWM explanation in the Introduction to Electronics section of the Teleo User Guide for more information.

Electronically, the PWM devices are identical to the Digital Out devices. One amp switches complete circuits connected to them by controlling the connection to ground. Again, the current capacity of the FET switches is limited: be careful what you connect. Watch for overheating and smoking! Never connect the V+ connection directly to the PWM output since as soon as the switch turns on, the current will surge from the power supply, through the switch, possibly destroying it. See the Digital Out / PWM overview in the System Section of the Teleo User Guide.

Multi IO Module PWM

Programming - Max

The Max object corresponding to the PWM device is quite simple. Sending a value to the leftmost port sets the PWM Duty Cycle.

See the t.mio.pwm documentation page for more details.

t.mio.pwm

Connecting to the PWM

In general, the same kinds of circuits can be used with the PWM devices as with the Digital Output. Here is an example of a motor which has been checked to draw less than 1 amp when unloaded. One side of the motor goes to the V+ line and the other goes to the PWM connector. Note that this motor will only turn in one direction as shown here, since there is no way to get the current flowing in the opposite direction. For that you need an H-Bridge, or a relay setup that can reverse the voltage to the motor.

Multi IO Module PWM + DC Motor

Multi IO Module PWM + DC Motor Sample Circuit

POTENTIAL PROBLEMS:

• digital inputs don't seem to work
• digital outputs don't seem to work

First Step:
See if your problem is described in the list above. If so, click on the link to see if the suggestion solves your problem.

Second Step:
Check the known problems section of the MakingThings website - in particular the System Troubleshooting and Max Troubleshooting sections.

Third Step:
Post the problem to the MakingThings discussion list. This list is checked regularly by the MakingThings staff. In addition, if another Teleo user has experienced, and solved, this problem, you will have the benefit of their experience.

Fourth Step:
Email support@makingthings.com. We endeavor to reply to all problems within one day.

Quick Note: how to use Max and Teleo effectively:

• always exit Max before unplugging the USB cable
• always exit Max before removing power from the Intro Module (these two steps avoid the USB driver from hanging)
• if any object requires a specific address, then all objects should i.e. the optional address can be left off only when there is only one of each type of module i.e. the module type and device number completely identify every device on the network. as soon as there is more than one type of any module, then each and every object must specify both the device and address.
  

Affected Devices: Digital Inputs

Check:

• Are you connecting the circuit correctly? The digital in terminals need to be connected to Ground rather than +5V.
  
  

Affected Devices: Digital Outputs, PWM

Check:

• Are you connecting the circuit correctly? The digital out and PWM terminals need to be connected to V+ or +5V rather than Ground.