Welcome to the Miniguide. Before reading other sections of these instructions and before using the Miniguide, please read this important warning.WARNING: The Miniguide is designed to provide information to a blind traveller which will supplement that provided by other aids, such as the long cane or dog guide. It is stressed that it is not designed as a blind person's sole aid. Only use the Miniguide in a safe and familiar environment. Please note that drop-offs such as kerbs, edges of railway stations etc cannot be detected. Some objects may not be recognized in some circumstances (due to reflection or absorption of the ultrasonic beam). For example, smooth surfaces at an angle are often difficult to detect. Soft furnishings (or similar) can also be difficult to detect in some circumstances. If you have any doubts about your ability to use this aid, please seek assistance from an organisation with experience in mobility training.
The following instructions assume you are using a new aid that has not had its settings changed. If your aid is not new and there is the possibility the settings have been changed, then first go to the section regarding battery replacement - so that the aid can be returned to its original factory defaults.
The Miniguide is 55mm long, 35mm wide and 16mm thick. The two sensors, which send and receive signals from the aid, are at the front. They are small, metal cylinders with a mesh material at the front. The aid, apart from the sensors, is covered by a snug fitting bag. It is held in place by a strap which is fixed to the bag on one side and which passes between the sensors and is secured by Velcro on the other side of the aid. (Please note that the strap must not obscure the front of the sensors, ie. the strap must sit entirely within the gap between the sensors. Care must be taken when closing the bag, that the strap is positioned correctly.) A wrist strap is attached to the bag at the back of the aid. The earphone socket is at the back of the aid and is accessed through a small hole in the bag.
If the aid is lying on a table, then the ON/OFF button is on the side of the aid - about 1cm behind one of the sensors. The button can be felt as a bump under the bag material, pointing out sideways from the aid. Pressing the button should result in a short, high pitched "beep" being heard (make sure you release the button once you hear the beep). This indicates that the aid has been switched ON. You will probably now also hear the feedback tone, try waving your hand in front of the aid to make the feedback tone change. Pressing the button again should result in a low pitched beep being heard. This indicates that the aid has been switched OFF. Waving your hand in front of the aid now should not produce the feedback tone. Practise switching the aid ON and OFF to familiarise yourself with the ON/OFF beeps.
Switch the aid ON. Now place your hand about 5cm away from the front of the aid. The aid should be producing a very high pitched tone. Move your hand further away from the aid (keeping your hand in front of the aid). The pitch of the tone should lower as the hand is moved away. Try moving your hand at different speeds, to get used to how the aid reacts. Try pointing the aid at an uncluttered wall (or ceiling) and moving the aid forwards and backwards. The pitch should raise and lower as the distance changes.
Now point the aid in all different directions. If you are in a small room, the feedback tone will most likely always be heard. If you're in a large room, or outside, then pointing the aid in certain directions will cause the feedback sound to stop. The feedback tone stops when the aid can not detect an object within its current range (the current range should be 4 metres).
Please note that the aid automatically switches itself off after about one hours continuous use. So it is recommended that you switch the aid off occasionally, for example every 20 to 30 minutes. This will avoid the aid automatically switching off while it is in use.
NOTE: for the beginner, do not select any modes beyond Mode 7.
When learning how to use the aid, it is often less confusing to practice with a mode that has a shorter range eg. the 1 metre or half metre ranges. These shorter ranges mean that the aid will be silent most of the time, except when there is an object close to the user.
Modes are changed by holding the button down continuously for two seconds or longer. Releasing the button after a certain number of beeps selects the mode. Once a new mode is selected the aid will use that mode whenever it is switched on.
To select a mode, first make sure the aid is off. Now switch the aid ON, but DO NOT RELEASE THE BUTTON. You should hear the high pitch ON-beep as usual. About two seconds after the ON-beep you should hear another beep. While you continue to keep the button pressed, you will now hear a beep every second.
To select a mode, you count the number of beeps after the ON-beep. For example, to select mode 4, count 4 beeps after the ON-beep, then release the button.
Here is a step-by-step description on how to select Mode 4 (ie. the half metre mode):
Use your hand in front of the aid to confirm that Mode 4 is really selected. You should be able to hear the feedback tone stop around the half metre distance. If you misjudge the number of beeps, then just release the button and go through the above steps again.
The battery used in the aid is a CR2032 lithium battery. This type of battery is often called a "coin cell" because it is shaped like a coin. The battery holder is in the middle of the aid. After removing the bag cover, you should be able to feel the smooth coin shaped battery being held in place by some bumps. At one end of the battery holder there are three bumps and at the opposite end there are two smaller bumps. The battery can be removed by getting a fingernail under a battery edge and just "flicking" it up and out. Using two fingers either side of the battery makes battery removal even easier. If you don't want to use your fingernails, make sure whatever you do use to flick the battery out is non-metallic, and use only gentle force.
Before installing a battery, make sure the battery is the right way up. The battery has a groove on one edge, this groove must be on the underside of the battery as you install it - otherwise the Miniguide will not work. Installing the battery involves sliding the battery under the three bumps of the battery holder (as far as it will go) and then gently pressing on the other end of the battery until it clicks into place.
When a battery is installed, you may hear the aid "pipping" (ie. rapid beeping) for about twenty seconds. This pipping indicates that the aid has been reset and that all settings have been returned to the original factory defaults. If this pipping is heard at any other time, it may indicate that the battery needs replacing or that there is a dirty battery connection.
If the aid starts to lose sensitivity, especially in the longer ranges, then try installing a new battery. Discard the old battery if the sensitivity improves noticeably with the new battery.
If you want your current settings to be saved while changing the battery you should do the following:
If you want to return your aid to its original factory default settings you should do the following:
Earphones use slightly more power than the small speaker on the aid, so battery life will be shortened slightly when using earphones.
The earphones supplied with the aid have an inbuilt volume control and a mono/stereo switch. The volume control and switch are located on a small module, about half way along the earphone cable. The volume control wheel is at the top of the module (ie. the end closer to the ear pieces), since this wheel only protrudes slightly it can be a bit hard to find at first. If the switch is in the mono position, you will hear sound from both the left and the right earpieces. If the switch is in the stereo position, you will only hear sound out of the left earpiece (the sound will also be slightly louder). Note that most stereo earphones will only have sound coming out of the left earpiece (when used with the Miniguide).
Because the speaker in the Miniguide is tiny, it will be necessary to use earphones in all but very quiet locations. It is important to adjust the volume on the earphones to suit the situation. That is, volume should be increased in noisy areas and reduced in quieter situations. It is entirely the user's preference whether to use one or both earphones.
On the module containing the volume control, there is a small clip. It is very helpful, both for comfort and convenience, to attach this to a shirt pocket or another item of clothing close to the shoulder.
If earphones other than those supplied are preferred, it is important that they either have a volume control or that a separate volume control unit is used in conjunction with them. Note that some volume control units do not quieten the sound sufficiently for use with the Miniguide, so check before buying. It is also important that the earphones have a high sensitivity to ensure adequate volume. A sensitivity of 105dB or greater should be acceptable. Again, if possible, try the earphones with the Miniguide before buying the earphones.
Note that the aid can be silenced quickly by covering a sensor completely with your finger.
Certain things in the environment will cause interference to the Miniguide. The Miniguide detects objects by sending out an ultrasonic pulse and then listening for the echo. If something in the area is also producing ultrasonic pulses then the aid may indicate there is an object within range when really there is no object. Air brakes on trucks and sometimes car brakes will produce ultrasonic interference. The interference is usually occasional and short lived. For example the interference may sound as if someone quickly waved their hand in front of the aid.
If two Miniguides are used within close proximity of each other, they will interfere with each other. Unfortunately there is no way of avoiding this problem. The aid will still be usable, but the user must be careful to determine what is interference and what are real objects.
The modes with shorter ranges are more immune to interference than the longer ranges. So if interference becomes persistent in a certain area, switching to the 1.0 metre or the half metre range will help reduce the problem.
The sensor closest to the ON/OFF button is the sensor that sends out the ultrasonic pulses. If you cover this sensor completely with your finger, the Miniguide should be silent. If the Miniguide continues to make sounds with this sensor covered, then you know you have an interference source nearby.
Avoid dropping or knocking the Miniguide. The ultrasonic sensors could be permanently damaged by a severe blow.
The ultrasonic sensors are covered by a very fine mesh. Dirt and other substances can clog this mesh. If this mesh becomes clogged then the sensitivity of the Miniguide will be reduced, or the aid will stop working completely. Store the aid in a clean location, and avoid using the aid in dusty or dirty conditions. Store the aid with the sensors pointing down to help prevent dust and dirt entering the sensors.
The Miniguide is not water proof. It should certainly not be immersed in water - or any other type of liquid. If possible, it should not be exposed to heavy rain. If you are caught in rain without an umbrella, aiming the aid downwards will help to protect the sensors from the rain. If the aid does get wet and, especially if it stops working, it is important to dry it as soon as possible. Begin by wiping away any surface water. Keep the ultrasonic sensors pointing downwards, so that any water in the sensors will hopefully drain out. If the aid does not work, place it in a warm, dry place - with the sensors pointing down. A hair drier may be used to provide warm air, but be careful not to hold it too close to the Miniguide as excessive heat could cause damage.
When using the Miniguide held in a hand, it is a good idea to put the cord attached to it over your wrist. If you want to let go of the aid to use your hand to hold something else, the Miniguide will then hang from the cord. Having the cord over your wrist is also a safeguard in the event of dropping it or having it bumped from your hand.
When storing the Miniguide, be careful to put it where heavy objects will not be dropped on it.
A list of the present modes and options, in the order in which they are selected is shown below. Following the list is a detailed discussion of each mode/option:
Mode 1 : This mode produces a feedback sound if there is a detectable object within 4 metres of the aid. The closer the object, the higher the pitch of the tone. As an object gets closer to the aid, the feedback tone will change every 2 centimetres ie. the resolution of this mode is 2 centimetres. The tone will keep changing until an approaching object is only 4 centimetres away. This is the default mode when switching on a new aid.
Mode 2 : This mode is similar to mode 1, except that only objects within a 2 metre range will produce a feedback sound.
Mode 3 : This mode is similar to mode 1, except that only objects within a 1 metre range will produce a feedback sound.
Mode 4 : This mode is similar to mode 1, except that only objects within a half metre range will produce a feedback sound. This is a good mode for beginners to try, since the feedback signal is less confusing.
Mode 5 : This mode has a 4 metre range, however the feedback tones are notes from a musical scale. The resolution of this mode is 20 centimetres, ie. the 4 metre range is represented by 20 different notes. A person with a good musical ear may find this mode easier to use than mode 1.
Mode 6 : This mode is similar to mode 5, except that only objects within a 2 metre range will produce a musical feedback sound.
Mode 7 : This mode is similar to mode 5, except that only objects within a 1 metre range will produce a musical feedback sound.WARNING: the following modes are only recommended for advanced users of the aid. Inexperienced users should only use modes 1 through to 7.
Modes 8 and 9 : These are the watchdog modes, Mode 8 has a 2 metre range and Mode 9 has a 1 metre range. These modes are used to indicate if anyone comes within 2 or 1 metres of the aid. The watchdog modes use much less power than the other modes. The lower power consumption is a result of the aid only scanning for objects a few times a second. This slower scanning rate also means that the watchdog modes cannot detect fast changes, so the aid should always be kept stationary in these modes eg. placed on a desk. In the watchdog modes the aid will switch-off automatically after about 13 hours (for other modes the switch-off time is about 1 hour). This allows the aid to be placed on a desk for most of the day. The watchdog modes also make an alarm sound every time they are switched-on. This is so that the user doesn't confuse these modes with the other modes.
NOTE: this is only a low power mode if there is nothing in the 2 metre (or 1 metre) range. Once an object is detected, the unit will use normal power until the range is clear (ie. when the feedback sound stops). In other words, it is only a low power mode if the feedback sound is off. Care must also be taken to ensure there are no soft furnishings (or similar) in the 2 metre (or 1 metre) range, such objects produce faint echos which may occasionally give false alarms.
Modes 10 and 11 : These are the "gap finding" modes, Mode 10 has a 2 metre range and Mode 11 has a 1 metre range. These modes have reduced sensitivity from a distance of half a metre and onwards. Only very strong echos from surfaces such as walls will be detected at distances greater than half a metre. This reduced sensitivity helps to distinguish openings or gaps in walls eg. door openings. As a safety precaution, the sensitivity for distances less than half a metre is the same as for all the other modes ie. full sensitivity. The "gap finding" modes make a distinctive beep sound every time they are switched-on. This is so that the user doesn't confuse these modes with the other modes.
WARNING: the gap finding modes should be used with caution. The reduced sensitivity of these modes means that fewer objects will be detected in the range half a metre onwards. For safety, it is best to assume that these modes are equivalent to Mode 4, ie. a mode with only a half metre range. It is also recommended that the gap finding modes are only used as a "quick select" mode (see options 17 and 18 below) ie. the user should use a full sensitivity mode such as Mode 1 or 2 most of the time, and only swap occasionally to Mode 10 or 11 when required.
Modes 12, 13 and 14 : These are the "amplitude" modes, Mode 12 has a 4 metre range, Mode 13 has a 2 metre range and Mode 14 has a 1 metre range. These modes are similar to the normal modes 1, 2 and 3. The difference is that the "amplitude" modes try to give an indication of the strength of the echo being received by the aid. A pipping effect is used to give an approximate guide to the strength of the reflected signal. A tone with rapid pipping indicates that the signal being received is relatively weak (eg. a signal from a cloth covered object, or door openings, thin edge etc.). A tone with no pipping indicates a strong reflection (eg. from a wall).
Mode 15 : This mode is used for testing purposes and is not to be used.
Option 16 : Selecting this option means that there will be only one setting active. When there is only one setting active, pressing the button will simply switch the aid on or off. This is the default state of the aid.
Option 17 : Selecting this option means that there will be two settings active. The user can swap quickly between two different settings. This is very useful if the user has two favourite modes eg. a 4 metre mode and a 1 metre mode. Assuming the aid is off, pressing the button will put the aid into the first setting (eg. 4 metre mode). Pressing the button again will place the aid into the second setting (eg. 1 metre mode). Pressing the button once more will switch the aid off. The aid will give one beep when setting one is selected and two beeps when setting two is selected.
The method for changing the mode used in setting 1 is no different than the method described in the section "Changing Modes" above. That is, with the aid presently off, press and hold the switch for two seconds or more. Changing the mode used in the second setting is done in a very similar way. The only difference is that instead of starting with the aid in the off state, the aid must be in setting 1. That is, with the aid presently in setting1, press and hold the switch for two seconds or more.
Option 18 : Selecting this option means that there will be three settings active. The user can swap quickly between three different settings. Assuming the aid is off, pressing the button will put the aid into the first setting (eg. 4 metre mode). Pressing the button again will place the aid into the second setting (eg. 2 metre mode). Pressing the button again will place the aid into the third setting (eg. 1 metre mode). Pressing the button once more will switch the aid off. The aid will give one beep when setting one is selected, two beeps when setting two is selected and three beeps when setting three is selected.
The method for changing the mode used in a setting is no different than the method described in the section "Changing Modes" above. That is, the user presses and holds down the switch for two seconds or more. The number of beeps counted after the two second gap determines the mode selected.
If the Miniguide is off and the user presses and holds the switch down (for longer than two seconds), then this will change the mode used in setting 1.
If the Miniguide is in setting 1 and the user presses and holds the switch down (for longer than two seconds), then this will change the mode used in setting 2.
If the Miniguide is in setting 2 and the user presses and holds the switch down (for longer than two seconds), then this will change the mode used in setting 3.
Modes/Options 19 and 20 : These modes/options are not used. They may be used in the future.
Option 21 : This option resets the software. That is, selecting this option is equivalent to removing the battery and pressing the button while the battery is removed (refer to the section regarding battery replacement for more information).
Option 22 : This option selects the lower pitch feedback tone. The aid normally produces a fairly high pitched tone (just over 1000Hertz) when objects are close to the aid. Some people may prefer a lower pitched tone. When this option is selected, a feedback tone one octave lower than the normal tone is used. The only way to return to the higher pitched feedback tone is to reset the aid (refer to Option 21 above).
NOTE: changing the pitch of the feedback tone is something you should only have to do once. That is, decide on which feedback pitch you prefer and then don't change it again. This is so that you can become familiar with the relationship between pitch and distance. Changing between lower and higher feedback pitch too often will only cause confusion and possible misjudgement of distances.
Option 23 : This option "locks" the current settings. This means that the current settings cannot be changed by pressing the button ie. holding the button down will no longer change modes. This option is useful in preventing accidental changes to the current settings. Organisations may find this option useful as a means of pre-programming an aid for a client. Once the lock option is selected, the only way of removing the lock option is to remove the battery and press the button while the battery is removed.