Updated: Saturday 11 February 2023

This is the instructions manual for the M!nder.

Unboxing Test
Informational Sounds
Hanging Position
Rain, Liquids and Moisture
Upgrades & Repairs
__Version Numbers
__Opening the M!nder
__Battery Replacement
__Battery-Pack Upgrade
__PCB Replacement
__PCB Firmware Upgrade
__Hanging-Plates Replacement
__Siren Replacement
__Enclosure Replacement

Unboxing Test

When you receive your purchased M!nder, it is natural to want to try it. Indoors, you ought to wrap the M!nder in a thick blanket, so as not to startle anyone; outdoors, please conduct your test far away (200+ meters) from other people.

  • Power the M!nder on: Press the power button until you hear 1 beep.
  • Type-in the default password, 1234.
  • If indoors, quickly cover it under a thick blanket.
  • After about 8 seconds, the system activates. Shakes may then lead to responses.
  • To de-activate, wait for any movement to subside, then type-in the password. The system will automatically power down.

Now, change the password.
Then record all the version numbers for future reference.


When you arrive at your parking spot:

  • Lock your bicycle with a D-lock/U-lock.
  • Take the M!nder out of your pack/bag/pannier.
  • Attach it to your bike or D-lock/U-lock, using a suitable padlock. Select a position that allows the M!nder to hang as freely as possible.
  • When you are ready to leave your bike, power the M!nder on: Press the power button until you hear 1 beep. (If the batteries have insufficient charge, you will also hear 3 beeps, followed by automatic power-down. Do not leave the M!nder on your bike, as it may then be attacked.)
  • Type-in your password. A good password will result in 2 beeps; a bad one, 3 beeps.
  • After the 2-beeps, the power button is disabled.
  • You now have about 8 seconds before the system activates, at which point you will hear another 2 beeps.

When you return to your parking spot:

  • Be careful not to move the bike; the system is alert! If it has been recently tampered with, the system will be in a _heightened_ state of alert!
  • Type-in your password to de-activate it. You will hear 2 beeps (for a good password; 3 beeps for a bad one), and the system will automatically power down.
  • Unlock the padlock, and detach the M!nder. Place it in your pack.
  • Unlock the bike’s D-lock/U-lock.

Informational Sounds

  • 1 beep: Power on.
  • 2 beeps: Good. (e.g. good password.)
  • 3 beeps: Bad. (e.g. bad password.)
  • 1 long beep: At the end of your parking session, you’ll type-in your password, hear the 2-beeps of a good password, then the system will automatically power down. If, however, the 2-beeps is followed by a single, long beep, then something bad happened during that session! The longer this beep, the worse the event(s) was:
    • 1 second is a caution;
    • 2 seconds is bad;
    • 3 seconds tells you not to park like that again (i.e. at that place/time/day/duration/anchor with that lock/bike)!


When you purchase a new M!nder, it arrives with a default password of ‘1234‘. This must be changed immediately, or your bicycle will be stolen!
To change the password:

  • Write down your new, four-digit password. There is no password-recovery mechanism if you forget your new password! This is a security device.
  • Power-up the M!nder;
  • Type-in your old password;
  • After you hear the 2 beeps of a good password, you will have about 8 seconds to change your password:
    • Type ‘4‘. You’ll hear 2 beeps.
    • Type-in your new, four-digit password. You’ll hear 2 beeps.

Keep a written record of your password, preferably on a piece of paper you keep at home. Do so _before_ you change it! Do not carry it on your phone. Do not share it with anyone.

Whenever you are entering a password, type carefully. If there are too many failures, the system will get hyper, and might lock you out of typing, for a while.
Once activated, the system will not allow itself to be de-activated unless all movement has ceased. As such, if a thief has abandoned the theft attempt, ensure that the bike is stationary, before you attempt to type-in your password. You may need to wait for a few seconds!

‘I Forgot My Password!’

You’re out of luck!
You’ll have to replace the mother PCB, or send it back to me for resetting.
If the system has been activated, you’ll have to wait till it runs out of battery–which might be much longer than you expect! Tampering with it will cause it to think you a thief.
If the system is powered-up but not activated, you could open the enclosure to disconnect the battery, thus powering it down.

Hanging Position

The M!nder must be hung where it can swing freely.
The higher the position of the lock, the better.
There is no perfect position, and different bikes have different limitations. Add to that the different anchors and the different parking situations (location, time, duration, weather, lock type, appeal of the bike).
Given the above limitations, the option available on most bikes may be to hang the M!nder from a D-lock/U-lock that locks the top-bar of the bike to a dependable anchor. But, your bike, and your parking situations, may offer safer options.


Do not rattle the M!nder. It must be treated with care. There are objects within which are loosely placed.
Do not drop the M!nder. It is not designed to survive impact.
Do not expose the M!nder to significant rain; it has not been tested for that.
Like all metals, the mounting plates need to be protected against rust.

Rain, Liquids and Moisture

The M!nder has not been tested for prolonged exposure to rain. Operation may be affected, and damage may occur over the long term.
Like all metal, the plates used for hanging the M!nder will need care against rust. Even if the plates’ visible, top surfaces are regularly coated, and kept dry, the invisible, bottom surface of a plate might develop rust. Conceivably, the plates could be periodically unmounted to apply rust-protection, but this has not been tested.


The M!nder has not been tested at 0 C or below, and is not expected to have reliable operation at those temperatures. Like with other lithium batteries, prolonged exposure to cold temperatures approaching 0 C will shut the device.
The M!nder is suspected to operate at up to 40 C, though it’s not been tested for that.


After about 10 hours of usage, you should recharge the M!nder. An AC adapter with a suitable barrel jack must be used for this purpose; it must provide a current of 1 A (no more than 2 A), and a voltage between 8.4 volts and 15 volts.
The barrel jack must be 5.5×2.1 mm, with a _positive_ centre. In U.S. & Canada, this is the most frequently available.


Never activate the system on a bridge, or at locations similarly subject to frequent shaking. In particular, trains passing on a metal bridge will set off the siren!
While the system makes its best effort at reducing false alarms, it must err on the side of caution. As such, it is possible for the system to react when it should not. Passing, heavy trucks might generate responses, to cite another example. And, when returning to your parked bicycle, the system may be hyper-responsive due to a recent theft attempt, movements or tampering.

Upgrades & Repairs

This section is a work in progress, expected to be completed by Spring 2023. As of December 2022, sales have not begun.

Repairability and upgradeability, if at all available, are at the discretion solely of the inventor of the M!nder.
You will need the tools for the tasks.
You will need to follow the instructions carefully, including those shown in video.

No guarantee is provided.
You are solely responsible for any changes.
Your warranty will become void.

Version Numbers

It is imperative that you note all the version numbers of the M!nder(s) you have. Parts are not interchangeable. It is your responsibility to ensure that the replacement, or upgrade, parts which you purchase will match the M!nder for which you purchase them. If you have any doubt, contact me beforehand.
The following are noted inside the enclosure as well as on a sheet inside the shipping-box you received the M!nder in:

  • M!nder‘s version number
  • Mother PCB‘s version number
  • Daughter PCB‘s version number
  • Firmware‘s version number
  • Enclosure‘s version number

If you replace any of these parts with one of a different version number, you must keep a record of the new number. This is particularly crucial in the case of the PCBs (i.e. the electronics hardware boards) and the firmware.

Opening the M!nder

This is the procedure for opening the M!nder device.

  1. Ensure that the system is de-activated and powered down.
  2. Unscrew the closure bolts. (These are M2, or M3, metric bolts with a hex head.)
  3. Tilt the M!nder in such a way that its control panel will face slightly downwards.
  4. Pull the control panel out, all the way.
  5. Behind the control panel, you will find, in order: the daughter PCB (attached to the control panel); a bundle containing the battery pack and the mother PCB; the siren.
  6. If you will need to extract the battery pack, or the mother PCB, you will need to open their bundle.

Battery Replacement


If the user decides to purchase the battery-pack elsewhere, it may well be incompatible–in wiring, chemistry, recharging, discharging, protection, size. Of all of these crucial factors, size is the most manifest to a lay person: Higher-capacity packs are larger, and may well not fit within the M!nder’s enclosure. Damage to the M!nder, and personal injury to the user, are likely when the other factors are ignored.

The system comes with 2 Lithium (li-ion) batteries, in series. 3.7v 18650 2S 1500 mAh, with a thermistor. Like all lithium batteries, there is a limit to the number of recharges, and the shelf life. The pack is vulnerable to the usual limitations of lithium batteries: cold/temperature, fire, puncturing, etc.
Once it can no longer maintain a charge, the pack must be replaced with a similar pack. (See Upgrades.)

If the M!nder has been attacked, vandalized or otherwise damaged, inspect the batteries for damage. As with all lithium batteries, the M!nder’s batteries are vulnerable. After an attack, they may well be dangerous to use, and will need to be replaced.

Procedure for Replacing the Battery Pack

  1. Follow the instructions for opening the M!nder;
  2. The mother PCB is wrapped in heat shrink. You will need to carefully cut this, without damaging anything within.
  3. For greater ease, you may disconnect the siren’s wire from the mother PCB, at the terminal labelled “Siren”. This will allow you to work without being tethered to the siren.
  4. Disconnect the battery pack from the mother PCB, at the terminal labelled “Battery”.
  5. Connect the new battery pack to the same terminal.
  6. Reconnect the siren tot he mother PCB.
  7. Slide the mother PCB into the heat-shrink tubing provided with the new battery-pack.
  8. Use a hair dryer, at a low to medium temperature, to shrink the tubing to fit.
  9. Re-pack everything into the enclosure.
  10. Fit the control panel into the enclosure, and screw the closure holes tightly.
  11. The M!nder should now be ready.

Battery-Pack Upgrade

As yet, a higher-capacity pack is not available for sale on this site. And none has been tested that will fit the current enclosure.

PCB Replacement

As yet, PCB replacement has not been set up for sale on this site. The following is instructions I am adding in preparation.

Replacing the PCB is not a trivial task! If you are not conversant with electronics and printed circuit boards, take your M!nder to a technician.
Even if you are used to such work, film the unpacking of the M!nder and the disassembly of the wiring of the existing PCB. This should be of use when time comes to put everything back together.


This is the mother board–the main board.

  1. Follow the instructions for opening the M!nder;
  2. The mother PCB and the battery pack are wrapped in heat shrink. You will need to carefully cut this, without damaging anything within.
  3. Disconnect the siren’s wire from the mother PCB, at the terminal labelled “SPB”. This will allow you to work without being tethered to the siren.
  4. Disconnect the battery pack from the mother PCB, at the terminal labelled “Battery”.
  5. Disconnect the mother from the daughter, at the terminals labelled “SW”, “Vin” and “Bus”.
  6. Connect the new mother, as above.
  7. Bundle the mother and the battery-pack with the provided heat-shrink. Heat the bundle using a hair dryer, on a medium setting, until it shrinks to fit the bundle.
  8. Pack everything back into the enclosure, then power-up to test.

It’d be best to keep the old mother PCB. It can be used if you ever send the new mother to me for a firmware upgrade.


This is the secondary/daughter board.
(It will arrive with LEDs and a power button already soldered to it.)

  1. Follow the instructions in the Mother section, above, till the point where you have detached the mother from the existing daughter.
  2. Unscrew the bolts holding the daughter onto the back of the control panel.
  3. Replace the existing daughter with the new one.
  4. Screw the new daughter onto the back of the control panel.
  5. Reconnect all the wires.
  6. Power up the system to test.
  7. Pack everything back into the enclosure.
  8. If needed, apply clear silicone around the power button, to protect it from dust and moisture, and let it cure undisturbed for a day.

PCB Firmware Upgrade

As yet, firmware upgrades have not been set up for sale on this site.

Overview: Send your mother PCB to me; I will upgrade its firmware, and will ship it back to you. The firmware and both shipments are paid-for by you. It’d be practical to have a spare M!nder/mother to use while awaiting the return shipment.

  1. Contact me with all of your version numbers to ensure compatibility, and confirm the shipping process.
  2. Follow the instructions in the Mother section, above, till the point where you have detached the mother from the existing daughter.
  3. Pack it carefully into a box.
  4. Pre-pay for the shipment, both ways.
  5. Ship the mother PCB to me. You will receive an email from me when the PCB has been received.
  6. You will receive an email from me when the upgrade has been completed.
  7. You will receive an email from me when the shipment is sent.
  8. When you receive the shipment, send an email to me.
  9. Connected the mother to the rest of your M!nder, and power up to test. Place the new Versions Sticker into the enclosure, and keep the printed receipt (which has an updated Versions Sticker) alongside your original sales receipt.

Hanging-Plates Replacement

As yet, replacement mounting-plates have not been set up for sale on this site.

  1. Follow the instructions for opening the M!nder.
  2. Unscrew both plates, to replace them with the new ones. (If you know how to disconnect the siren from the mother PCB, it may be easier to temporarily do so.)
  3. After both plates’ bolts are tightened, re-pack the enclosure, close it, and screw the two plates together.

As noted under Care, the metal plates must be protected against rust.

Siren Replacement

As yet, replacement sirens have not been set up for sale on this site.

  1. Follow the instructions for opening the M!nder.
  2. Disconnect the siren’s wire from the mother PCB.
  3. Extract the bundle which contains the mother PCB and the battery pack. The main body of the enclosure will now contain only the siren.
  4. Unscrew the two bolts which attack the siren to the main body of the enclosure.
  5. Replace the siren with the new one, and screw the bolts back in.
  6. Connect the siren’s wire to the mother PCB, and pack the bundle back into the enclosure.
  7. Close the enclosure, and screw the two plates together.
  8. Power the system on, to test.
  9. Type your password in.
  10. Immediately place the M!nder under several layers of a thick blanket.
  11. Shake the M!nder to hear the siren’s sound.
  12. Power the system down by carefully typing your password in, without moving the M!nder.

Enclosure Replacement

As yet, replacement enclosures have not been set up for sale on this site.

  1. Follow the instructions for opening the M!nder.

If you need to replace the main body of the enclosure:

  1. Disconnect the siren from the mother PCB.
  2. Extract the mother bundle.
  3. Unscrew the siren’s bolts.
  4. Extract the siren.
  5. Unscrew the bent plate to detach it.
  6. Connect all of the above to the new body.
  7. Re-pack the enclosure; screw the two plates together, then power up to test.

If you need to replace the control panel:

  1. At the mother PCB, disconnect the wires leading to the daughter PCB. The terminal, on the mother PCB, is labelled “Vin”.
  2. Unscrew the barrel socket from the Control Panel, to unmount it.
  3. Unscrew the daughter PCB from the inside of the Control Panel.
  4. Disconnect the keypad’s ribbon from the daughter PCB.
  5. Peel off the keypad, and pull it out of the Control Panel.
  6. Unscrew the flat plate.
  7. Mount everything onto the new Control Panel.
  8. Connect the barrel socket’s wires to the mother PCB’s “Vin” terminal.
  9. Power up to test.
  10. Type-in your password to power down.
  11. Pack everything back into the enclosure.
  12. Screw the two plates together, to close the enclosure.