Tag: Design

More (Smart) LEDs

The Talisman V2 is using the CPU already included in the WiFi radio.  This Wifi CPU has less control wires made available than what was available from the independent CPU controller in Talisman V1.

In Talisman V1 there were 3 full color LEDs. Each full color LED used 3 wires – one wire for each of the red, green and blue LEDs. Therefore the Talisman V1 had used 9 control wires. (3 sets of 3 wires.)

Smart LEDs are being used in Talisman V2 to reduce the number of control wires. A large number of smart LED can all be controlled from one single control wire.

(This is achieved by sending the necessary color data for all the RGB LEDs over the single wire into the first LED. The first led then daisy chains the data passed along to the next LED in the sequence.)

The image above shows a V1 Talisman LED that with 3 wires on the left. On the right animated image is single smart LED. It can be seen in the right hand side photo that the little 5mm square LED has a dark chip rectangle and tiny gold wires within the white package. Each smart LED in V2 comes with a little chip inbuilt!

So, this posts shares how it is possible to reduce the number of data control wire by the use of smart LEDs from 9 to 1.  In addition it is possible to daisy chain a very large number of smart LEDs in a long sequence.

It is intended to add additional full color LEDs onto the Talisman V2, most likely in a circular ring or oval layout. This should allow the Talisman V2 to be orientated anyway an artists chooses. The Talisman V1 only had LEDs on the front edge, so V1 had to be orientated a certain way when artistically mounting.

Prototyping the smartLEDs today, uncovered a downside; they use power even when no light is being emitted! In fact their little internal chip uses so much power even when dark that they would over time significantly reduce the battery life.   For this reason it is necessary for the Talisman V2 to switch power off for the LEDs unless they are going to be shining.

It so happens that there is already a spare switched power available on the Talisman V2. The Talisman V1 used to have a Bluetooth controller that had it’s power turned on and off. This bluetooth is no longer required, so the second switched power is now used for powering on and off all the smart LEDs on V2.

Sugru and Conformal Coating Samples

The Talisman V2 is shifting the choice of the encapsulation or packaging of the internal electronics to other artistic people. it is suggested that one potential possible packaging could be the use of the end user mouldable Sugru.

A sample 3 pack of safe, family friendly Sugru has been ordered. The white color was choosen to allow the light from the colored LEDs on the electronics to shine through the hardened rubbery Sugru.

To ensure the waterproof seal and to avoid any shear stress ripping the electronics off the circuit board, a thin layer of clear soft rubbery “conformal coating” will be sprayed over the completed circuit board.

Coating the electronics in a paper thin layer of conformal coating will allow the encapsulated unit to receive thermal heating and cooling expansion and contraction movement, along with physical knock stress. The layer of rubbery conformal coating allows the components to squidge against the rubber layer.

Conformal coating is an expensive specialists coating, available in small quantities by 3M (via RS Components) as an aerosol spray dispenser can.

More power

In the Version 2 of the Talisman change to using a WiFi radio module has necessitated an increase in the capabilities of the power supply components.  The Wifi radio module requires more current be provided than was available in the original Talisman circuit. This has resulted in a simple upgrade of the voltage regulator to a different component that is capable of delivering bursts of more power.


The selected voltage regulator, AP2112_3.3 is the same physical size as used on the original Talisman. Upgrading the power supply section of the electronic design will ensure that the upgraded radio module will be able to obtain stable WiFi connections.

Replaceable Battery

The design revision for Talisman V2 includes the ability to replace the rechargeable battery without the need to solder. The Talisman V2 uses a plug in connector between the battery and the main circuit board.


This will allow the installation of a replacement battery without the need to solder the two battery wires.  The actual ability to replace the battery will depend on the case encapsulation used and choosen by the various artists.

In theory it should be possible to cut and peel away any silicon rubber case from Sugru. The actual reality of being able to remove whatever case is used is questionable. However assuming the artist’s case can be removed, the use of a connector removes the earlier requirement for soldering the battery.

The images show the battery with the plug on the end of the battery wires, and the white socket that is soldered onto the main electronic circuit board.



Version 2 – Upgraded CPU with WiFi

Initial feedback on the Talisman V1 confirmed the requirement to minimise size and simplify the usage.

If the Talisman were able to connect directly to WiFi this would simply the deployment because the use of a bridge would no longer be necessary.


A search of the available radio modules resulted in the selection of an extremely low cost WiFi module from ExpressIf in China. The ESP-07 WiFi module provides WiFi ability. The module can connect to an existing internet WiFi network as a client. This network would be a user’s home WiFi network, or a WiFi network shared from the users roving mobile handset. Most mobile devices can act as a AccessPoint, sharing their cellular mobile internet access on a password protected WiFi network. This is simple to use and just requires turning on on a mobile device.

The ESP-07 also can act as an Access Point. This is useful because it allows the module to provide a WiFi network that the user can connect to. A user could connect to the module in the Talisman V2 using their laptop or mobile phone. The user would simply select the Talisman V2 provided WiFi network from the list of available networks on their mobile or laptop.

Once a user connected to the Talisman V2 they could browse to a Talisman V2 provided web page and enter the details of their home network.

Having the Talisman V2 provide a WiFi network with a single simple web page for entering network name(s) and password(s) allows the user to configure the Talisman to use their password protected home WiFi network.

The ESP-07 WiFi module can obtain the RSSI signal strength of nearby WiFi networks. This will be used to detect the close physical proximity of the Talisman V2 to beacons.

The ESP-07 also provides access to store data and downloaded apps. The ESP-07 can be programmed to run the apps. Therefore using the ESP-07 would no longer require a seperate micro-controller. This reduces the number of components, and allows the design to be shrunk in size.

Given that the ESP-07 radio module provides WiFi and can use RSSI to detect nearby beacons, the Bluetooth module can be dropped from the hardware design.

It is proposed that the Talisman V2 would use the ESP-07 WiFi module and no longer require or support the use of bluetooth.

All the features mentioned above are being tested to ensure the functionality works as expected. A more comprehensive post will be made showing this version 2 parts prototype.

Initial Possible Portal Page Sketches

Prior to creating the portal it would be excellent to hear feedback and get suggestions for improvements or alternative layouts.

The first few most important end user pages are sketched below. The first thing to note and discuss is the simple layout with a single Stack Layout on the left.

An implementation using the suggested Stack Layout would be simple and similar to how an online email program is presented.

Login and Dashboard

A left most column would allow the end user to select between the main sections of the site: Dashboard, Settings, Devices, Apps, and Resources. Each section would have an icon and label on the left. Some of the sections, such as the devices section would have a further tree type list on the left under the section heading.

Stack PanelAn example of the Stack Layout is shown on the right.

The rest of the page area on the right would then contain the content relevant to the selected section.  Some sections such as settings would be able to be contained on a single page and therefore not require any sub-section list or tree on the left under the section heading.

The sketches cover the login page that is always in English. (All other pages will be able to be localised.)

The Settings page has little data given that little personal information would be initially collected.  The content on the right on all pages would flow, so could suit a more narrow mobile device as well as a desktop or laptop viewing screen size and aspect.

The dashboard is intended as a flexible first page to quickly show the end user a summary of their most important dynamic information.  Some of the quadrants on the dashboard could be uniquely developed as apps (based on use cases) are added.

Settings Devices

The media resource section is critical, and will likely have to be reimplemented with more design and usability that sketched here. The initial sketch is based on the boring but effective file explorer model, The user could sort all audio, video, image and documents. The initial sketch shows just a name field to describe the resource. More polished usable details could be added, potentially including things such as descriptions, previews, search-ability, keywords etc.

Media and Bridge

Most of the organisation of the worn devices, the hardware or  Andoid bridges, and any beacons will occur with a tree list on the left within the Stack Layout section.

Details on the selected would then be sown on the right. Most fields other than name, would be informative and non editable. Improvement of the interface to include for example a chart showing battery life rather than a single current charge percentage could be added in the future as required.

The Apps section is not sketched but could include a simple list of all apps in the Stack Panel under the section. Any used apps would be checked in this list.

The currently selected app would show details on the right content area. Most likely some apps will have app specific settings. Most apps will also have the ability to populate a quadrant on the dashboard with results. Perhaps the end user could select which if any views of an apps results are included in the dashboard.

The dashboard would likely require a carousel to rotate quadrants should the user choose to display more than four quadrant result views.


It is not clear where options and information about the process of working through he ID steps in a structured course should go. Potentially a retreat or course section could be needed to clearly organise the steps in a program, the contemplations, active apps for that week, etc. Rather than try to guess in advance all required data, a don’t know mind-state is held. Keeping the site small, simple and clean leaves space to add some additional sections as required.

It is hoped that the same site would be used for internal stuff. A internal staff user would log in to the same site and be presented with more stuff for the additional more complex staff tasks. The additional appearance of more sections would occur based on the permissions and rights of the user who logged in. There would be once site that changes what is included based on the username.

It was initially expected that a row or two of toolbar buttons would be required, but perhaps for the end user things can be kept simple enough to not require any buttons.

The pages for the internal organisation of media resources, for design of courses, for management / inventory of Talisman, for site administration are almost certain to require the addition of one to two rows of context relevant buttons at the top.

The addition of many toolbar icons would likely make the management site more suitable for a landscape desktop or laptop browser, which should be acceptable.