Tag: Bluetooth

Network Data Layer Draft Doc

The draft of this document was prepared some time earlier, and not posted.

Data Transport Layer – Draft

This doc is due for an update to include details of simplified message types that resulted from discussions between Nader and Allan.

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Potential Hardware Bridge module

In the Transport Layer document, the requirement for a dedicated hardware Bridge was discussed.

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This device would require locating some sort of WiFi module to connect to the internet, and a Bluetooth 2.0 radio to communicate with the Talisman radio.

Above is a photo of a hardware module that does everything required, readily available at low cost, and easily programmed to act as a relay bridge.

This ready assembled module includes a WiFi module, a microprocessor to control the basic relay of the messages, and a Bluetooth radio. It is to be confirmed that the Bluetooth Radio is compatible with the 2.0 and BLE versions, which means this unit could support current Bluetooth 2.0, and also any future Bluetooth BLE iPhone radios.

The unit is available already assembled, and can be powered by simply plugging any readily available phone charger cord into the USB charge type socket on the module. The socket to plug the USB power cord is seen on the right of the unit half way along the short side. The socket accepts the standard slim USB cable used for Samsung phones etc, and appears in top down view as a silvery rectangle in the photo (between the EN and BOOT white lettering).

The unit could be very cheaply enclosed in black shrink plastic. There is no requirement to solder anything onto the unit. One end with the power USB socket would remain visible.

A sample of this device is being shipped to Allan, and if it is as listed would immediately fulfil all the current (and future) requirements of a dedicated Hardware Bridge.

This is excellent because it could remove the need to design our own Hardware Bridge circuit board, remove the need to source components and locate an assembly factory.

The unit can be obtained in single units, or hundreds of units from China from multiple suppliers under $8 USD per unit, delivered. The unit would require the program that would relay the data to be loaded into each unit using a cable. This is a simple plug the cable and click a program button operation that does not necessarily require an electronics person with soldering skills.

The end user would bring their home WiFi network name and password to the induction event. They would then be guided through a very very simple process where they enter these two pieces of information into their Hardware Bridge. This could be done very simply by browsing to the Hardware Device using any mobile phone and entering the network SID and password into two fields on a simple web page.

The settings for their home WiFi network would then be stored on their device.  Once home, the user would find a spare wall plug pack used for charging a cell phone, plug the cable into the Hardware Bridge, and place the unit somewhere in their house out of the way.  They would not have to do any else.

(Allan also ordered a range of Bluetooth BLE modules to allow testing what hardware would be required to support iPhone bridge. Any iPhone Bridge would require a redesign of the Talisman PCB to accomodate a different iOS capable Bluetooth BLE (not the existing Bluetooth 2.0) module.  A selection of various available Bluetooth BLE modules from each of the major Chinese manufacturers was ordered.)

Bluetooth Proximity (in parcel)

The talisman will make use of BlueTooth for both communication bridged to the internet and also to detect the proximity of the talisman to beacon units.

 

To confirm the use of the RSSI (Radio Spectrum Signal Strength) and determine the available accuracy and range a device was built.

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The Bluetooth Proximity device has an internal microprocessor, BlueTooth Module and a 2 line LCD.

After starting, each row in the LCD shows the signal strength reading for each of two example beacons.  This shows that it is possible to detect when the talisman is within proximity of one or more beacon units.

The beacon units are very simple and contain a low cost bluetooth module that is simply permanently powered via a wall plug pack or other USB power source. There is no requirement for the beacon to contain any microprocessor or to connect to the internet.

To test the proof of concept the two beacon should be plugged into a USB power source, and placed in two rooms around a house. Then the LCD display unit should also be powered via the USB cable and moved around to allow observing the possible detection range and accuracy.

Wireless Bridge – USB Module Parts

The parts to be used in the dongle that plugs into a computer arrived. The particular USB Module chosen was selected to work out of the box without requiring hunting for USB drivers.

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This module will be in a small enclosure along with a wireless Bluetooth module.

Together the USB module and the Bluetooth Module will allow a program running on a computer to bridge from the server, over the internet, through the USB module, into the Bluetooth module, over the RF airwaves, into the Talisman Bluetooth Module and finally onto the Talisman device.