I know a few people are now watching this and I wanted to keep you informed of my approach/progress. I spent some of yesterday laying out a PCB using Cadsoft Eagle program in order to use the PIC16LF1824 IC – the plan was to mount the TSSOP packaged IC along with a PCB etched antenna. This was the start from yesterday – which I must point out is not finished, so don’t try and use it ! There were three push switches (top right) to vary the pulse pattern, some LED indicators below, an In-Circuit programming header (top left), the TSSOP microcontroller (mid-left) and the PCB antenna at the bottom. I used the Texas Instruments design note DN024 to draw this out.
After getting some of the circuit and PCB drawn I realised I didn’t have several of the components required for the antenna and would have to place an order – mainly the very small value inductors. My usual route of purchase in the UK is CPC Farnell as they have free delivery on orders above £5 – but they had limited choice of parts. Thinking ahead I’d have to buy parts, await delivery, struggle to make a PCB (as TSSOP is possible but really challenging for me using my homemade PCB methods), construct the circuit and then finally start to work out what signals makes the Xyloband work.
I wanted a quicker and more reliable approach so had a look on Ebay and found this module, which is now on order and hopefully turning up in the week (10th August 2016). e.g. my first approach but a bit cheaper than the Maplin version.
The module needs controlling from another host microcontroller but I’ll be able to make all that part on my breadboard. I plan to try out Frequency Shift Keying (FSK) and On-Off Keying (OOK). Try some simple repetitive pulse patterns of different pulse width and repetition rate. I’ll also try out some 8/9 bit patterns with a start and stop bit as used for asynchronous communications.