Everything is working!!!
This is the CatTrack Basestation communicating with the CatTrack unit on Buttons’ collar, showing his position on it’s LCD screen whilst simultaneously sending position information via Bluetooth to my laptop, which you can see on my screen in the background.
The LCD is showing Buttons’ latitude and longitude, along with the received signal strength in the top right (-81 dBm in the picture), the number of satellites being tracked by the collar (3 in the picture) and the horizonal dilution of precision (HDOP – basically a measure of positional accuracy). The HDOP in the picture is 4.4, represented on the LCD as 44. I ran out of characters on the LCD for the decimal point!
A closer look at the data that’s simultaneously being sent via Bluetooth to my laptop:
There is of course also the Beacon mode, which requests a single packet from the CatTrack collar containing just the collar battery voltage. This is so that you can monitor the collar battery voltage remotely from the basestation. You might check the voltage perhaps once a week.
Because a video speaks a thousand pictures (or something), here’s a video of that in operation:
The voltage on the home screen is the voltage of the battery in the basestation. I then cycle through all the options, before requesting a single beacon from the collar. After a few seconds (remember that the collar only wakes up once every 16 seconds to listen for transmissions), we get our reply – the battery voltage in the collar is 3.92 Volts. From the RSSI it looks like Buttons isn’t too far away either!
Some other features that now all work perfectly (eventually…):
- All RF transmissions are encrypted, with replay protection (read about that here)
- The Basestation will run from a micro USB connection or a lithium ion battery. The battery is charged when the USB is plugged in.
- The collar battery life is measured in months – around 4 to 5 months by my measurement, depending on how often you request the cat’s position.
I first got the collar working with a development board (instead of the basestation) a few months ago, read about that here.
Over the next few weeks I plan to write a tl;dr post to combine the whole story of getting to this point in one, concise post, to save having to trawl the entire site to relive the development.