Previously:
Sci Fi Your Pi - Prince Dakkar's patent log taking chart compass
Sci Fi Your Pi - Prince Dakkar's patent log taking chart compass - Functional Design
Sci Fi Your Pi - Prince Dakkar's patent log taking chart compass - Route selection and indication
Sci Fi Your Pi - Prince Dakkar's patent log taking chart compass - Direction of Travel Indicator 1
Current Position
The plan was to indicate position on a decorative map using the GPS position from the GPS Module and then using that to move two long bar indicators to show that position on the map. This would maybe also have some artistic flair with the point that they cross decorated in some form (either an elaborate cross hair or a miniature steampunk style vessel).
To do this the GPS Module was to be used with the baseboard. As i described in the previous entry I failed to notice i don't have one so that plan changed and i am now using the GPS module without the baseboard.
The python library is used to obtain the position from the GPS module and then the fun starts.
I was intending to get a couple of stepper motors to help with exactly positioning the pointer on the map. This has not happened so i am intending instead to use two other motors i have lying around the house to drive the bars. The plan is to drive the motors using the Gertbot - (Data sheet) and try to use some cogs and gears to make the bars travel slow enough for drama and control.
i bought a lot of "steampunk cogs" from eBay but this was unfortunately not what i thought and instead of functional cogs and gears i could use it was a decorative assortment of bits for sticking on things. I am currently exploring the idea of 3D printing the required gears or just missing out that part of the design and programming the motors run slower. this may mean less accurate positioning (but we are talking about a pointer on a map of around A3 size so it is unlikely to be all that accurate anyway). This is probably a compromise that will be appropriate to the device as the adventurer only needs an approximate idea of his position or all the fun of the adventure would be taken away.
to move a bar along the map the motors will drive a belt at one end of the device. I did think about using a fixed bar but the space needed either side of the map meant that that was not feasible. so a loop that moves back an forward using only one motor looked like the best plan.
Before i could really progress i needed to find a map that suited the theme so i could work out how to move the motors. I mentioned before the difficulties in working with maps on a flat surface so I won't go into it i would either need to use a map that showed scale and shape accurately (but do more thinking and maths. I also wanted the vintage style feel appropriate to the theme of the device. As most of the Steampunk genre appears to be either set in the Victorian era of have elements of Victoriana I wanted to find a map from that era. I quite like the globe style maps that have a circle for each hemisphere (but not the programming headache that would present). So in the end i searched for a flat map that would be around the Victorian era.
This is what I found:
The map although not quite as an antique feel as i maybe wanted combines a Victorian style with the nice square grid pattern that will make moving the position indicator to a map position slightly simpler.
Now I have the map sorted I need to connect the motors up and experiment with speeds and times to move the pointers appropriately on the map. This will require finding / making an appropriate platform to sit this all on and making up the motor belts.