LiveCode Forums

Hello, Iam new to Livecode and looking for a trainer or freelancer who can teach me how to create the following simple app.

The app checks the GPS position. If the mobile device reach a specific area (1 x 1m area) the app will give out a specific areabound information.
Information could be a picture, video or text. Or a combination of that.

Then the user getting a clou where the next area is. When he moving there, and is inside the perimeter, another information comes out. Is the user
reached all 10 areas (points) the game is over.

The idea is a little hunting game, with geofence option. iOS iphone only.

Hi,

You could just ask question on this forum. That might be as good as coaching. If you would like me to help you in a slightly more personal way, you can contact me here.

Kind regards,

Mark

pixeltodesign...

Are you wanting to display your GPS position on a 'google' map ?... It is certainly possible using liveCode on the iphone, you will struggle to reflect your position to within a 1x1 metre grid... ( the closest horziontal accuracy that I see from getting the current location is to within 10 metres... and vertical accuracy usually seems to be around 15-20 metres...)

Anyway, to answer your question ... Yes, it is certainly possible to make the game you wish to do from within liveCode.

I have attached a stack that will run in the iphone simulator or on your iphone that shows a google map running from within liveCode... it initially fires up over 'Wells,UK'... as that is where I live...

be well

Dixie

Hello,

thank you for your help.

I don't need to have a visible map.

My Idea is the following.

The app shows a picture. Something that the user can identify and know where the picture in real live was shot.
Example (a picture of the main station of my home town). The app gps is active and is checking when the person
is close the coordinates. The coordinates are latitude and longitude (e.g.) +40.689060 -74.044636.

If the app recognize that the user is close to the coordinates, or within a radius of 10m the app should show the next
hint. This time a small video. Then the same. User identify video. Walking to the area, gps in app recognize and
show hint 3.

I don't need a visible map but it would be eye candy feature

Since I have no knowledge and the app is planned as a birthday present, I would like to spend a few bucks for a programmer to
create the app and show me how to add my content. How long would you need for such an app?

pixeltodesign...

contact me at john@ihouse.on-rev.com

be well

Dixie

I can confirm that 10 metre accuracy is the best you'll get...

g

I sometimes see 5 m on my iPhones here on the prairies of North America without trees. With my Garmin handheld GPS i could sometimes get 3m accuracy which I believe is the limit of the unenhanced signal. Surveyors use other tricks to get their accuracy down to centimeters.

Kelly

Hi,
I thought that I would pitch in with some information about GPS. Standard GPS receivers use the CA code which is a data stream that the owners of GPS use to spoil to reduce the accuracy to approx 100m spherical. A few years ago they switched this data spoiling off meaning that the general public could use the system to its full accuracy. However, they may choose to spoil the signal at any time and may also use it in certain regions of the world. So what is the accuracy of the unspoiled signal? Well from memory its in the region of within 20 metres spherical 95% of the time. Most of this error is in the height channel so the X Y position is often much better.

There are also additional methods of improving the accuracy. Typically a fixed ground station looks at its GPS position and compares it with its known position and calculates a position delta. This delta is then transmitted to GPS receivers which apply the correction. The system is known as differential GPS and requires that the mobile unit be in Line of Sight of the fixed station. Differential GPS is used by maritime navigators as generally their GPS gains accuracy as they approach their destination port.

The next step was to rebroadcast the error delta mentioned above via satellite to improve its area of coverage. This system is known as Wide Area Augmentation System (WASS) and is available in North America and some other areas but not world wide. Most new GPS equipment is capable of using WAAS. I would guess that with WASS a GPS is accurate to a few meters most of the time i.e. 99%+ as it is used by aircraft for airfield approach.

The problem with raw GPS is the 5% of the time it is outside the 20m bubble. I once tried to implement a GPS based rally car time and speed system using raw GPS to provide the speed. The system sort of worked but massive errors in speed occurred because the position was always moving even though the GPS was not.

In summary the accuracy you will get depends on the type of GPS you own, where you are in the world as well as the number of satellites you are able to receive.

best wishes
Simon

That was a nice read Simon.

Thanks.