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Topic: gps guided robot (Read 1 time) previous topic - next topic

mohammadzm

hi everyone
i want to create gps guided car with this module:
u-blox neo 6
arduino mega
HMC5883
l293 shield
6wd Chassis kit -> https://www.sparkfun.com/products/11056
please help me in code
thanks :D

vinceherman

This appears straight forward.

Break the project down into doable chunks and then combine.
Start with a Hello World tutorial like Blink to make sure you can upload a sketch.
Then work on a sketch to use your motor shield to drive the motors in the chassis.
Then a sketch to read values from your compass.
Then a sketch to read values from your GPS.

Then start combining pieces.

Add in a method to enter a destination or route with waypoints, and then logic to use all of that data to perform navigation.

If at any point, you run in to difficulties, pop back here and let us know.

mohammadzm

thanks for your reply
my main problem is how to navigate my car to special waypoint
when to start motor and when to stop them and when to rotate the car

jremington

#3
Nov 28, 2018, 11:03 pm Last Edit: Nov 28, 2018, 11:06 pm by jremington
Quote
my main problem is how to navigate my car to special waypoint
Pretty simple, actually. The navigational formulas are presented on this site: http://www.movable-type.co.uk/scripts/latlong.html. You will need the bearing and distance formulas.

One problem is that the Arduino does not support double precision floating point calculations, which is usually required for navigation using latitude and longitude coordinates.  Some GPS libraries, like NeoGPS, get around this by using long integers for latitude and longitude variables.

Note: the L293 motor driver WILL NOT WORK with the motors used in the "Wild Thumper" vehicle you have selected. You need a high current motor driver.

mohammadzm

thanks for your reply
i will try that formulas
i will use 2 of l293 shield
i try that and have no problem in short use each l293 shield can handle 4 amper am i correct?
i use this
https://goo.gl/images/rZ82UP

jremington

#5
Nov 29, 2018, 04:44 pm Last Edit: Nov 29, 2018, 04:47 pm by jremington
Quote
in short use each l293 shield can handle 4 amper am i correct?
No. It will overheat and shut down instantly.

The motors have a start/stall current of around 6 Amperes.

Do have fun trying, though!

mohammadzm

i have problem with compass my hmc5883 show different heading angle from my phone
for example my phone shows 180 degree but my sensor shows 342 degree

jremington

Magnetometers must be calibrated in order to use as a compass.  See this post and the links therein.

mohammadzm

thanks
can you send a working sketch i try many but none of them works :smiley-confuse:

jremington

The link in reply #7 contains a sketch that works for a particular magnetometer.

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