I am using a STEVAL-STLKT01V1 development kit. The sensor tile is the smallest IOT module I have seen. The sensors I am going to focus on are:
1. LSM6DSM - inErtial module, 3D accelerometer and 3D gyroscope
2. LSM303AGR - eCompass module with a 3D accelerometer and a 3D magnetometer
When Element 14 sent me the Arduino Uno I had no idea that I could program the sensortile using Arduino sketches. That simplifies the programming process and certainly makes it easier. The Arduino Uno has a connector layout and it was just a matter of attaching the sensortile cradle expansion board on top of it and then attaching the sensortile.
I have a draft sketch prepared and still have some work to finalize and test the sketch.
Draft Sketch
The goal is to program the sensortile to use a inertial navigation model in which accelerometers and gyroscopes are used to track the position of a object relative to a known starting point. Below is a draft sketch to be developed to achieve this goal.
//Radius of Earth
R = 6378.1
//Calculation of Bearing
brng = Math.atan(magY/magX)
//Calculating distance
d = Step has been taken * stride
//Starting latitude converted to radians
lat1 = 52.20472 * (math.pi * 180)
//Starting longitude converted to radians
lon1 = 0.14056 * (math.pi * 180)
//Calculate next latitude
lat2 = math.asin( math.sin(lat1)*math.cos(d/R) +
math.cos(lat1)*math.sin(d/R) *math.cos(brng))
//Calculate next longitude
lon2 = lon1 + math.atan2(math.sin(brng)*math.sin(d/R)*math.cos(lat1),
math.cos(d/R)-math.sin(lat1)*math.sin(lat2))
//Convert latitude to degrees
lat2 = math.degrees(lat2)
//convert longitude to degrees
lon2 = math.degrees(lon2)
//print results
print(lat2)
print(lon2)
Distance will be calculated by whether a step has been taken The project is designed for a person or animal. If a step has been taken than the stride will be the distance.
length = sqrt(x * x + y * y + z * z);
if(length>=2){
stepcount+=1;
}
Once the Sensortile has been programed than I will solder the tile to a smaller cradle. The cradle will be powered by a tiny battery and be placed in a plastic case.
