shammi kumar
The Program derives motor bots getting instructions(speed, turn, stop,etc) from accelerometer.
Dependencies: Motordriver mbed
Revision 0:c5c22fd71be8, committed 2013-10-27
- Comitter:
- samgang
- Date:
- Sun Oct 27 16:42:08 2013 +0000
- Commit message:
- Initial Commit
Changed in this revision
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Motordriver.lib Sun Oct 27 16:42:08 2013 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/littlexc/code/Motordriver/#3110b9209d3c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Sun Oct 27 16:42:08 2013 +0000
@@ -0,0 +1,61 @@
+/* This program uses Christopher Hasler motor library to derive DC motors */
+
+#include "mbed.h"
+#include "motordriver.h"
+
+// Array of Motor type objects to define 4 motors for two bots.
+Motor M[]= {Motor(p25, p9, p8, 1), Motor(p26, p11, p10, 1), Motor(p21, p13, p12, 1), Motor(p22, p15, p14, 1)};
+// Array acc defines 4 analogin type objects to detect inputs of accelerometer.
+AnalogIn acc[]= {p16, p17, p19, p18};
+/*@update reads recent values from accelerometer and uses them to control motors
+ @param 'a' tell for which bot the vales should be updated( a=0 for 1st bot and a=2 for 2nd bot)
+*/
+int update(int a)
+{
+ float offx=0, offy=0, map=0, turnp=0, turnn=0;
+ /*output votage of accelerometer at x and y outs when x=0 and y=0;
+ turnp and turnn specifies the positive and negative voltage difference(CurrentVoltage - offset) detected from offset value when accelerometer is tilted.
+ I will be using turnp and turnn as the minimum required voltage difference(ie, the minimum required tilt) to turn the bot.
+ The value below are default ones for my accelerometer
+ */
+ if(a==0) {
+ offx=0.340;
+ offy=0.340;
+ turnp=0.032;
+ turnn=0.055;
+ map=14.68;
+ } else if(a==2) {
+ offx=0.350;
+ offy=0.440;
+ turnp=0.040;
+ turnn=0.045;
+ map=13.40;
+ } else
+ return(-1); // return -1 as error when update is called with unexpected argument value
+ float s=0, st=0;
+ s=acc[a+1].read();
+ s=(s-offy)*map; // multiply by 'map' to linearly map difference (s-offy) to euivalent scale on 0 to 1 so that s can be used as speed
+ // (s=0 for (s-offy)=0 and s=1 for max[(s-offy)] )
+ st=acc[a].read();
+ st=st-offx;
+ if(st>0 && abs(st)>turnp) { // checking whether to turn or not ( st>0: right turn and st<0: left trun)
+ M[a].speed(0);
+ M[a+1].speed(1);
+ } else if(st<0 && abs(st)>turnn) {
+ M[a].speed(1);
+ M[a+1].speed(0);
+ } else { // if no turn input then run both motors with speed s
+ M[a].speed(s);
+ M[a+1].speed(s);
+ }
+ return 1;
+}
+
+int main()
+{
+ while(1) {
+ update(0); // Calling update for first bot(a=0) and second bot(a=2)
+ update(2);
+ wait(0.2);
+ }
+}
\ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Sun Oct 27 16:42:08 2013 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/a9913a65894f \ No newline at end of file