Update README.md

README.md

@@ -4,12 +4,23 @@ PIDMotorControl Example includes code for DAC, ADC, PWM, Timer Interrupts,
 PID, Current Control, Encoders w/ interrupts, pins, clock frequency setup, and low pass filters
 
 
+DAC()<< example in this code is meant only to use DACB due to poor construction
+Used to convert digital signals to analog signals - really useful for debugging on scopes
+
     DAC
+    CTRLA - enable a channel on the DAC, and enable DAC
+    CTRLB - set DAC to single channel use or dual channel use
+    CTRLC - Set the reference voltage
+    
+    DAC Channel
+    DACB.STATUS - used to check if its ready to convert again.
+    DACx.CHyDATA - 12 bit value to output
 
 
 
 ADC(ADC, ADC_CH, ADC_CH_MUXPOS);
 Pass in the ADC you want to use. channel, and the Pin you want to sue for POS side(NEG is gnd here)
+Used to convert Analog signals to digital signals for processing. (i.e. - current sensing)
 
     ADC can be setup in multiple ways- first divide being between single or differential mode
     In the example, it is setup in differential mode W gain.
@@ -21,7 +32,9 @@ Pass in the ADC you want to use. channel, and the Pin you want to sue for POS si
     
     ADC Channel
     
-    CTRL- channel input mode(DIFFWGAIN in this case) and the gain value
+    CTRL- channel input mode(DIFFWGAIN in this case) and the gain value, and to start a scan(1<<7)
+    remember to check if scan is done being computed before doing again. Value 1<<7 is turned off 
+    when scan is done
     MUXCTRL - setting the positive and negative pins.
 
 
@@ -74,20 +87,89 @@ Setup mininum and maximum outputs, with integral portion not allowed to go over
 the MAX& MIN Outs. Since the derivative portion can be quite noisy run at a very
 fast frequency, a low pass filter is automatically applied to the D value,
 with K being a constant used to change the low pass filter's response time. See 
-low pass filter for details on that.
+low pass filter for details on that. dt is the period of each loop.(1second /frequency)
+
+    crunch(input) logic
+    current error = setpoint - current value<<<<<< this is changed if it is CONT. If CONT, find
+    the shortest distance to setpoint is the current error.
+    total error+= current error;
+    derivate error = filter(current error - previous error)
+    output = P* current error + I* total Error + D* derivative error
+    
+    onTarget() logic
+    if on target according to acceptable range for more than a 
+    certain amount of time, return true
+
+    setAcceptableRange() logic
+    set the acceptable range +- where range is sepoint+-acceptable range
+    
+    setSetpoint()
+
+Current Control(P, I, dt, MAX&MIN IN&OUT)
+Basic PI loop. I is used much more than normal, P being used for the initial ramp up.
+Same setup as PID loop, but without the derivative term
+
+    crunch(input) logic
+    current error = setpoint - current value
+    the shortest distance to setpoint is the current error.
+    total error+= current error;
+    output = P* current error + I* total Error 
     
+    onTarget() logic
+    if on target according to acceptable range for more than a 
+    certain amount of time, return true
 
+    setAcceptableRange() logic
+    set the acceptable range +- where range is sepoint+-acceptable range
     
+    setSetpoint()
 
+Encoder w/ interrupts/ATKEncoder
+Encoders that automatically update based on interrupts running on a certain port.
+
+    PORTX_DIRSET &= ~(PINx_bm | PINy_bm) - set the direction of the two input pins
+    PORTX.INTCTRL - set the level of the interrupt(high/med/low)
+    PORTX.INTzMASK= set the interrupt of the port towards a certain pin
+    PORTX.PINxCTRL = set Pin to trigger on rising or falling edge 
+    (make sure one interrupt is set on falling and other on rising edge)
+    
+    ISR(PORTX_INTz_vect) logic ( 1 for each pin used)
+    if pins are different values, add to counter value, if pins are the same, subtract
+    This is due to the nature of encoders and how they count. If running clockwise,
+    the values line up, and if counter clockwise they dont line up(the values are 90 degrees away
+    from each other)
+    
+
+
+Basic Pin I/O
+    PORTX_DIRSET - set the direction of each port- 0 for input 1 for output
+    PORTX_DIRTGL - toggle direction 
+    PORTX_DIRSET/CLR - set or clear direction of each port
+    
+    PORTX_OUTSET/TGL/CLR- set/toggle/clear output to high or low
     
-Current Control
-Encoder w/ interrupts
-Pins
 clock frequency setup
-low pass filters
+Don't really understand this, just copy paste. Used to set clock to 48 Mhz
+
+	 OSC.XOSCCTRL = OSC_XOSCSEL_XTAL_256CLK_gc | OSC_FRQRANGE_12TO16_gc; // select external source
+	 OSC.CTRL = OSC_XOSCEN_bm; // enable external source
+	 while(!(OSC.STATUS & OSC_XOSCRDY_bm)); // wait for external
+	 OSC.PLLCTRL = OSC_PLLSRC_XOSC_gc | OSC_PLLFAC0_bm | OSC_PLLFAC1_bm; // select external osc for pll, do pll = source * 3
+	 //OSC.PLLCTRL = OSC_PLLSRC_XOSC_gc | OSC_PLLFAC1_bm; // pll = source * 2 for 32MHz std clock
+	 OSC.CTRL |= OSC_PLLEN_bm; // enable PLL
+	 while (!(OSC.STATUS & OSC_PLLRDY_bm)); // wait for PLL to be ready
+	 CCP = CCP_IOREG_gc; // enable protected register change
+	 CLK.CTRL = CLK_SCLKSEL_PLL_gc; // switch to PLL for main clock
+ 
  
 
+low pass filters(K)
+Used to clean a noisy signal. meant to be run at a fast frequency, since (1-2^-k)takes many
+clock counts to settle.
+Algorithm- output = y(n) = (1-2^-k)(y(n-1)) + (2^-k)(x(n)) << y(n) output, x(n)new input, n current clock count
 
+    filter(input)
+    give in new input, and returns in output