blink.nim

import msp430
import msp430usb
import unsigned

# Trivial blink demo for now.

# Button on P2_0, LED on PJ_3
type
  States = enum
    Blinking
    On
    Off

var state {.volatile.} : States

ISR:
  proc PORT2() =
    case P2IV
    of 2: 
      case state
      of Blinking: state = On
      of On: state = Off
      of Off: state = Blinking
    else: return

template toggleLED() =
  PJ.OUT = PJ.OUT xor 8u16

proc main =
  PJ.DIR[3] = 1
  PA.DIR[8] = 0
  PA.OUT[8] = 1
  PA.REN[8] = 1
  PA.IES[8] = 1
  PA.IE[8] = 1
  PA.IFG = 0
  usbinit()
  enable_interrupts()

  while true:
    case state
    of Blinking:
      toggleLED()
      #if ((PJ.OUT and 8)==0) != ((PA.IN and 256)==0):
      #  toggleLED()
      var i {.volatile.} = 0x7350  # volatile to keep delay loop
      while i!=0:
        i = i - 1
    of On:
      PJ.OUT[3] = 1
    of Off:
      PJ.OUT[3] = 0

#proc testvol =
#  PA.OUT = 5
#  PA.OUT = 5

main()
#testvol()


# My first project is a PC joystick to USB adapter based on an
# Olimexino-5510 board (a MSP430 board resembling an Arduino Pro).
# Judging by the SW/HW I2C solder jumpers on the board, the
# designer was unaware that this chip can remap those functions. 
# I intend to measure the analog resistances by timing a capacitor
# charge, similar to the original card. Luckily the f5510 has
# more than four timer capture pins for this.
# I also intend to add a Gravis Grip decoder, for which the
# pin change interrupts will come in handy. 
# Pins connected on adapter board so far:
# 1,8,9,15  5v
# 4,5,12   gnd
# 7  b2   d3   ta0_0
# 6  y1   d4   ta0_1   has capacitor
# 14 b3   d2   p1_0
# 13 y2   d5   ta0_2   has capacitor
# 11 x2   d6   ta0_3   has capacitor
# 3  x1   d7   ta0_4   has capacitor
# 2  b1   d8   p1_6
# 10 b4   d9   p1_7