bus_pirate.py

   1 #!/usr/bin/env python
   2 # -*- coding: iso-8859-15 -*-
   3
   4 import serial
   5 import struct
   6
   7
   8 # http://dangerousprototypes.com/docs/Bitbang
   9 # http://dangerousprototypes.com/docs/SPI_(binary)
  10 class BP:
  11         def __init__(self, sDevice):
  12                 self.pSerial = serial.Serial(sDevice, baudrate=115200, timeout=0.1)
  13                 self.mode_bit_bang()
  14
  15         def command(self, cmd, num_read):
  16                 self.pSerial.write(cmd)
  17                 return self.pSerial.read(num_read)
  18
  19         def mode_bit_bang(self):
  20                 for i in range(20):
  21                         if self.command(chr(0x0), 5) == "BBIO1":
  22                                 return
  23                 raise Exception()
  24
  25         def mode_spi(self, mode, speed):
  26                 if self.command(chr(0x1), 4) != "SPI1":
  27                         raise Exception()
  28                 self.spi_set_mode(mode)
  29                 self.spi_set_speed(speed)
  30
  31         def spi_set_mode(self, mode):
  32                 if mode not in range(0, 4):
  33                         raise Exception("Unknown mode")
  34                 if mode == 0:
  35                         self.spi_command(chr(0b10001000))
  36                 elif mode == 1:
  37                         self.spi_command(chr(0b10001010))
  38                 elif mode == 2:
  39                         self.spi_command(chr(0b10001100))
  40                 elif mode == 3:
  41                         self.spi_command(chr(0b10001110))
  42
  43
  44         def spi_set_speed(self, speed):
  45                 lSpeeds = ["30kHz", "125kHz", "250kHz", "1MHz", "2MHz", "2.6MHz", "4MHz", "8MHz"]
  46                 val = lSpeeds.index(speed)
  47                 self.spi_command(chr(0b01100000 | val))
  48
  49         def command_byte_set(self, bit):
  50                 enable = 1<<bit
  51                 state = ord(self.command(chr(0x80 | enable, 1)))
  52                 if not state & enable:
  53                         raise Exception("Got 0x%x, expected 0xc0" % state)
  54
  55         def power_enable(self):
  56                 self.command_byte_set(6)
  57
  58         def get_adc(self):
  59                 s = self.command(chr(0x14), 2)
  60                 v = struct.unpack(">h", s)
  61                 return v[0]/1024.0*6.6
  62
  63         def spi_command(self, cmd):
  64                 ret = self.command(cmd, 1)
  65                 if ord(ret) != 0x1:
  66                         raise Exception()
  67
  68         def spi_write(self, data, num_read=0):
  69                 if len(data) > 4096:
  70                         raise Exception("SPI Data String too long")
  71                 return self.spi_command(struct.pack(">Bhh%ds" % len(data), 0x04, len(data), num_read, data))