Commit 3b72da67 authored by Damien George's avatar Damien George
Browse files

stmhal, STM32F4DISC: Small changes to ST accel driver.

parent 6cf8dd4f
......@@ -24,36 +24,38 @@ LIS302DL_WHO_AM_I_ADDR = const(0x0f)
LIS302DL_WHO_AM_I_VAL = const(0x3b)
LIS302DL_CTRL_REG1_ADDR = const(0x20)
LIS302DL_OUT_X = const(0x29)
LIS302DL_OUT_Y = const(0x2b)
LIS302DL_OUT_Z = const(0x2d)
# Configuration for 100Hz sampling rate, +-2g range
LIS302DL_CONF = 0b01000111
LIS302DL_CONF = const(0b01000111)
def signed8(x):
def convert_raw_to_g(x):
if x & 0x80:
return x - 256
else:
return x
x = x - 256
return x * 18 / 1000
class STAccel:
def __init__(self):
self.cs_pin = Pin('PE3', Pin.OUT_PP, Pin.PULL_NONE)
self.cs_pin.high()
self.spi = SPI(1, SPI.MASTER, baudrate=328125, polarity=0, phase=1, bits=8)
self.wr(LIS302DL_CTRL_REG1_ADDR, bytearray([LIS302DL_CONF]))
if self.read_id()[0] != LIS302DL_WHO_AM_I_VAL:
self.write_bytes(LIS302DL_CTRL_REG1_ADDR, bytearray([LIS302DL_CONF]))
if self.read_id() != LIS302DL_WHO_AM_I_VAL:
raise Exception('LIS302DL accelerometer not present')
def rd(self, addr, nbytes):
def read_bytes(self, addr, nbytes):
if nbytes > 1:
addr |= READWRITE_CMD | MULTIPLEBYTE_CMD
else:
addr |= READWRITE_CMD
self.cs_pin.low()
self.spi.send(addr)
buf = self.spi.send_recv(bytearray(nbytes * [0])) # read data, MSB first
#buf = self.spi.send_recv(bytearray(nbytes * [0])) # read data, MSB first
buf = self.spi.recv(nbytes)
self.cs_pin.high()
return buf
def wr(self, addr, buf):
def write_bytes(self, addr, buf):
if len(buf) > 1:
addr |= MULTIPLEBYTE_CMD
self.cs_pin.low()
......@@ -63,11 +65,19 @@ class STAccel:
self.cs_pin.high()
def read_id(self):
return self.rd(LIS302DL_WHO_AM_I_ADDR, 1)
return self.read_bytes(LIS302DL_WHO_AM_I_ADDR, 1)[0]
def get_xyz(self):
val = self.rd(LIS302DL_OUT_X, 5)
x = signed8(val[0]) * 18.0 / 1000
y = signed8(val[2]) * 18.0 / 1000
z = signed8(val[4]) * 18.0 / 1000
return [x, y, z]
def x(self):
return convert_raw_to_g(self.read_bytes(LIS302DL_OUT_X, 1)[0])
def y(self):
return convert_raw_to_g(self.read_bytes(LIS302DL_OUT_Y, 1)[0])
def z(self):
return convert_raw_to_g(self.read_bytes(LIS302DL_OUT_Z, 1)[0])
def xyz(self):
val = self.read_bytes(LIS302DL_OUT_X, 5)
return [convert_raw_to_g(val[0]),
convert_raw_to_g(val[2]),
convert_raw_to_g(val[4])]
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