# Copyright (c) 2016, NECST Laboratory, Politecnico di Milano
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from math import ceil
from . import Pmod
from . import PMOD_GROVE_G3
from . import PMOD_GROVE_G4
from . import MAILBOX_OFFSET
__author__ = "Marco Rabozzi, Luca Cerina, Giuseppe Natale"
__copyright__ = "Copyright 2016, NECST Laboratory, Politecnico di Milano"
PMOD_GROVE_FINGER_HR_PROGRAM = "pmod_grove_finger_hr.bin"
GROVE_FINGER_HR_LOG_START = MAILBOX_OFFSET+16
GROVE_FINGER_HR_LOG_END = GROVE_FINGER_HR_LOG_START+(1000*4)
CONFIG_IOP_SWITCH = 0x1
READ_DATA = 0x2
READ_AND_LOG_DATA = 0x3
STOP_LOG = 0xC
[docs]class Grove_FingerHR(object):
"""This class controls the Grove finger clip heart rate sensor.
Grove Finger sensor based on the TCS3414CS.
Hardware version: v1.3.
Attributes
----------
microblaze : Pmod
Microblaze processor instance used by this module.
log_running : int
The state of the log (0: stopped, 1: started).
log_interval_ms : int
Time in milliseconds between sampled reads.
"""
def __init__(self, mb_info, gr_pin):
"""Return a new instance of an Grove_FingerHR object.
Parameters
----------
mb_info : dict
A dictionary storing Microblaze information, such as the
IP name and the reset name.
gr_pin: list
A group of pins on pmod-grove adapter.
"""
if gr_pin not in [PMOD_GROVE_G3,
PMOD_GROVE_G4]:
raise ValueError("Group number can only be G3 - G4.")
self.microblaze = Pmod(mb_info, PMOD_GROVE_FINGER_HR_PROGRAM)
self.log_interval_ms = 1000
self.log_running = 0
self.microblaze.write_mailbox(0, gr_pin)
self.microblaze.write_blocking_command(CONFIG_IOP_SWITCH)
[docs] def read(self):
"""Read the heart rate value from the Grove Finger HR peripheral.
Returns
-------
int
An integer representing the heart rate frequency.
"""
self.microblaze.write_blocking_command(READ_DATA)
freq = self.microblaze.read_mailbox(0)
return freq
[docs] def start_log(self, log_interval_ms=100):
"""Start recording multiple heart rate values in a log.
This method will first call set the log interval before writing to
the MMIO.
Parameters
----------
log_interval_ms : int
The time between two samples in milliseconds.
Returns
-------
None
"""
if log_interval_ms < 0:
raise ValueError("Time between samples cannot be less than zero.")
self.log_running = 1
self.log_interval_ms = log_interval_ms
self.microblaze.write_mailbox(0x4, log_interval_ms)
self.microblaze.write_non_blocking_command(READ_AND_LOG_DATA)
[docs] def stop_log(self):
"""Stop recording the values in the log.
Simply write 0xC to the MMIO to stop the log.
Returns
-------
None
"""
if self.log_running == 1:
self.microblaze.write_non_blocking_command(STOP_LOG)
self.log_running = 0
else:
raise RuntimeError("No grove finger HR log running.")
[docs] def get_log(self):
"""Return list of logged samples.
Returns
-------
list
List of integers containing the heart rate.
"""
# Stop logging
self.stop_log()
# Prep iterators and results list
[head_ptr, tail_ptr] = self.microblaze.read_mailbox(0x8, 2)
readings = list()
# Sweep circular buffer for samples
if head_ptr == tail_ptr:
return None
elif head_ptr < tail_ptr:
num_words = int(ceil((tail_ptr - head_ptr) / 4))
data = self.microblaze.read(head_ptr, num_words)
readings += data
else:
num_words = int(ceil((GROVE_FINGER_HR_LOG_END - head_ptr) / 4))
data = self.microblaze.read(head_ptr, num_words)
readings += data
num_words = int(ceil((tail_ptr - GROVE_FINGER_HR_LOG_START) / 4))
data = self.microblaze.read(GROVE_FINGER_HR_LOG_START, num_words)
readings += data
return readings