klipper-dgus/klippy/extras/spi_temperature.py

342 lines
12 KiB
Python

# Support for common SPI based thermocouple and RTD temperature sensors
#
# Copyright (C) 2018 Petri Honkala <cruwaller@gmail.com>
# Copyright (C) 2018 Kevin O'Connor <kevin@koconnor.net>
#
# This file may be distributed under the terms of the GNU GPLv3 license.
import math
import bus
######################################################################
# SensorBase
######################################################################
REPORT_TIME = 0.300
class SensorBase:
def __init__(self, config, chip_type, config_cmd=None, spi_mode=1):
self.printer = config.get_printer()
self.chip_type = chip_type
self._callback = None
self.min_sample_value = self.max_sample_value = 0
self._report_clock = 0
self.spi = bus.MCU_SPI_from_config(
config, spi_mode, pin_option="sensor_pin", default_speed=4000000)
if config_cmd is not None:
self.spi.spi_send(config_cmd)
self.mcu = mcu = self.spi.get_mcu()
# Reader chip configuration
self.oid = oid = mcu.create_oid()
mcu.register_response(self._handle_spi_response,
"thermocouple_result", oid)
mcu.register_config_callback(self._build_config)
def setup_minmax(self, min_temp, max_temp):
adc_range = [self.calc_adc(min_temp), self.calc_adc(max_temp)]
self.min_sample_value = min(adc_range)
self.max_sample_value = max(adc_range)
def setup_callback(self, cb):
self._callback = cb
def get_report_time_delta(self):
return REPORT_TIME
def _build_config(self):
self.mcu.add_config_cmd(
"config_thermocouple oid=%u spi_oid=%u thermocouple_type=%s" % (
self.oid, self.spi.get_oid(), self.chip_type))
clock = self.mcu.get_query_slot(self.oid)
self._report_clock = self.mcu.seconds_to_clock(REPORT_TIME)
self.mcu.add_config_cmd(
"query_thermocouple oid=%u clock=%u rest_ticks=%u"
" min_value=%u max_value=%u" % (
self.oid, clock, self._report_clock,
self.min_sample_value, self.max_sample_value), is_init=True)
def _handle_spi_response(self, params):
temp = self.calc_temp(params['value'], params['fault'])
next_clock = self.mcu.clock32_to_clock64(params['next_clock'])
last_read_clock = next_clock - self._report_clock
last_read_time = self.mcu.clock_to_print_time(last_read_clock)
self._callback(last_read_time, temp)
def fault(self, msg):
self.printer.invoke_async_shutdown(msg)
######################################################################
# MAX31856 thermocouple
######################################################################
MAX31856_CR0_REG = 0x00
MAX31856_CR0_AUTOCONVERT = 0x80
MAX31856_CR0_1SHOT = 0x40
MAX31856_CR0_OCFAULT1 = 0x20
MAX31856_CR0_OCFAULT0 = 0x10
MAX31856_CR0_CJ = 0x08
MAX31856_CR0_FAULT = 0x04
MAX31856_CR0_FAULTCLR = 0x02
MAX31856_CR0_FILT50HZ = 0x01
MAX31856_CR0_FILT60HZ = 0x00
MAX31856_CR1_REG = 0x01
MAX31856_CR1_AVGSEL1 = 0x00
MAX31856_CR1_AVGSEL2 = 0x10
MAX31856_CR1_AVGSEL4 = 0x20
MAX31856_CR1_AVGSEL8 = 0x30
MAX31856_CR1_AVGSEL16 = 0x70
MAX31856_MASK_REG = 0x02
MAX31856_MASK_COLD_JUNCTION_HIGH_FAULT = 0x20
MAX31856_MASK_COLD_JUNCTION_LOW_FAULT = 0x10
MAX31856_MASK_THERMOCOUPLE_HIGH_FAULT = 0x08
MAX31856_MASK_THERMOCOUPLE_LOW_FAULT = 0x04
MAX31856_MASK_VOLTAGE_UNDER_OVER_FAULT = 0x02
MAX31856_MASK_THERMOCOUPLE_OPEN_FAULT = 0x01
MAX31856_CJHF_REG = 0x03
MAX31856_CJLF_REG = 0x04
MAX31856_LTHFTH_REG = 0x05
MAX31856_LTHFTL_REG = 0x06
MAX31856_LTLFTH_REG = 0x07
MAX31856_LTLFTL_REG = 0x08
MAX31856_CJTO_REG = 0x09
MAX31856_CJTH_REG = 0x0A
MAX31856_CJTL_REG = 0x0B
MAX31856_LTCBH_REG = 0x0C
MAX31856_LTCBM_REG = 0x0D
MAX31856_LTCBL_REG = 0x0E
MAX31856_SR_REG = 0x0F
MAX31856_FAULT_CJRANGE = 0x80 # Cold Junction out of range
MAX31856_FAULT_TCRANGE = 0x40 # Thermocouple out of range
MAX31856_FAULT_CJHIGH = 0x20 # Cold Junction High
MAX31856_FAULT_CJLOW = 0x10 # Cold Junction Low
MAX31856_FAULT_TCHIGH = 0x08 # Thermocouple Low
MAX31856_FAULT_TCLOW = 0x04 # Thermocouple Low
MAX31856_FAULT_OVUV = 0x02 # Under Over Voltage
MAX31856_FAULT_OPEN = 0x01
MAX31856_SCALE = 5
MAX31856_MULT = 0.0078125
class MAX31856(SensorBase):
def __init__(self, config):
SensorBase.__init__(self, config, "MAX31856",
self.build_spi_init(config))
def calc_temp(self, adc, fault):
if fault & MAX31856_FAULT_CJRANGE:
self.fault("Max31856: Cold Junction Range Fault")
if fault & MAX31856_FAULT_TCRANGE:
self.fault("Max31856: Thermocouple Range Fault")
if fault & MAX31856_FAULT_CJHIGH:
self.fault("Max31856: Cold Junction High Fault")
if fault & MAX31856_FAULT_CJLOW:
self.fault("Max31856: Cold Junction Low Fault")
if fault & MAX31856_FAULT_TCHIGH:
self.fault("Max31856: Thermocouple High Fault")
if fault & MAX31856_FAULT_TCLOW:
self.fault("Max31856: Thermocouple Low Fault")
if fault & MAX31856_FAULT_OVUV:
self.fault("Max31856: Over/Under Voltage Fault")
if fault & MAX31856_FAULT_OPEN:
self.fault("Max31856: Thermocouple Open Fault")
adc = adc >> MAX31856_SCALE
# Fix sign bit:
if adc & 0x40000:
adc = ((adc & 0x3FFFF) + 1) * -1
temp = MAX31856_MULT * adc
return temp
def calc_adc(self, temp):
adc = int( ( temp / MAX31856_MULT ) + 0.5 ) # convert to ADC value
adc = adc << MAX31856_SCALE
return adc
def build_spi_init(self, config):
cmds = []
value = MAX31856_CR0_AUTOCONVERT
if config.getboolean('tc_use_50Hz_filter', False):
value |= MAX31856_CR0_FILT50HZ
cmds.append(0x80 + MAX31856_CR0_REG)
cmds.append(value)
types = {
"B" : 0b0000,
"E" : 0b0001,
"J" : 0b0010,
"K" : 0b0011,
"N" : 0b0100,
"R" : 0b0101,
"S" : 0b0110,
"T" : 0b0111,
}
value = config.getchoice('tc_type', types, default="K")
averages = {
"1" : MAX31856_CR1_AVGSEL1,
"2" : MAX31856_CR1_AVGSEL2,
"4" : MAX31856_CR1_AVGSEL4,
"8" : MAX31856_CR1_AVGSEL8,
"16" : MAX31856_CR1_AVGSEL16
}
value |= config.getchoice('tc_averaging_count', averages, "1")
cmds.append(0x80 + MAX31856_CR1_REG)
cmds.append(value)
value = (MAX31856_MASK_VOLTAGE_UNDER_OVER_FAULT |
MAX31856_MASK_THERMOCOUPLE_OPEN_FAULT)
cmds.append(0x80 + MAX31856_MASK_REG)
cmds.append(value)
return cmds
######################################################################
# MAX31855 thermocouple
######################################################################
MAX31855_SCALE = 18
MAX31855_MULT = 0.25
class MAX31855(SensorBase):
def __init__(self, config):
SensorBase.__init__(self, config, "MAX31855", spi_mode=0)
def calc_temp(self, adc, fault):
if adc & 0x1:
self.fault("MAX31855 : Open Circuit")
if adc & 0x2:
self.fault("MAX31855 : Short to GND")
if adc & 0x4:
self.fault("MAX31855 : Short to Vcc")
adc = adc >> MAX31855_SCALE
# Fix sign bit:
if adc & 0x2000:
adc = ((adc & 0x1FFF) + 1) * -1
temp = MAX31855_MULT * adc
return temp
def calc_adc(self, temp):
adc = int( ( temp / MAX31855_MULT ) + 0.5 ) # convert to ADC value
adc = adc << MAX31855_SCALE
return adc
######################################################################
# MAX6675 thermocouple
######################################################################
MAX6675_SCALE = 3
MAX6675_MULT = 0.25
class MAX6675(SensorBase):
def __init__(self, config):
SensorBase.__init__(self, config, "MAX6675", spi_mode=0)
def calc_temp(self, adc, fault):
if adc & 0x02:
self.fault("Max6675 : Device ID error")
if adc & 0x04:
self.fault("Max6675 : Thermocouple Open Fault")
adc = adc >> MAX6675_SCALE
# Fix sign bit:
if adc & 0x2000:
adc = ((adc & 0x1FFF) + 1) * -1
temp = MAX6675_MULT * adc
return temp
def calc_adc(self, temp):
adc = int( ( temp / MAX6675_MULT ) + 0.5 ) # convert to ADC value
adc = adc << MAX6675_SCALE
return adc
######################################################################
# MAX31865 (RTD sensor)
######################################################################
MAX31865_CONFIG_REG = 0x00
MAX31865_RTDMSB_REG = 0x01
MAX31865_RTDLSB_REG = 0x02
MAX31865_HFAULTMSB_REG = 0x03
MAX31865_HFAULTLSB_REG = 0x04
MAX31865_LFAULTMSB_REG = 0x05
MAX31865_LFAULTLSB_REG = 0x06
MAX31865_FAULTSTAT_REG = 0x07
MAX31865_CONFIG_BIAS = 0x80
MAX31865_CONFIG_MODEAUTO = 0x40
MAX31865_CONFIG_1SHOT = 0x20
MAX31865_CONFIG_3WIRE = 0x10
MAX31865_CONFIG_FAULTCLEAR = 0x02
MAX31865_CONFIG_FILT50HZ = 0x01
MAX31865_FAULT_HIGHTHRESH = 0x80
MAX31865_FAULT_LOWTHRESH = 0x40
MAX31865_FAULT_REFINLOW = 0x20
MAX31865_FAULT_REFINHIGH = 0x10
MAX31865_FAULT_RTDINLOW = 0x08
MAX31865_FAULT_OVUV = 0x04
VAL_A = 0.00390830
VAL_B = 0.0000005775
VAL_C = -0.00000000000418301
VAL_ADC_MAX = 32768.0 # 2^15
class MAX31865(SensorBase):
def __init__(self, config):
self.rtd_nominal_r = config.getint('rtd_nominal_r', 100)
self.reference_r = config.getfloat('rtd_reference_r', 430., above=0.)
SensorBase.__init__(self, config, "MAX31865",
self.build_spi_init(config))
def calc_temp(self, adc, fault):
if fault & 0x80:
self.fault("Max31865 RTD input is disconnected")
if fault & 0x40:
self.fault("Max31865 RTD input is shorted")
if fault & 0x20:
self.fault(
"Max31865 VREF- is greater than 0.85 * VBIAS, FORCE- open")
if fault & 0x10:
self.fault("Max31865 VREF- is less than 0.85 * VBIAS, FORCE- open")
if fault & 0x08:
self.fault("Max31865 VRTD- is less than 0.85 * VBIAS, FORCE- open")
if fault & 0x04:
self.fault("Max31865 Overvoltage or undervoltage fault")
if fault & 0x03:
self.fault("Max31865 Unspecified error")
adc = adc >> 1 # remove fault bit
R_rtd = (self.reference_r * adc) / VAL_ADC_MAX
temp = ((( ( -1 * self.rtd_nominal_r ) * VAL_A )
+ math.sqrt( ( self.rtd_nominal_r**2 * VAL_A * VAL_A )
- ( 4 * self.rtd_nominal_r * VAL_B
* ( self.rtd_nominal_r - R_rtd ) )))
/ (2 * self.rtd_nominal_r * VAL_B))
return temp
def calc_adc(self, temp):
R_rtd = temp * ( 2 * self.rtd_nominal_r * VAL_B )
R_rtd = math.pow( ( R_rtd + ( self.rtd_nominal_r * VAL_A ) ), 2)
R_rtd = -1 * ( R_rtd - (self.rtd_nominal_r**2 * VAL_A * VAL_A ) )
R_rtd = R_rtd / ( 4 * self.rtd_nominal_r * VAL_B )
R_rtd = ( -1 * R_rtd ) + self.rtd_nominal_r
adc = int( ( ( R_rtd * VAL_ADC_MAX ) / self.reference_r) + 0.5 )
adc = adc << 1 # Add fault bit
return adc
def build_spi_init(self, config):
value = (MAX31865_CONFIG_BIAS |
MAX31865_CONFIG_MODEAUTO |
MAX31865_CONFIG_FAULTCLEAR)
if config.getboolean('rtd_use_50Hz_filter', False):
value |= MAX31865_CONFIG_FILT50HZ
if config.getint('rtd_num_of_wires', 2) == 3:
value |= MAX31865_CONFIG_3WIRE
cmd = 0x80 + MAX31865_CONFIG_REG
return [cmd, value]
######################################################################
# Sensor registration
######################################################################
Sensors = {
"MAX6675": MAX6675,
"MAX31855": MAX31855,
"MAX31856": MAX31856,
"MAX31865": MAX31865,
}
def load_config(config):
# Register sensors
pheater = config.get_printer().lookup_object("heater")
for name, klass in Sensors.items():
pheater.add_sensor_factory(name, klass)