Add image of wiring for AC excitation. Add v2 develop software

software/ac_exc/BRIDGEADC01.py

@@ -0,0 +1,167 @@
+class BRIDGEADC01:
+    """
+    Driver for the AD7730/AD7730L bridge ADC device. 
+    """
+
+    def __init__(self,spi, SPI_CS):
+
+        self.spi=spi
+        self.CS = SPI_CS
+        #AD7730 register address
+        self.AD7730_COMM_REG            =0b000
+        self.AD7730_STATUS_REG          =0b000
+        self.AD7730_DATA_REG            =0b001
+        self.AD7730_MODE_REG            =0b010
+        self.AD7730_FILTER_REG          =0b011
+        self.AD7730_DAC_REG             =0b100
+        self.AD7730_OFFSET_REG          =0b101
+        self.AD7730_GAIN_REG            =0b110
+        self.AD7730_TEST_REG            =0b111      # do not change state of this register
+
+        self.AD7730_IDLE_MODE           =0b000
+        self.AD7730_CCONVERSION_MODE    =0b001
+        self.AD7730_SCONVERSION_MODE    =0b010
+        self.AD7730_POWERDOWN_MODE      =0b011
+        self.AD7730_INT_ZERO_CALIBRATION=0b100
+        self.AD7730_INT_FULL_CALIBRATION=0b101
+        self.AD7730_SYSTEM_ZERO_CALIBRATION=0b110
+        self.AD7730_SYSTEM_FULL_CALIBRATION=0b111
+
+        self.AD7730_BIIPOLAR_MODE        =0b0
+        self.AD7730_UNIPOLAR_MODE       =0b1
+        self.AD7730_IOENABLE_MODE       =0b1
+        self.AD7730_IODISABLE_MODE      =0b0
+        self.AD7730_16bitDATA_MODE      =0b0
+        self.AD7730_24bitDATA_MODE      =0b1
+        self.AD7730_REFERENCE_2V5       =0b0        
+        self.AD7730_REFERENCE_5V        =0b1
+        self.AD7730_10mVIR_MODE         =0b00
+        self.AD7730_20mVIR_MODE         =0b01
+        self.AD7730_40mVIR_MODE         =0b10
+        self.AD7730_80mVIR_MODE         =0b11
+        self.AD7730_MCLK_ENABLE_MODE    =0b0
+        self.AD7730_MCLK_DISABLE_MODE   =0b1
+        self.AD7730_BURNOUT_DISABLE     =0b0
+        self.AD7730_BURNOUT_ENABLE      =0b1
+        self.AD7730_AIN1P_AIN1N         =0b00
+        self.AD7730_AIN2P_AIN2N         =0b01
+        self.AD7730_AIN1N_AIN1N         =0b10
+        self.AD7730_AIN1N_AIN2N         =0b11      
+
+    def reset(self):
+        self.spi.SPI_write(self.CS, [0xFF])       # wrinting least 32 serial clock with 1 at data input resets the device. 
+        self.spi.SPI_write(self.CS, [0xFF])
+        self.spi.SPI_write(self.CS, [0xFF])
+        self.spi.SPI_write(self.CS, [0xFF])
+
+    def single_write(self, register, value):
+        comm_reg = (0b00000 << 3) + register
+        self.spi.SPI_write(self.CS, [comm_reg] + value)
+
+    def single_read(self, register):
+        '''
+        Reads data from desired register only once. 
+        '''
+
+        comm_reg = (0b00010 << 3) + register
+
+        if register == self.AD7730_STATUS_REG:
+            bytes_num = 1
+        elif register == self.AD7730_DATA_REG:
+            bytes_num = 3
+        elif register == self.AD7730_MODE_REG:
+            bytes_num = 2
+        elif register == self.AD7730_FILTER_REG:
+            bytes_num = 3
+        elif register == self.AD7730_DAC_REG:
+            bytes_num = 1
+        elif register == self.AD7730_OFFSET_REG:
+            bytes_num = 3
+        elif register == self.AD7730_GAIN_REG:
+            bytes_num = 3
+        elif register == self.AD7730_TEST_REG:
+            bytes_num = 3
+
+        command = [comm_reg] + ([0x00] * bytes_num)
+        self.spi.SPI_write(self.CS, command)
+        data = self.spi.SPI_read(bytes_num + 1)        
+        return data[1:]
+
+    def getStatus(self):
+
+        """
+        RDY - Ready Bit. This bit provides the status of the RDY flag from the part. The status and function of this bit is the same as the RDY output pin. A number of events set the RDY bit high as indicated in Table XVIII in datasheet
+
+        STDY - Steady Bit. This bit is updated when the filter writes a result to the Data Register. If the filter is
+        in FASTStep mode (see Filter Register section) and responding to a step input, the STDY bit
+        remains high as the initial conversion results become available. The RDY output and bit are set
+        low on these initial conversions to indicate that a result is available. If the STDY is high, however,
+        it indicates that the result being provided is not from a fully settled second-stage FIR filter. When the
+        FIR filter has fully settled, the STDY bit will go low coincident with RDY. If the part is never placed
+        into its FASTStep mode, the STDY bit will go low at the first Data Register read and it is
+        not cleared by subsequent Data Register reads. A number of events set the STDY bit high as indicated in Table XVIII. STDY is set high along with RDY by all events in the table except a Data Register read.
+
+        STBY - Standby Bit. This bit indicates whether the AD7730 is in its Standby Mode or normal mode of
+        operation. The part can be placed in its standby mode using the STANDBY input pin or by
+        writing 011 to the MD2 to MD0 bits of the Mode Register. The power-on/reset status of this bit
+        is 0 assuming the STANDBY pin is high.
+
+
+
+
+
+        NOREF - No Reference Bit. If the voltage between the REF IN(+) and REF IN(-) pins is below 0.3 V, or either of these inputs is open-circuit, the NOREF bit goes to 1. If NOREF is active on completion of a conversion, the Data Register is loaded with all 1s. If NOREF is active on completion of a calibration, updating of the calibration registers is inhibited."""
+
+        status = self.single_read(self.AD7730_STATUS_REG)
+        bits_values = dict([('NOREF',status[0] & 0x10 == 0x10),
+                            ('STBY',status[0] & 0x20 == 0x20),
+                            ('STDY',status[0] & 0x40 == 0x40),
+                            ('RDY',status[0] & 0x80 == 0x80)])
+        return bits_values
+
+    def getData(self):
+        data = self.single_read(self.AD7730_DATA_REG)
+        value = (data[0] << 15) + (data[1] << 7) + data[2]
+        return value
+
+    def IsBusy(self):
+        """ Return True if ADC is busy """
+        status = self.getStatus()
+        return status['RDY']
+
+
+    def setMode(self
+                    ,mode  
+                    ,polarity 
+                    ,den 
+                    ,iovalue 
+                    ,data_length 
+                    ,reference 
+                    ,input_range 
+                    ,clock_enable 
+                    ,burn_out 
+                    ,channel):
+        '''
+        def setMode(self
+                    ,mode = self.AD7730_IDLE_MODE 
+                    ,polarity = self.AD7730_UNIPOLAR_MODE
+                    ,den = self.AD7730_IODISABLE_MODE
+                    ,iovalue = 0b00
+                    ,data_lenght = self.AD7730_24bitDATA_MODE
+                    ,reference = self.AD7730_REFERENCE_5V
+                    ,input_range = self.AD7730_40mVIR_MODE
+                    ,clock_enable = self.AD7730_MCLK_ENABLE_MODE
+                    ,burn_out = self.AD7730_BURNOUT_DISABLE
+                    ,channel = self.AD7730_AIN1P_AIN1N
+               ):
+        '''
+        mode_MSB = (mode << 5) + (polarity << 4) + (den << 3) + (iovalue << 1) + data_length
+        mode_LSB = (reference << 7) + (0b0 << 6) + (input_range << 4) + (clock_enable << 3) + (burn_out << 2) + channel
+
+        self.single_write(self.AD7730_MODE_REG, [mode_MSB, mode_LSB])
+
+    def setFilter(self):
+        data = self.single_read(self.AD7730_FILTER_REG)
+        data[2] = data[2] | 0b00110011
+        self.single_write(self.AD7730_FILTER_REG, data)
+        return data

software/ac_exc/I2CSPI_BRIDGEADC01_simple.py

@@ -0,0 +1,175 @@
+#!/usr/bin/python
+
+#uncomment for debbug purposes
+#import logging
+#logging.basicConfig(level=logging.DEBUG) 
+
+import sys
+import time
+from pymlab import config
+import logging
+
+from BRIDGEADC01 import BRIDGEADC01
+
+"""
+Show data from BRIDGEADC01 module. 
+"""
+
+##from vispy import app, scene, color
+
+import numpy as np
+
+LOGGER = logging.getLogger(__name__)
+
+
+
+
+
+
+"""canvas = scene.SceneCanvas(keys='interactive', show=True, size=(1024, 768))
+grid = canvas.central_widget.add_grid()
+view = grid.add_view(0, 1)
+view.camera = scene.MagnifyCamera(mag=1, size_factor=0.5, radius_ratio=0.6)
+
+# Add axes
+yax = scene.AxisWidget(orientation='left')
+yax.stretch = (0.05, 1)
+grid.add_widget(yax, 0, 0)
+yax.link_view(view)
+
+xax = scene.AxisWidget(orientation='bottom')
+xax.stretch = (1, 0.05)
+grid.add_widget(xax, 1, 1)
+xax.link_view(view)
+
+
+N = 4
+M = 1000
+
+view.camera.rect = (0, 526200, 1, 500)
+
+lines = scene.ScrollingLines(n_lines=N, line_size=M, columns=1, dx=0.8/M, #color = 'red',
+                             cell_size=(1, 8), parent=view.scene)
+lines.transform = scene.STTransform(scale=(1, 1/8.))
+
+"""
+
+cfg = config.Config(
+    i2c = {
+        "port": 9,
+    },
+
+    bus = [
+        { "name":"spi", "type":"i2cspi", "address": 0x28},
+    ],
+)
+
+cfg.initialize()
+
+print "SPI weight scale sensor with SPI interface. The interface is connected to the I2CSPI module which translates signalls. \r\n"
+
+spi = cfg.get_device("spi")
+
+try:
+    print "SPI configuration.."
+    spi.SPI_config(spi.I2CSPI_MSB_FIRST| spi.I2CSPI_MODE_CLK_IDLE_LOW_DATA_EDGE_LEADING| spi.I2CSPI_CLK_461kHz)
+    spi.GPIO_config(spi.I2CSPI_SS2 | spi.I2CSPI_SS3, spi.SS2_INPUT | spi.SS3_INPUT)
+
+    print "Weight scale configuration.."
+    scale = BRIDGEADC01(spi,spi.I2CSPI_SS0)
+
+    scale.reset()
+
+    scale.setFilter()
+
+    scale.setMode(
+                     mode = scale.AD7730_SYSTEM_ZERO_CALIBRATION
+                    ,polarity = scale.AD7730_BIIPOLAR_MODE
+                    ,den = scale.AD7730_IODISABLE_MODE
+                    ,iovalue = 0b00
+                    ,data_length = scale.AD7730_24bitDATA_MODE
+                    ,reference = scale.AD7730_REFERENCE_5V
+                    ,input_range = scale.AD7730_80mVIR_MODE
+                    ,clock_enable = scale.AD7730_MCLK_ENABLE_MODE
+                    ,burn_out = scale.AD7730_BURNOUT_DISABLE
+                    ,channel = scale.AD7730_AIN1P_AIN1N
+                )
+
+    while scale.IsBusy():            ## wait for RDY pin to go low to indicate end of callibration cycle. 
+        print scale.getStatus()
+        time.sleep(0.1)
+
+    print "system Zero scale calibration completed.."
+
+
+
+    scale.setMode(
+                     mode = scale.AD7730_INT_FULL_CALIBRATION
+                    ,polarity = scale.AD7730_BIIPOLAR_MODE
+                    ,den = scale.AD7730_IODISABLE_MODE
+                    ,iovalue = 0b00
+                    ,data_length = scale.AD7730_24bitDATA_MODE
+                    ,reference = scale.AD7730_REFERENCE_5V
+                    ,input_range = scale.AD7730_80mVIR_MODE
+                    ,clock_enable = scale.AD7730_MCLK_ENABLE_MODE
+                    ,burn_out = scale.AD7730_BURNOUT_DISABLE
+                    ,channel = scale.AD7730_AIN1P_AIN1N
+				)
+    print "Internal Full scale calibration started"
+
+    while scale.IsBusy():            ## wait for RDY pin to go low to indicate end of callibration cycle. 
+        print scale.single_read(scale.AD7730_MODE_REG)
+        time.sleep(0.1)
+
+    print "Full scale calibration completed. Start zero scale calibration"
+
+
+
+#    spi.SPI_write(spi.I2CSPI_SS0, [0x02, 0x91, 0x80])
+    scale.setMode(
+                     mode = scale.AD7730_SYSTEM_ZERO_CALIBRATION
+                    ,polarity = scale.AD7730_BIIPOLAR_MODE
+                    ,den = scale.AD7730_IODISABLE_MODE
+                    ,iovalue = 0b00
+                    ,data_length = scale.AD7730_24bitDATA_MODE
+                    ,reference = scale.AD7730_REFERENCE_5V
+                    ,input_range = scale.AD7730_80mVIR_MODE
+                    ,clock_enable = scale.AD7730_MCLK_ENABLE_MODE
+                    ,burn_out = scale.AD7730_BURNOUT_DISABLE
+                    ,channel = scale.AD7730_AIN1P_AIN1N
+                )
+
+    while scale.IsBusy():            ## wait for RDY pin to go low to indicate end of callibration cycle. 
+        print scale.getStatus()
+        time.sleep(0.1)
+
+    print "System Zero scale calibration completed.. Start reading the data.."
+
+    scale.setFilter()
+
+    while 1:
+
+        scale.setMode(
+                     mode = scale.AD7730_SCONVERSION_MODE
+                    ,polarity = scale.AD7730_BIIPOLAR_MODE
+                    ,den = scale.AD7730_IODISABLE_MODE
+                    ,iovalue = 0b00
+                    ,data_length = scale.AD7730_24bitDATA_MODE
+                    ,reference = scale.AD7730_REFERENCE_5V
+                    ,input_range = scale.AD7730_80mVIR_MODE
+                    ,clock_enable = scale.AD7730_MCLK_ENABLE_MODE
+                    ,burn_out = scale.AD7730_BURNOUT_DISABLE
+                    ,channel = scale.AD7730_AIN1P_AIN1N
+                )
+
+        while scale.IsBusy():            ## wait for RDY pin to go low to indicate end of callibration cycle. 
+            time.sleep(0.05)
+
+        channel1 = scale.getData()
+
+        data = np.array([channel1])
+        print data
+
+except KeyboardInterrupt:
+    sys.exit(0)
+