Merge branch 'master' of github.com:jamesbowman/i2cdriver

c/common/i2cdriver.c

@@ -18,7 +18,9 @@
 
 #if defined(WIN32)  // {
 
+#ifndef NOMINMAX
 #define NOMINMAX
+#endif
 #include <windows.h>
 
 void ErrorExit(const char *func_name) 
@@ -323,7 +325,7 @@ uint8_t i2c_reset(I2CDriver *sd)
 
 int i2c_start(I2CDriver *sd, uint8_t dev, uint8_t op)
 {
-  uint8_t start[2] = {'s', (dev << 1) | op};
+  uint8_t start[2] = {'s', (uint8_t)((dev << 1) | op)};
   writeToSerialPort(sd->port, start, sizeof(start));
   return i2c_ack(sd);
 }
@@ -367,6 +369,56 @@ void i2c_monitor(I2CDriver *sd, int enable)
   charCommand(sd, enable ? 'm' : '@');
 }
 
+void i2c_capture(I2CDriver *sd)
+{
+  printf("Capture started\n");
+  charCommand(sd, 'c');
+  uint8_t bytes[1];
+
+  int starting = 0;
+  int nbits = 0, bits = 0;
+  while (1) {
+    int i;
+    readFromSerialPort(sd->port, bytes, 1);
+    for (i = 0; i < 2; i++) {
+      int symbol = (i == 0) ? (bytes[0] >> 4) : (bytes[0] & 0xf);
+      switch (symbol) {
+        case 0:
+          break;
+        case 1:
+          starting = 1;
+          break;
+        case 2:
+          printf("STOP\n");
+          starting = 1;
+          break;
+        case 8:
+        case 9:
+        case 10:
+        case 11:
+        case 12:
+        case 13:
+        case 14:
+        case 15:
+          bits = (bits << 3) | (symbol & 7);
+          nbits += 3;
+          if (nbits == 9) {
+            int b8 = (bits >> 1), ack = !(bits & 1);
+            if (starting) {
+              starting = 0;
+              printf("START %02x %s", b8 >> 1, (b8 & 1) ? "READ" : "WRITE");
+            } else {
+              printf("BYTE %02x", b8);
+            }
+            printf(" %s\n", ack ? "ACK" : "NAK");
+            nbits = 0;
+            bits = 0;
+          }
+      }
+    }
+  }
+}
+
 int i2c_commands(I2CDriver *sd, int argc, char *argv[])
 {
   int i;
@@ -479,6 +531,12 @@ int i2c_commands(I2CDriver *sd, int argc, char *argv[])
       }
       break;
 
+    case 'c':
+      {
+        i2c_capture(sd);
+      }
+      break;
+
     default:
     badcommand:
       fprintf(stderr, "Bad command '%s'\n", token);
@@ -492,6 +550,7 @@ int i2c_commands(I2CDriver *sd, int argc, char *argv[])
       fprintf(stderr, "  p              send a STOP\n");
       fprintf(stderr, "  r dev N        read N bytes from I2C device dev, then STOP\n");
       fprintf(stderr, "  m              enter I2C bus monitor mode\n");
+      fprintf(stderr, "  c              enter I2C bus capture mode\n");
       fprintf(stderr, "\n");
 
       return 1;

c/common/i2cdriver.h

@@ -36,6 +36,7 @@ int  i2c_start(I2CDriver *sd, uint8_t dev, uint8_t op);
 void i2c_stop(I2CDriver *sd);
 
 void i2c_monitor(I2CDriver *sd, int enable);
+void i2c_capture(I2CDriver *sd);
 
 int i2c_commands(I2CDriver *sd, int argc, char *argv[]);
 

c/linux/Makefile.clang

@@ -0,0 +1,11 @@
+CC=clang
+CFLAGS += -I common -Wall -Wpointer-sign -xc++ -std=c++17 # -Werror
+
+all: build/i2ccl
+
+install: all
+	cp build/i2ccl /usr/local/bin
+
+build/i2ccl: linux/i2c.c common/i2cdriver.c
+	mkdir -p build/
+	$(CC) -o $@ $(CPPFLAGS) $(CFLAGS) $^

python/i2cdriver.py

@@ -68,7 +68,15 @@ class I2CDriver:
     """
     A connected I2CDriver.
 
-    :ivar product: product code e.g. 'i2cdriver1'
+    :param port: The USB port to connect to
+    :type port: str
+    :param reset: Issue an I2C bus reset on connection
+    :type reset: bool
+
+    After connection, the following object variables reflect the current values of the I2CDriver.
+    They are updated by calling :py:meth:`getstatus`.
+
+    :ivar product: product code e.g. 'i2cdriver1' or 'i2cdriverm'
     :ivar serial: serial string of I2CDriver
     :ivar uptime: time since I2CDriver boot, in seconds
     :ivar voltage: USB voltage, in V
@@ -269,7 +277,7 @@ def regrd(self, dev, reg, fmt = "B"):
         :param reg: register address 0-255
         :param fmt: :py:func:`struct.unpack` format string for the register contents, or an integer byte count
 
-        If device 0x75 has a 16-bit register 102, it can be read with:
+        If device 0x75 has a 16-bit unsigned big-endian register 102, it can be read with:
 
         >>> i2c.regrd(0x75, 102, ">H")
         4999
@@ -335,7 +343,6 @@ def monitor(self, s):
             self.__echo(0x40)
 
     def introspect(self):
-        """ Update all status variables """
         self.ser.write(b'J')
         r = self.ser.read(80)
         assert len(r) == 80, r
@@ -360,6 +367,11 @@ def __repr__(self):
             self.sda)
 
     def capture_start(self, idle=False, start = START, abyte = BYTE, stop = STOP):
+        """Enter I2C capture mode, capturing I2C transactions.
+        :param idle: If ``True`` the generator returns ``None`` when the bus is idle. If ``False`` the generator does nothing during bus idle.
+
+        :return: a generator which returns an object for each I2C primitive captured.
+        """
         self.__ser_w([ord('c')])
         def nstream():
             while True:

python/samples/mux.py

@@ -0,0 +1,40 @@
+import sys
+from i2cdriver import I2CDriver, EDS
+
+# Using a TCA9548A Low-Voltage 8-Channel I2C Switch
+# Three LM75B temperature sensors are connected to 
+# channels 0,1 and 2. All are at address 0x48.
+
+class Mux:
+    def __init__(self, i2, a = 0x70):
+        self.i2 = i2
+        self.a = a
+
+    def select(self, n):
+        assert n in range(8)
+        self.i2.start(self.a, 0)
+        self.i2.write([1 << n])
+        self.i2.stop()
+
+if __name__ == '__main__':
+    i2 = I2CDriver(sys.argv[1])
+
+    mux = Mux(i2)
+    sensors = [
+        (0, EDS.Temp(i2)),
+        (1, EDS.Temp(i2)),
+        (2, EDS.Temp(i2))
+        ]
+
+    # Reset all 8 channels
+    for chan in range(8):
+        mux.select(chan)
+        i2.reset()
+
+    def read(chan, dev):
+        mux.select(chan)
+        celsius = dev.read()
+        return celsius
+
+    while 1:
+        print(" ".join(["%.1f" % read(chan, dev) for chan,dev in sensors]))

testall

@@ -14,3 +14,4 @@ python -c 'from i2cdriver import I2CDriver'
 
 cd c
 make -f linux/Makefile
+make -f linux/Makefile.clang