Merge pull request #22 from ladyada/master

I2C and SPI fixes to bring more in line with busio

diff --git a/src/adafruit_blinka/microcontroller/raspi_23/spi.py b/src/adafruit_blinka/microcontroller/raspi_23/spi.py
index 27ead42ebc5eb9ca2f11e58031f0be3b4f43e816..a4e1158a6f79bce68c55131cd04dddb9c70d9b64 100755 (executable)
--- a/src/adafruit_blinka/microcontroller/raspi_23/spi.py
+++ b/src/adafruit_blinka/microcontroller/raspi_23/spi.py
@@ -30,9 +30,11 @@ class SPI:
         self.mode = mode
         self.bits = bits
 
-    def write(self, buf):
+    def write(self, buf, start=0, end=None):
         if not buf:
             return
+        if end is None:
+            end = len(buf)
         try:
             self._spi.open(self._port, 0)
             try:
@@ -42,15 +44,17 @@ class SPI:
             self._spi.max_speed_hz = self.baudrate
             self._spi.mode = self.mode
             self._spi.bits_per_word = self.bits
-            self._spi.writebytes([x for x in buf])
+            self._spi.writebytes([x for x in buf[start:end]])
             self._spi.close()
         except FileNotFoundError as not_found:
             print("Could not open SPI device - check if SPI is enabled in kernel!")
             raise
 
-    def readinto(self, buf):
+    def readinto(self, buf, start=0, end=None):
         if not buf:
             return
+        if end is None:
+            end = len(buf)
         try:
             self._spi.open(self._port, 0)
             try:
@@ -60,9 +64,9 @@ class SPI:
             self._spi.max_speed_hz = self.baudrate
             self._spi.mode = self.mode
             self._spi.bits_per_word = self.bits
-            data = self._spi.readbytes(len(buf))
-            for i in range(len(buf)):  # 'readinto' the given buffer
-              buf[i] = data[i]
+            data = self._spi.readbytes(end-start)
+            for i in range(end-start):  # 'readinto' the given buffer
+              buf[start+i] = data[i]
             self._spi.close()
         except FileNotFoundError as not_found:
             print("Could not open SPI device - check if SPI is enabled in kernel!")

diff --git a/src/busio.py b/src/busio.py
index 3523acd7289e172357725233f5a55439558f35a4..69cbca03a3300c59a2064b849193096c8a91e15f 100755 (executable)
--- a/src/busio.py
+++ b/src/busio.py
@@ -53,6 +53,8 @@ class I2C(Lockable):
         return self._i2c.readfrom_into(address, buffer, stop)
 
     def writeto(self, address, buffer, start=0, end=None, stop=True):
+        if isinstance(buffer, str):
+            buffer = bytes([ord(x) for x in buffer])
         if start is not 0 or end is not None:
             if end is None:
                 return self._i2c.writeto(address, memoryview(buffer)[start:], stop)
@@ -106,11 +108,11 @@ class SPI(Lockable):
         self._spi = None
         self._pinIds = None
 
-    def write(self, buf):
-        return self._spi.write(buf)
+    def write(self, buf, start=0, end=None):
+        return self._spi.write(buf, start, end)
 
-    def readinto(self, buf):
-        return self._spi.readinto(buf)
+    def readinto(self, buf, start=0, end=None, write_value=0):
+        return self._spi.readinto(buf, start, end)
 
     def write_readinto(self, buffer_out, buffer_in,  out_start=0, out_end=None, in_start=0, in_end=None):
         return self._spi.write_readinto(buffer_out, buffer_in, out_start, out_end, in_start, in_end)