Updated openocd and i2c

software/i2c.py

@@ -0,0 +1,61 @@
+import time
+import smbus
+
+i2c_ch = 1
+
+# TMP102 address on the I2C bus
+i2c_address = 0x20
+
+# Register addresses
+reg_temp = 0x00
+reg_config = 0x01
+
+# Calculate the 2's complement of a number
+def twos_comp(val, bits):
+    if (val & (1 << (bits - 1))) != 0:
+        val = val - (1 << bits)
+    return val
+
+# Read temperature registers and calculate Celsius
+def read_temp():
+
+    # Read temperature registers
+    val = bus.read_i2c_block_data(i2c_address, reg_temp, 2)
+    # NOTE: val[0] = MSB byte 1, val [1] = LSB byte 2
+    print ("!shifted val[0] = ", bin(val[0]), "val[1] = ", bin(val[1]))
+
+    temp_c = (val[0] << 4) | (val[1] >> 4)
+    #print (" shifted val[0] = ", bin(val[0] << 4), "val[1] = ", bin(val[1] >> 4))
+    #print (bin(temp_c))
+
+    # Convert to 2s complement (temperatures can be negative)
+    temp_c = twos_comp(temp_c, 12)
+
+    # Convert registers value to temperature (C)
+    temp_c = temp_c * 0.0625
+
+    return temp_c
+
+# Initialize I2C (SMBus)
+bus = smbus.SMBus(i2c_ch)
+
+# Read the CONFIG register (2 bytes)
+val = bus.read_i2c_block_data(i2c_address, reg_config, 2)
+print("Old CONFIG:", val)
+
+# Set to 4 Hz sampling (CR1, CR0 = 0b10)
+val[1] = val[1] & 0b00111111
+val[1] = val[1] | (0b10 << 6)
+
+# Write 4 Hz sampling back to CONFIG
+bus.write_i2c_block_data(i2c_address, reg_config, val)
+
+# Read CONFIG to verify that we changed it
+val = bus.read_i2c_block_data(i2c_address, reg_config, 2)
+print("New CONFIG:", val)
+
+# Print out temperature every second
+while True:
+    temperature = read_temp()
+    print(round(temperature, 2), "C")
+    time.sleep(1)

software/openocd_rpi.cfg

@@ -1,6 +1,9 @@
 adapter driver sysfsgpio
 transport select swd
 
+# gdb network
+bindto 0.0.0.0
+
 # Header pin numbers for SWD: 25 24
 sysfsgpio swd_nums 25 24
 

software/readI2Cpi.py

@@ -0,0 +1,22 @@
+# i2ctest.py
+# A brief demonstration of the Raspberry Pi I2C interface, using the Sparkfun
+# Pi Wedge breakout board and a SparkFun MCP4725 breakout board:
+# https://www.sparkfun.com/products/8736
+
+import smbus
+import time 
+
+# I2C channel 1 is connected to the GPIO pins
+channel = 1
+
+#  MCP4725 defaults to address 0x60
+address = 0x20
+
+
+# Initialize I2C (SMBus)
+bus = smbus.SMBus(channel)
+
+# Create a sawtooth wave 16 times
+data = bus.read_i2c_block_data(address, 0x0, 8)
+print(data)
+time.sleep(10)