pi: eeprom: added file to read/write AT28C EEPROM

This lets you write the AT28 EEPROM with the Raspberry Pi.

1 files changed, 129 insertions, 0 deletions

diff --git a/eeprom_pi.py b/eeprom_pi.py
new file mode 100644
index 0000000..2b46892
--- /dev/null
+++ b/eeprom_pi.py
@@ -0,0 +1,129 @@
+import RPi.GPIO as GPIO
+import time
+
+def cleanup():
+	GPIO.cleanup()
+
+def init_board(write = True):
+	GPIO.setmode(GPIO.BOARD)
+
+	if write:
+		oparm = GPIO.OUT
+	else:
+		oparm = GPIO.IN
+
+	# GPIO 0-7
+	# used as data pins, configure as input/output
+	GPIO.setup(11, oparm)
+	GPIO.setup(12, oparm)
+	GPIO.setup(13, oparm)
+	GPIO.setup(15, oparm)
+	GPIO.setup(16, oparm)
+	GPIO.setup(18, oparm)
+	GPIO.setup(22, oparm)
+	GPIO.setup(7, oparm)
+
+	# left side of T-cobbler, used as address pins
+	# configure address pins always out
+	GPIO.setup(26, GPIO.OUT)
+	GPIO.setup(24, GPIO.OUT)
+	GPIO.setup(23, GPIO.OUT)
+	GPIO.setup(21, GPIO.OUT)
+	GPIO.setup(19, GPIO.OUT)
+	GPIO.setup(10, GPIO.OUT)
+	GPIO.setup(8, GPIO.OUT)
+
+	# used to trigger a write
+	GPIO.setup(5, GPIO.OUT)
+
+	# used to read
+	GPIO.setup(3, GPIO.OUT)
+
+	# set the pins to high, pins are active low
+	GPIO.output(5, True)
+	GPIO.output(3, True)
+
+
+
+def read_data():
+	data = (GPIO.input(11))  
+	print(GPIO.input(11))
+	data |= (GPIO.input(12) << 0x1) 
+	print(GPIO.input(12))
+	data |= (GPIO.input(13) << 0x2) 
+	print(GPIO.input(13))
+	data |= (GPIO.input(15) << 0x3) 
+	print(GPIO.input(15))
+	data |= (GPIO.input(16) << 0x4) 
+	print(GPIO.input(16))
+	data |= (GPIO.input(18) << 0x5) 
+	print(GPIO.input(18))
+	data |= (GPIO.input(22) << 0x6) 
+	print(GPIO.input(22))
+	data |= (GPIO.input(7) << 0x7)
+	print(GPIO.input(7))
+	print("read data: %s" % data)
+	return data
+
+# data should be one byte
+def set_data(data):
+	GPIO.output(11, (data & 0x1) > 0)
+	print((data & 0x1) > 0)
+	GPIO.output(12, (data & 0x2) > 0)
+	print((data & 0x2) > 0)
+	GPIO.output(13, (data & 0x4) > 0)
+	print((data & 0x4) > 0)
+	GPIO.output(15, (data & 0x8) > 0)
+	print((data & 0x8) > 0)
+	GPIO.output(16, (data & 0x10) > 0)
+	print((data & 0x10) > 0)
+	GPIO.output(18, (data & 0x20) > 0)
+	print((data & 0x20) > 0)
+	GPIO.output(22, (data & 0x40) > 0)
+	print((data & 0x40) > 0)
+	GPIO.output(7, (data & 0x80) > 0)
+	print((data & 0x80) > 0)
+
+# address should be one byte
+def set_address(address):
+	GPIO.output(26, (address & 0x1) > 0)
+	print((address & 0x1) > 0)
+	GPIO.output(24, (address & 0x2) > 0)
+	print((address & 0x2) > 0)
+	GPIO.output(23, (address & 0x4) > 0)
+	print((address & 0x4) > 0)
+	GPIO.output(21, (address & 0x8) > 0)
+	print((address & 0x8) > 0)
+	GPIO.output(19, (address & 0x10) > 0)
+	print((address & 0x10) > 0)
+	GPIO.output(10, (address & 0x20) > 0)
+	print((address & 0x20) > 0)
+	GPIO.output(8, (address & 0x40) > 0)
+	print((address & 0x40) > 0)
+	# for DEBUG use only 7 address bits to have one left for read trigger
+	#GPIO.output(5, (address & 0x80) > 0)
+	#print((address & 0x80) > 0)
+
+def write_data_at(address, data):
+	print("set address to: %s" % address)
+	set_address(address)
+	print("set data to: %s" % data)
+	set_data(data)
+	# wait so everythings is stable
+	time.sleep(0.3)
+	# trigger write on pin 5
+	GPIO.output(5, False)
+	time.sleep(0.3)
+	GPIO.output(5, True)
+
+
+def read_data_at(address):
+	print("set address to: %s" % address)
+	set_address(address)
+	# wait a little bit so the address is stable
+	time.sleep(0.3)
+	# trigger output enable
+	GPIO.output(3, False)
+	data = read_data()
+	GPIO.output(3, True)
+	print("read data %s" % data)