fixed to work with regular python 'smbus2' module.

Reading status and setting fan speed works on my DPS1200 right here.
eeprom reading is borked for some reason right now but it's trivial and
not very interesting anyway

DPS-1200FB.py

@@ -69,18 +69,21 @@
 Cheers, that was fun. 
 DrTune/March 2017
 
+Updated April 2018 to use regular python smbus2 library. Sorry I didn't do that before. ;-)
+
 """
 
 import time
+from  smbus2 import SMBus,i2c_msg  #pip install smbus2
+
+
 
-import BananaPiI2CPort  #<<< you won't have this (is a custom class for my hacked kernel) - use SMBus instead! I will do this when I have a sec but it should be easy
-#import smbus  #<<You want to use this - convert the i2c.read and i2c.write to match
 
 
 class PowerSupply(object):
-    def __init__(self,address):  #address 0..7 reflecting the i2c address select bits on the PSU edge connector
-        self.i2c = BananaPiI2CPort.BananaPiI2CPort()    # 0 = /dev/i2c-0 (port I2C0), 1 = /dev/i2c-1 (port I2C1)
-        self.address=0x58
+    def __init__(self,i2cbus=0,address=7):  #address 0..7 reflecting the i2c address select bits on the PSU edge connector
+        self.i2c = SMBus(i2cbus)    # 0 = /dev/i2c-0 (port I2C0), 1 = /dev/i2c-1 (port I2C1)
+        self.address=0x58+address
         self.EEaddress=0x50+address
 
         self.numReg=0x58/2
@@ -91,10 +94,25 @@ def __init__(self,address):  #address 0..7 reflecting the i2c address select bit
 
     #not very interesting - read the 24c02 eeprom (you can write it too)
     def readEEPROM(self):
-        data=self.i2c.read(self.EEaddress,0,255)
-        print data
+        pos=0
+        data=""
+        while pos<256: #fixme
+            data+=self.i2c.read_i2c_block_data(self.EEaddress,pos,32)
+            pos+=32
         print "%s" % (" ".join([ "%02x" % ord(d) for d in data]) )
 
+    def readVar(self,address,writeInts,readCount):
+        #https://github.com/kplindegaard/smbus2  'dual i2c_rdrw'
+        write = i2c_msg.write(address, writeInts)
+        if readCount:
+            read = i2c_msg.read(address,readCount)
+        m=self.i2c.i2c_rdwr(write, read)
+        return [chr(n) for n in list(read)]
+
+    def writeVar(self,address,bytes):
+        asInts=[ord(d) for d in bytes]
+        self.i2c.write_i2c_block_data(address,asInts[0],asInts[1:])
+
     #the most useful
     def readDPS1200(self,reg,count):
         cs=reg+(self.address<<1)
@@ -103,7 +121,7 @@ def readDPS1200(self,reg,count):
         writeInts=[reg,regCS]   #send register # plus checksum
         #this should write [address,register,checksum] and then read two bytes (send address+read bit, read lsb,read msb)
         #note this device doesn't require you to use a "repeated start" I2C condition - you can just do start/write/stop;start/read/stop
-        return self.i2c.readVar(self.address,writeInts,count)
+        return self.readVar(self.address,writeInts,count)
 
     #  Writable registers/cmds:
     # Nothing very interesting discovered so far; you can control the fan speed. Not yet discovered how to turn 
@@ -150,7 +168,7 @@ def writeDPS1200(self,reg,value):
         #the checksum is the 'secret sauce'
         writeInts=[reg,valLSB,valMSB,regCS]  #write these 4 bytes to i2c
         bytes="".join([chr(n) for n in writeInts])
-        return self.i2c.writeVar(self.address, bytes)  #<<Fix to work with smbus
+        return self.writeVar(self.address, bytes) 
 
     def testWrite(self):
         value=0
@@ -187,9 +205,11 @@ def testWrite(self):
         (0x36>>1):["PEAK_AMPS_OUT",128.0],
         (0x3A>>1):["COOL_FLAGS1",0],             #unknown (from disassembly)
         (0x3c>>1):["COOL_FLAGS2",0],             #unknown (from disassembly)
-        (0x40>>1):["FAN_SOMETHING",1],          #unknown (from disassembly)
+        (0x40>>1):["FAN_TARGET_RPM",1],          #unknown (from disassembly)
         (0x44>>1):["VOLTAGE_THRESHOLD_1",1],    #unknown (from disassembly)
         (0x46>>1):["VOLTAGE_THRESHOLD_2",1],    #unknown (from disassembly)
+        (0x50>>1):["MAYBE_UNDERVOLTAGE_THRESH",32.0],    #unknown (from disassembly)
+        (0x52>>1):["MAYBE_OVERVOLTAGE_THRESH",32.0],    #unknown (from disassembly)
         #reading 0x57 reads internal EEPROM space in CPU (just logging info, e.g. hours in use)
         }
 
@@ -231,15 +251,24 @@ def read(self):
         return
         addr=self.address
 
+    def forceFanRPM(self,rpm):
+        #sets (forces) fan speed; lowest it will accept is 3300rpm
+        #conversly, 16000RPM is very, very fast indeed. 
+        #You probably (untested) have to keep writing this regularly if you want to override what the firmware wants to do based
+        #on its temp sensors
+        self.writeDPS1200(0x40,rpm)
+
+
 
 
-ps=PowerSupply(0)
+ps=PowerSupply(i2cbus=0,address=7)
+#ps.readEEPROM() #borked right now
 
 while True:
     print "\033c" #clear screen
     ps.read()
     time.sleep(0.1)
-    #ps.testWrite()
-#ps.write()
+
+    ps.forceFanRPM(3200) #test - don't do this unless you really want to override the fan for some reason
 
 

readme.md

@@ -43,7 +43,6 @@ c) Hence the "WattsOut" at low power levels (which is just the result of the PSU
 
 d) To test higher power levels you will be wanting some high-power resistors, probably in a bucket of water :-)
 
-
 This info/code (for what it's worth) is released under the MIT license.