Controlled Area Network board

CAN Board

Each pattern which is sent through the H and L-CAN is "infomation" which is a series of "0's" and "1's" which are digital signals sent as voltage levels, Above a set voltage it counts a "1" and below a set voltage it counts a "0" and a internal clock records the voltage at certain intervals.
By using the dual-trace function on a oscillloscope I captured the full pattern of the H-can and the L-can and identified which wire was the H-Can and the L-Can.                                                         NOTE# CH-A=1.00V CH-B=1.00V   M=25 micro seconds

This pattern is the original start and stop pattern, you can't see on the screen the channels but the top line is channel A and the bottom line is channel B. Channel A is the H-CAN, I know this because on the channel A the pattern starts on 3.5V and switches down to about 2.5V which means its the High CAN because it starts at 3.5V and switches down to 2.5V. Channel B is the L-CAN (Low CAN) because it does the complete opposite to the H-CAN ie. instead of starting at 3.5V and switching down it starts at 0.5V and switches down to about 2.5V which indicates that this is the L-CAN.                                                                          

  Relationship between the two patterns and their base voltages (what volts when not switched) 

-The H-CAN and L-CAN are opposites.

-Base voltages are 2.5V for both CANS.

-H-CAN is switching up.

-L-CAN is switching down.

-Both switch at thw same time.

Next i was asked to capture the following inputs on the oscilloscope and identify where it changes in relation to the original start stop pattern.

-right indicator

-left indicator

-rear wiper

-stoplights

-fuel pump

-reverse lights

NOTE# the divisions are the same as the original pattern (CH-A=1.00V  CH-B=1.00V and M=25 micro seconds) 

Right indicator

left indicator

Stop lights

Reverse lights

As you can see all these patterns are completely different to the original pattern, this is because each code has to be different to difine what needs to be switched on e.g. various sets of lights etc. this code is the amount of zeros and ones within each pattern which this amount changes depending on what needs to be switched on.

Using the wiring diagram and CAN board identify the input/output pins, wire colours, relay or transistor for the right hand indicator.
R indicator= 7-6
input voltage (pin 7)- RA4/tock I (6) then output signal from RB2/can tx and Rb3/canRx to pins 1 (TxD) and 2 (RxD) then the output pins 7CanH and 6CanL to Ic4 (communicator) and CanL to can receiver IC5 and then the output pins TxD to TXCAN/TXRXCAN and RXD to RXCAN/NC and from the outputs GP4/REF and then to OPTOC coupling which switches the transistor which responds to light from the LED which then switces another transistor on which then finally switches the right hand indicator on