Component: CAPTOUCH (CAL)

Author	Matrix Ltd
Version	1.0
Category	CAL

CAPTOUCH component

A low level implementation giving direct access to the CAL

Component Source Code

Please click here to download the component source project: FC_Comp_Source_temp/CAPTOUCH.fcfx

Please click here to view the component source code (Beta): FC_Comp_Source_temp/CAPTOUCH.fcfx

Detailed description

No detailed description exists yet for this component

Examples

Internal CAN schematic

External CAN schematic

CAN Message Decoding

The CAN component works together with the injector component to allow you to decode a CAN message ID into a meaningful command.

Example File CAN_Example1 When a key on the keypad is pressed the CAN components transmits a CAN packet.

The CAN packet is decoded by the injector component to give us a meaningful log on the console window.

High Level CAN Data Console

Low Level CAN Data Console

Reference from CAN Injector to ID decode file, $(srcdir) refers to the current project directory.

Demo CAN ID file File:CANID.csv

CAN Masks and Filters

How to work out which messages will be trapped by a particular mask/filter combination

Note that all values for message id's, masks and filters are numbers between 0x000 and 0x7FF.

Example 1

Mask0 = 0x0FF

Filter0 = 0x100

Filter1 = 0x050

In binary, this looks like:

Mask0 = 000 1111 1111

Filter0 = 001 0000 0000

Filter1 = 000 0101 0000

For the mask, a "1" signifies "check this bit" and a "0" means "ignore this bit"

So, these filters will accept the following messages ("x" = don't care)

Filter0 = xxx 0000 0000

Filter1 = xxx 0101 0000

i.e.

Filter0 = 0x000, 0x100, 0x200, 0x300, 0x400, 0x500, 0x600, 0x700

Filter1 = 0x050, 0x150, 0x250, 0x350, 0x450, 0x550, 0x650, 0x750

Example 2

Mask1 = 0x350

Filter2 = 0x200

Filter3 = 0x123

Filter4 = 0x3FF

Rewriting in binary:

Mask1 = 111 0101 0000

Filter2 = 010 0000 0000

Filter3 = 001 0010 0011

Filter4 = 111 1111 1111

Here, the mask will only check 4 bits and ignore the other 6. Here's what the filters will accept:

Filter2 = 010 x0x0 xxxx

Filter3 = 001 x0x0 xxxx

Filter4 = 111 x1x1 xxxx

They will actually trap a lot of messages (64 each!):

Filter2 = 0x200, 0x201, 0x202, ... 0x220, 0x221, ... 0x280, 0x281, ... 0x2A0, 0x2A1, ... 0x2AF

Filter3 = 0x100, 0x101, 0x102, ... 0x120, 0x121, ... 0x180, 0x181, ... 0x1A0, 0x1A1, ... 0x1AF

Filter4 = 0x750, 0x751, 0x752, ... 0x770, 0x771, ... 0x7D0, 0x7D1, ... 0x7F0, 0x7F1, ... 0x7FF

This second example is not very practical. In general, it is more logical to set the mask so that each filter accepts a consecutive range of messages.

As you can see, the mask determines which bits of the filters are actually looked at. Setting the mask to 0x000 will effectively mean that the filter will accept any incoming message. Also, the value of the mask directly relates to how many messages each filter will trap - i.e. 2^(number of '0' bits in the mask).

A useful way to use the mask would be to ignore the least significant bits. Lets say that you wanted the filters to accept 16 messages each - setting the Mask0 to 0x7F0 would achieve this. Then, setting the filters to the following:

Filter0 = 0x100

Filter1 = 0x110

would mean that the following messages are accepted:

Filter0 = 0x100, 0x101, 0x102, 0x103, 0x104, ... 0x10D, 0x10E, 0x10F

Filter1 = 0x110, 0x111, 0x112, 0x113, 0x114, ... 0x11D, 0x11E, 0x11F

Of course, for simple CAN applications you may wish to only accept one or two messages. Setting the mask to 0x7FF in this instance would mean that only the message ID specified by each filter would be accepted, e.g.

Mask1 = 0x7FF

Filter2 = 0x100

Filter5 = 0x200

This would mean that only messages 0x100 and 0x200 would be accepted into buffer 1.

Macro reference

Charge

	Charge
End drain and begin charging the circuit
[[File:]] -	Return

Drain

	Drain
Drain charge on the circuit
[[File:]] -	Return

Init

	Init
Initialise
[[File:]] -	Return

Reset

	Reset
Reset, set status bits to zero
[[File:]] -	Return

Stop

	Stop
Stop charging circuit
[[File:]] -	Return

Property reference

Properties