Hacking a Firecracker module for the CAI WebControl

Sacarino

Member
I happened to be on the CAI website a while back and discovered that they now have X-10 support cooked into the 3.1.x PLC firmware. That got me pretty fired up, because I have a project that would be easily solved by the WebControl blasting out X-10, rather than waiting for the time (and lower temperature) to let me run cat5 through the attic. The how-to shows that you can use either a keyfob controller, a Firecracker, or a standalone transmitter so I sent the board off to be re-flashed and I dug my old Firecracker.

My problem is that my Firecracker looks nothing like theirs - the one I have must be an earlier board rev, because it's totally different (and uglier!). The chip seems to be the same PN and rev, but I'm not circuit savvy enough to know if the diode hack will work on the same pinout, so I was hoping that someone here could throw an educated thought my way. Worst case scenario is I try it and it doesn't work, right? If so, would this 310Mhz transmitter from Sparkfun work for me?

The CAI documentation contains this Firecracker:
index.php


The Firecracker on my desk:
index.php

index.php

index.php

index.php


I'd be in your debt if you could offer some guidance to a software geek!

Thanks for the help!
 
All X10 firecracker or keychain remote,even the palmhold remote doing similar thing in its RF part.
They all have a small processor, one of its processor output is driving the RF transistor's base through a resistor.
If you look your last picture and SOT-23 transistor, the one pin on top is collector, the pin at left lower one is base, and the one on lower right is
emitter.

You can simply have diode to hook up to the IC pin 5, which is connected to resistor marked with 273 (probably 2.7K), that is the correct pin.
Hook that to WebControl TTL8 sending X10 RF commands through the RF transmitter.
 
All X10 firecracker or keychain remote,even the palmhold remote doing similar thing in its RF part.
They all have a small processor, one of its processor output is driving the RF transistor's base through a resistor.
If you look your last picture and SOT-23 transistor, the one pin on top is collector, the pin at left lower one is base, and the one on lower right is
emitter.

You can simply have diode to hook up to the IC pin 5, which is connected to resistor marked with 273 (probably 2.7K), that is the correct pin.
Hook that to WebControl TTL8 sending X10 RF commands through the RF transmitter.

Hm, ok... So do I have to leave the card attached to the DB9 shell or can I just wire it directly to the WebControl? If we're keeping what was previously the RTS and GND pins, does the new diode on IC pin 5 take the place of the brown wire that was the DTR signal?
 
If you want the actual schematic of the Firecracker.
It is in the FCC Database.
https://fjallfoss.fcc.gov/oetcf/eas/reports/GenericSearch.cfm
Grantee B4S
Product Code CM17A
In the details section.

Schematic:
View attachment CM17ASCH.pdf

Pin 5 of the IC looks like the RF transmitter control.
Seems to be used for an external signal to key the transmitter on and off.

The Sparkfun is 315 Mhz and not adjustable to the X10 310MHz.
 
The 315MHz transmitter can not be modified easily, since it has a resonance device on it.
In addition, getting a X10 keychain remote or firecracker is cheaper. You can solder 3 wires to put this
transmitter anywhere, few feet away from WebControl board.
 
Schematic:
View attachment 4047

Pin 5 of the IC looks like the RF transmitter control.
Seems to be used for an external signal to key the transmitter on and off.

That's exactly right, and it all makes sense to me now. The WebControl leaves the TTL7 output high the entire time to act as Vdd for the IC, and then the transmitter is toggled via TTL8 - based on whatever house code/unit code you've told it to transmit. Très Cool.

The Sparkfun is 315 Mhz and not adjustable to the X10 310MHz.

I went down the rabbit hole and found a site where you can buy the 310Mhz resonators to swap out... albeit on a more hackable transmitter. However, short of a learning experience, it doesn't make much sense to go that route since it's certainly not cost effective as CAI_Support has noted.

Thanks for the help! Took a 2nd pass through the documentation to realize the unit code translation, but I've got it up and running. :)
 
The attached picture showing X10-Keychain remote wiring for sending X10 RF commands
 

Attachments

  • X10-kr19a-small.jpg
    X10-kr19a-small.jpg
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that's neat, so are you basically hacking one or the other to allow an "outside" device to Tx on the Rf portion of the circuits?
 
That is correct. Since there is no 310MHz transmitter on the market, the easiest way is to hack up the real X10 RF devices. We tested on keychain remote, on firecracker, and on palm remote. They all working great. Since it operates on 5V power provided by WebControl, keychain remote can send X10 RF farther than on the 3V battery. Firecracker has 5V regulator, so WebControl's 5V supply makes no difference on its range. For EU, it uses a different frequency, which you can get a RF transmitter easily.
 
I got this electric mattress pad:
http://www.jcpenney.com/jcp/X6.aspx?GrpTyp=STY&ItemID=1841229&Nao=0&SearchRedirect=True&Ne=4+840+877+878+5+961+6+29+3+579+963+1014+1031+8+587+15+12+1011+598+11+506+10+23+585+969+596+1022+586+1007+879+968+1027+18+904+903+833+949&NOffset=0&Ntt=electric+blanket&SearchString=electric+blanket&N=4294959029&SO=0&PSO=0&cmAMS_T=XGN5&cmAMS_C=CROSSSELL&cmAMS_Z=XGN5BOTTOMOFRESULTS&CmCatId=searchresults
and it works well. The only problem was I always forgot to turn it off in the morning. With a modified X10 key chain and WebControl, I made it turn on at the evening and off in the morning automatically. I added those lines to my gen 1 WebCtrol board:
START
...
...
TSTEQ CH 23
CALLSUB HEATON
HEAT1:
TSTEQ CH 7
CALLSUB HEATOFF
HEAT2:
NOP
END

HEATON:
TSTEQ RAM3 1
GOTO HEAT1
X10 1 15 ON
SET RAM3 1
RET

HEATOFF:
TSTEQ RAM3 0
GOTO HEAT2
X10 1 15 OFF
SET RAM3 0
RET

My house code is B and X10 appliance ID is 16. Since CAI's X10 starts from 0, so that I shifted the number accordingly. This will send out one X10 on command on 11PM and one X10 turn off command on 7AM. I put all electric mattress pads in my house on the same device ID, so they are turned off all together at 7AM.
 
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