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Topic: logic analyzer/sniffer for a novice? (Read 3 times) previous topic - next topic

scott_fx

Hey guys,

have a few arduino projects under my belt right now and i've been tackling a relatively ambitious project.  I want to step it up a notch and have the arduino mega piggy back a cruise control system for my boat.   It wont be going against the arduino guidelines as i'll just be using the arduino to simulate button presses.  The thing that i need to figure out is how to know what speed the controller is set at so that i can display that information on my arduino's screen.   

the module has an lcd gauge (thats not mine but its similar):
http://img853.imageshack.us/img853/155/imagerwi.jpg

it looks to have a 10 wire harness.   

i took it apart and noticed that the 4 buttons on the front panel had a handy 5 pin header and socket.  (4 buttons, 1 common ground) 
http://onfinite.com/libraries/1663907/87b.jpg

i also found this device online that lets you control the speed wireless while being towed:
http://www.nautiqueparts.com/wirelessremoteforcruisecontrol.aspx  (speed up/ slow down)



this leads me to believe that the button presses are not serial and and the connect directly to digital inputs on the master module.   that would leave 6 wires on that harness for the display.   two of which are power and ground.  that would lead me to believe that it's a serial lcd?
(edit:  i contacted the person who made that and the buttons do extend out from that wire harness.)

now to my question... does my logic sound correct?  and if so.   being new to coding and micro controllers.  would sniffing out the speed settings that are being sent to the lcd screen be within a novice's grasp?  and do you guys recommend any online tutorials/videos (or if you'd like to post directions here... id love that too)  that would show me the correct ways of accomplishing this task?



thanks in advance

scott

scott_fx

i'm assuming this is harder then i suspect?

Graynomad

Quote
6 wires on that harness for the display.   two of which are power and ground.  that would lead me to believe that it's a serial lcd?

That leaves 4, way more than required for a serial interface unless they use hardware handshaking.

Sniffing this would be a piece of cake IF you have a logic analyzer. If you don't you'd have to write something for your Arduino to do the job and that will be a task. That said there is at least one logic-analyzer-on-an-Arduino project around, I even think there was a post about it recently. I think it works with the SUMP client on your PC. That would make life easier.

______
Rob
Rob Gray aka the GRAYnomad www.robgray.com

scott_fx


Quote
6 wires on that harness for the display.   two of which are power and ground.  that would lead me to believe that it's a serial lcd?

That leaves 4, way more than required for a serial interface unless they use hardware handshaking.

Sniffing this would be a piece of cake IF you have a logic analyzer. If you don't you'd have to write something for your Arduino to do the job and that will be a task. That said there is at least one logic-analyzer-on-an-Arduino project around, I even think there was a post about it recently. I think it works with the SUMP client on your PC. That would make life easier.

______
Rob


thanks for the input.   If i decide this is within my skillset, I would be purchasing a logic analyzer, possibly the one that is an arduino shield but more then likely one of these two (unless there are better options):
http://dangerousprototypes.com/docs/Open_Bench_Logic_Sniffer
but leaning towards this one:
http://www.sparkfun.com/products/8938

Graynomad

I have no experience with the DP logic sniffer but I have the 8-bit Saleae (there's a 16-bit version as well now) and it's fantastic. Their support is good as well.

Last time I looked at the DP gadget it used Sump as the PC software, that is nowhere near as flash as the Saleae application.

Every time LAs are mentioned here a couple of us wax lyrical about how good the Saleae is.

______
Rob
Rob Gray aka the GRAYnomad www.robgray.com

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