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Discussion Groups | MSP430 | Cat 5 - JTAG extension?
The purpose of this group is to foster exchange of information on the Texas Instruments MSP430 family of microcontrollers and related tools. Everyone welcome, all levels of familiarity/expertise.
Cat 5 - JTAG extension? - "Robert J. Wilson" - Aug 2 15:47:13 2009
Hi,
Before running the experiment, I checked the archives and didn't seen any relevant postings for "JTAG distance". I'm working on a rapid prototype and plan to put an MSP430 in the engine compartment and extend the JTAG ~10 ft (~3 m.) back to the cabin and the eZ430 USB fob. Any best guesses on distance limitations using Cat-5 cable and RJ-45 blocks?
The reason is testing revealed the MSP430 daughter has survived 100C but the USB eZ430 failed. Hence the reason why I'd like to extend the JTAG into the cabin. The USB interface might not survive engine compartment temperatures.
Yes, I'll share my results but thought I'd ask first if anyone had tried this approach to extending JTAG using Cat-5 cable. Checking the Cat-5 specifications:
4 MHz, 13dB/1,000 ft
28.6 ohm/1000 ft
14 pF/ft
100 ohm impedance
Back of the envelope for 10 ft. (~3 m) Cat-5 suggests:
.13 dB attenuation, 4 MHz
.572 ohms, round-trip
280 pF capacitance, round trip
Thanks,
Bob Wilson
------------------------------------
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Before running the experiment, I checked the archives and didn't seen any relevant postings for "JTAG distance". I'm working on a rapid prototype and plan to put an MSP430 in the engine compartment and extend the JTAG ~10 ft (~3 m.) back to the cabin and the eZ430 USB fob. Any best guesses on distance limitations using Cat-5 cable and RJ-45 blocks?
The reason is testing revealed the MSP430 daughter has survived 100C but the USB eZ430 failed. Hence the reason why I'd like to extend the JTAG into the cabin. The USB interface might not survive engine compartment temperatures.
Yes, I'll share my results but thought I'd ask first if anyone had tried this approach to extending JTAG using Cat-5 cable. Checking the Cat-5 specifications:
4 MHz, 13dB/1,000 ft
28.6 ohm/1000 ft
14 pF/ft
100 ohm impedance
Back of the envelope for 10 ft. (~3 m) Cat-5 suggests:
.13 dB attenuation, 4 MHz
.572 ohms, round-trip
280 pF capacitance, round trip
Thanks,
Bob Wilson
------------------------------------
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Cat 5 - JTAG extension? - OneStone - Aug 2 16:09:24 2009
nOT TRIED cat-5. The older parallel programmers were a nightmare with
the ribbon cable connection to the JTAG box. anywhere near an older LCD
display and they'd garbage themselves. however I have shoved the USB
dongle at the end of 4 USB connectors linked together (don't ask!! I was
laid up in bed and that was as close as I could get to the work bench!)
and that was fine. Conversely, similar situation, I've debugged with the
dongle directly into a laptop and the test piece on the end of about 8
feet of shielded 4 core cable. Similar deal, I was in bed and needed to
get the device outside to debug it. Not a car though. Obviously the
usual advice would apply, protect against automotive size spikes, and if
powering from the car then automotive size load dumps. these thing do go
OK in cars generally. A lot would perhaps depend on how you route it.
obvious stuff, avoid the ignition leads and injector drivers if you can.
One thing I have found is that the little 4 way connectors on the EZ430
dongles are not the best, in fact they're pretty shitty, and even a
slight movement if they are stressed at all can fracture them. I have a
collection of dead ones. Luckily they are cheap. It's worth a try anyway.
Al
Robert J. Wilson wrote:
> Hi,
>
> Before running the experiment, I checked the archives and didn't seen any relevant postings for "JTAG distance". I'm working on a rapid prototype and plan to put an MSP430 in the engine compartment and extend the JTAG ~10 ft (~3 m.) back to the cabin and the eZ430 USB fob. Any best guesses on distance limitations using Cat-5 cable and RJ-45 blocks?
>
> The reason is testing revealed the MSP430 daughter has survived 100C but the USB eZ430 failed. Hence the reason why I'd like to extend the JTAG into the cabin. The USB interface might not survive engine compartment temperatures.
>
> Yes, I'll share my results but thought I'd ask first if anyone had tried this approach to extending JTAG using Cat-5 cable. Checking the Cat-5 specifications:
>
> 4 MHz, 13dB/1,000 ft
> 28.6 ohm/1000 ft
> 14 pF/ft
> 100 ohm impedance
>
> Back of the envelope for 10 ft. (~3 m) Cat-5 suggests:
>
> .13 dB attenuation, 4 MHz
> .572 ohms, round-trip
> 280 pF capacitance, round trip
>
> Thanks,
> Bob Wilson
>
> ------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
the ribbon cable connection to the JTAG box. anywhere near an older LCD
display and they'd garbage themselves. however I have shoved the USB
dongle at the end of 4 USB connectors linked together (don't ask!! I was
laid up in bed and that was as close as I could get to the work bench!)
and that was fine. Conversely, similar situation, I've debugged with the
dongle directly into a laptop and the test piece on the end of about 8
feet of shielded 4 core cable. Similar deal, I was in bed and needed to
get the device outside to debug it. Not a car though. Obviously the
usual advice would apply, protect against automotive size spikes, and if
powering from the car then automotive size load dumps. these thing do go
OK in cars generally. A lot would perhaps depend on how you route it.
obvious stuff, avoid the ignition leads and injector drivers if you can.
One thing I have found is that the little 4 way connectors on the EZ430
dongles are not the best, in fact they're pretty shitty, and even a
slight movement if they are stressed at all can fracture them. I have a
collection of dead ones. Luckily they are cheap. It's worth a try anyway.
Al
Robert J. Wilson wrote:
> Hi,
>
> Before running the experiment, I checked the archives and didn't seen any relevant postings for "JTAG distance". I'm working on a rapid prototype and plan to put an MSP430 in the engine compartment and extend the JTAG ~10 ft (~3 m.) back to the cabin and the eZ430 USB fob. Any best guesses on distance limitations using Cat-5 cable and RJ-45 blocks?
>
> The reason is testing revealed the MSP430 daughter has survived 100C but the USB eZ430 failed. Hence the reason why I'd like to extend the JTAG into the cabin. The USB interface might not survive engine compartment temperatures.
>
> Yes, I'll share my results but thought I'd ask first if anyone had tried this approach to extending JTAG using Cat-5 cable. Checking the Cat-5 specifications:
>
> 4 MHz, 13dB/1,000 ft
> 28.6 ohm/1000 ft
> 14 pF/ft
> 100 ohm impedance
>
> Back of the envelope for 10 ft. (~3 m) Cat-5 suggests:
>
> .13 dB attenuation, 4 MHz
> .572 ohms, round-trip
> 280 pF capacitance, round trip
>
> Thanks,
> Bob Wilson
>
> ------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Cat 5 - JTAG extension? - "Robert J. Wilson" - Aug 2 17:54:50 2009
--- In m...@yahoogroups.com, OneStone wrote:
>
. . .
> Not a car though. Obviously the
> usual advice would apply, protect against automotive size spikes, and if
> powering from the car then automotive size load dumps. these thing do go
> OK in cars generally. A lot would perhaps depend on how you route it.
> obvious stuff, avoid the ignition leads and injector drivers if you can.
Thanks, I'm trying to be careful but being able to use the JTAG as my interface device simplifies the task. It really comes down to how much cable load the JTAG interface can take and whether or not the CAT-5 twist is enough for these short distances.
Bob Wilson
------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
>
. . .
> Not a car though. Obviously the
> usual advice would apply, protect against automotive size spikes, and if
> powering from the car then automotive size load dumps. these thing do go
> OK in cars generally. A lot would perhaps depend on how you route it.
> obvious stuff, avoid the ignition leads and injector drivers if you can.
Thanks, I'm trying to be careful but being able to use the JTAG as my interface device simplifies the task. It really comes down to how much cable load the JTAG interface can take and whether or not the CAT-5 twist is enough for these short distances.
Bob Wilson
------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Cat 5 - JTAG extension? - merapcb - Aug 3 2:13:46 2009
My experience with trying to use CTA5 on SPI might be relevant here. Basically I wanted to
remote a SPI device some 2 meters from the MSP board. I got my RJ45 connection and CAT5
cable and all looked great. Only thing it didn't work. Long story short, because of the
twisted pairs in the CAT5, the signals were disturbing one another and giving noise of
canceling each other out. I had to resort to flat cable (or non-twisted 8 core cable).
Hope this helps.
--- In m...@yahoogroups.com, "Robert J. Wilson" wrote:
>
> Hi,
>
> Before running the experiment, I checked the archives and didn't seen any relevant postings for "JTAG distance". I'm working on a rapid prototype and plan to put an MSP430 in the engine compartment and extend the JTAG ~10 ft (~3 m.) back to the cabin and the eZ430 USB fob. Any best guesses on distance limitations using Cat-5 cable and RJ-45 blocks?
>
> The reason is testing revealed the MSP430 daughter has survived 100C but the USB eZ430 failed. Hence the reason why I'd like to extend the JTAG into the cabin. The USB interface might not survive engine compartment temperatures.
>
> Yes, I'll share my results but thought I'd ask first if anyone had tried this approach to extending JTAG using Cat-5 cable. Checking the Cat-5 specifications:
>
> 4 MHz, 13dB/1,000 ft
> 28.6 ohm/1000 ft
> 14 pF/ft
> 100 ohm impedance
>
> Back of the envelope for 10 ft. (~3 m) Cat-5 suggests:
>
> .13 dB attenuation, 4 MHz
> .572 ohms, round-trip
> 280 pF capacitance, round trip
>
> Thanks,
> Bob Wilson
>
------------------------------------
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
--- In m...@yahoogroups.com, "Robert J. Wilson"
>
> Hi,
>
> Before running the experiment, I checked the archives and didn't seen any relevant postings for "JTAG distance". I'm working on a rapid prototype and plan to put an MSP430 in the engine compartment and extend the JTAG ~10 ft (~3 m.) back to the cabin and the eZ430 USB fob. Any best guesses on distance limitations using Cat-5 cable and RJ-45 blocks?
>
> The reason is testing revealed the MSP430 daughter has survived 100C but the USB eZ430 failed. Hence the reason why I'd like to extend the JTAG into the cabin. The USB interface might not survive engine compartment temperatures.
>
> Yes, I'll share my results but thought I'd ask first if anyone had tried this approach to extending JTAG using Cat-5 cable. Checking the Cat-5 specifications:
>
> 4 MHz, 13dB/1,000 ft
> 28.6 ohm/1000 ft
> 14 pF/ft
> 100 ohm impedance
>
> Back of the envelope for 10 ft. (~3 m) Cat-5 suggests:
>
> .13 dB attenuation, 4 MHz
> .572 ohms, round-trip
> 280 pF capacitance, round trip
>
> Thanks,
> Bob Wilson
>
------------------------------------
______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Cat 5 - JTAG extension? - Stuart_Rubin - Aug 3 8:40:28 2009
It may sound a little nutty, but Olimex has a "wireless USB JTAG".
http://www.olimex.com/dev/msp-jtag-rf.html
http://www.sparkfun.com/commerce/advanced_search_result.php?keywords=MSP430-JTAG-RF&x=0&y=0&search_section=products
It seems to be designed for situations like yours. I haven't tried it. The price is a little higher than a TI or Software FET, but not terrible.
If you do take this path, please share your experiences with the group!
Stuart
--- In m...@yahoogroups.com, "Robert J. Wilson" wrote:
>
> Hi,
>
> Before running the experiment, I checked the archives and didn't seen any relevant postings for "JTAG distance". I'm working on a rapid prototype and plan to put an MSP430 in the engine compartment and extend the JTAG ~10 ft (~3 m.) back to the cabin and the eZ430 USB fob. Any best guesses on distance limitations using Cat-5 cable and RJ-45 blocks?
>
> The reason is testing revealed the MSP430 daughter has survived 100C but the USB eZ430 failed. Hence the reason why I'd like to extend the JTAG into the cabin. The USB interface might not survive engine compartment temperatures.
>
> Yes, I'll share my results but thought I'd ask first if anyone had tried this approach to extending JTAG using Cat-5 cable. Checking the Cat-5 specifications:
>
> 4 MHz, 13dB/1,000 ft
> 28.6 ohm/1000 ft
> 14 pF/ft
> 100 ohm impedance
>
> Back of the envelope for 10 ft. (~3 m) Cat-5 suggests:
>
> .13 dB attenuation, 4 MHz
> .572 ohms, round-trip
> 280 pF capacitance, round trip
>
> Thanks,
> Bob Wilson
>
------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
http://www.olimex.com/dev/msp-jtag-rf.html
http://www.sparkfun.com/commerce/advanced_search_result.php?keywords=MSP430-JTAG-RF&x=0&y=0&search_section=products
It seems to be designed for situations like yours. I haven't tried it. The price is a little higher than a TI or Software FET, but not terrible.
If you do take this path, please share your experiences with the group!
Stuart
--- In m...@yahoogroups.com, "Robert J. Wilson"
>
> Hi,
>
> Before running the experiment, I checked the archives and didn't seen any relevant postings for "JTAG distance". I'm working on a rapid prototype and plan to put an MSP430 in the engine compartment and extend the JTAG ~10 ft (~3 m.) back to the cabin and the eZ430 USB fob. Any best guesses on distance limitations using Cat-5 cable and RJ-45 blocks?
>
> The reason is testing revealed the MSP430 daughter has survived 100C but the USB eZ430 failed. Hence the reason why I'd like to extend the JTAG into the cabin. The USB interface might not survive engine compartment temperatures.
>
> Yes, I'll share my results but thought I'd ask first if anyone had tried this approach to extending JTAG using Cat-5 cable. Checking the Cat-5 specifications:
>
> 4 MHz, 13dB/1,000 ft
> 28.6 ohm/1000 ft
> 14 pF/ft
> 100 ohm impedance
>
> Back of the envelope for 10 ft. (~3 m) Cat-5 suggests:
>
> .13 dB attenuation, 4 MHz
> .572 ohms, round-trip
> 280 pF capacitance, round trip
>
> Thanks,
> Bob Wilson
>
------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
Re: Cat 5 - JTAG extension? - martin_schoenegg - Aug 3 10:09:37 2009
Hi Robert,
> extend the JTAG ~10 ft (~3 m.) back to the cabin and the
> eZ430 USB fob. Any best guesses on distance limitations
> using Cat-5 cable and RJ-45 blocks?
The problem and may be the solution is in the datas you listed below:
> Checking the Cat-5 specifications:
> 4 MHz, 13dB/1,000 ft
> 28.6 ohm/1000 ft
> 14 pF/ft
> 100 ohm impedance
Ethernet for example uses 100 Ohm drivers to drive these lines. If you would do this too, there will be no problems. Standard JTAG is not 100 Ohm. So if you spent a drivercircuit on both sides of the cable there will be no problem to drive 100 meters.
> Back of the envelope for 10 ft. (~3 m) Cat-5 suggests:
> .13 dB attenuation, 4 MHz
forget this, this is only relevant for a 100 ohm driver/receiver
> .572 ohms, round-trip
so this wouldn't be any problem
> 280 pF capacitance, round trip
why round trip? you want to drive 10 ft. teh relevant capacity that is seen by your driver circuit is 140 pf. As far as I remember the JTAG-devices are fitted with 74XY24x drivers. They should have less problems with this but the MSP could habe this. So the first thing i would try is to spent an additional 74AC244 or something like that on the MSP side of the CAT5-JTAG-cable. If this is not enough, use 100 Ohm drivers on both sides.
Marte
------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )
> extend the JTAG ~10 ft (~3 m.) back to the cabin and the
> eZ430 USB fob. Any best guesses on distance limitations
> using Cat-5 cable and RJ-45 blocks?
The problem and may be the solution is in the datas you listed below:
> Checking the Cat-5 specifications:
> 4 MHz, 13dB/1,000 ft
> 28.6 ohm/1000 ft
> 14 pF/ft
> 100 ohm impedance
Ethernet for example uses 100 Ohm drivers to drive these lines. If you would do this too, there will be no problems. Standard JTAG is not 100 Ohm. So if you spent a drivercircuit on both sides of the cable there will be no problem to drive 100 meters.
> Back of the envelope for 10 ft. (~3 m) Cat-5 suggests:
> .13 dB attenuation, 4 MHz
forget this, this is only relevant for a 100 ohm driver/receiver
> .572 ohms, round-trip
so this wouldn't be any problem
> 280 pF capacitance, round trip
why round trip? you want to drive 10 ft. teh relevant capacity that is seen by your driver circuit is 140 pf. As far as I remember the JTAG-devices are fitted with 74XY24x drivers. They should have less problems with this but the MSP could habe this. So the first thing i would try is to spent an additional 74AC244 or something like that on the MSP side of the CAT5-JTAG-cable. If this is not enough, use 100 Ohm drivers on both sides.
Marte
------------------------------------
(You need to be a member of msp430 -- send a blank email to msp430-subscribe@yahoogroups.com )