Jump to content
Sign in to follow this  
abecedarian

TI Hercules. Suitable for casual and hobby use?

Recommended Posts

In another thread, questions were raised about if the Hercules processors were suitable for hobbyist and casual users.

 

I'd like to discuss this.

 

The relevant content of the post was presented by @@RROMANO001 and is:

This board require a multilayer fine pitch with few um lines, this product cost much more than a simple LP, this is a security cortex R step locked, has sense offer in the low cost market?

Again there where two BP socket not fully wired and two socket, one 100 pin similar to EK-TM4c1294 and some fine pitch requiring again a board to connect emif and other peripheral... Has this a sense? Automotive and reliability devices has no limited budget as hobby and casual user.

Boosterpack is a quite good prototype form, I fully hate Arduino layout due it is not usable on a proto board, Beaglebone has another good .1" standard connector, I loved see new MAX10 board using capemodel:

http://www.arrow.com...na/altera/deca/

 

On high speed design .1" standard is not usable so special high speed connector are required, daughter board design is sometimes more difficult to design than full board from scratch.

Before we get too deep, I'll start with "two BP socket not fully wired".

The BP standard currently shown on TI's Build Your Own BoosterPack site depicts two pins on the headers declared as "reserved", though those were used on previous LPs.

post-26656-0-77606100-1433102282_thumb.jpg

 

 

 

"High-speed" design is subjective. FWIW, many of the traces on the new LC4537 LP are 0.5 mil... and they 90 degree many of them {gasp}. :o

 

I could tell you the most rapid signal I have to deal with on my engine might be 60 tooth wheel for position sensing on a shaft, and at 15000 revolutions per minute, that works out to 250 revolutions per second and further means 15000 signals per second with that 60 tooth wheel, so 15KHz or maybe 30KHz if you want to capture both rising and falling signals, right? Is that high speed? Does I2C/IIC work at 100KHz over 0.1" headers? Do ESC / motor controllers work over 0.1" headers?

 

 

 

I'll stop here because I want discussion.

Share this post


Link to post
Share on other sites

"High-speed" design is subjective. FWIW, many of the traces on the new LC4537 LP are 0.5 mil... and they 90 degree many of them {gasp}. :o

 

 Hi ABcderian, About this is not relative to motor control, if this processor got HRPWM from C2000 series resolution of both capture and compare are in the hundred pico second range so equalization of trace length and also impedance control are required if this feature has to be used.

Most worst is EMIF, this processor run @300MHz and adding an external SDRAM require high speed equalized design, EMIF are not on just two mezzanine and we are not sure traces are impedance and time delay controlled on LP.

Share this post


Link to post
Share on other sites

I concede that BGA is not "hobby" friendly, but this discussion should be about the LaunchPads themselves, not the chips they contain.

 Ultra fine pitch are not friendly to industrial market too due to reliability and cost of PCB. I don't hate BGA but I prefer usable sizes where PCB number of layer pitch and cost are all acceptable.

Share this post


Link to post
Share on other sites

@@RROMANO001 - Have you looked at the specifications of the N2HET peripherals?

 No, I delayed till mid of june, I am busy to prepare exam session and end of session school work. After that I evaluate also if preferred way seems to be FPGA only and MSP for support. I can be more interested on small footprint, I can evaluate Hercules series I never approached, I am not sure can fit on C2000 application or where TIVA was chosen for CAN support.

Step locked can be a good idea on PMSM control, maybe I can try vibration analysis and motion control on LP device.

 Thank for all hints.

 Roberto.

Share this post


Link to post
Share on other sites

Perhaps a better way to discuss this would be, "For what hobbyist applications would the Hercules part be well suited?"

 

The first thing that comes to my mind would be high-altitude balloon projects or cubesats that would be subject to cosmic rays.

 

Does anyone know if the Hercules architecture will really provide a benefit here?

Share this post


Link to post
Share on other sites

Possibly. Power consumption would be my first concern though. The ECC feature must be used in flash.

 

TI's FRAM MSP430's supposedly have an innate radiation immunity (well, the PZT storage medium itself, all transistors are still susceptible) which has been recognized and studied for space applications.

 

Sent from my Galaxy Note II using Tapatalk

Share this post


Link to post
Share on other sites

I have seen plenty of people using Arduinos and Raspberry Pis as flight computers for these applications, so clearly power consumption isn't *that* great of a concern.  ;-)

 

I agree that an MSP430 part would likely have lower power consumption than a Hercules part, but I would be willing to bet that a Hercules part -- when used/coded properly -- would consume *considerably* less power than what most people are actually using.

 

I mention this application because I have seen a fair number of discussions on flight computer failures.  Now personally, I suspect the primary cause to be related to vibration on spring-loaded connectors.  I've seen some pretty janky wiring jobs.  But cosmic radiation levels are much greater at high altitudes so this is a real possibility.  (BTW, janky *is* a real word now.  http://time.com/3724601/oxford-dictionary-janky-egot-ridesharing/)

 

I am aware that FRAM has some level of immunity to the effects of cosmic rays, but as I understand it the SRAM and the core logic could certainly be effected.  As such, the effects of a cosmic-ray induced bit flip could easily go unnoticed causing a series of cascading failures before the watchdog is triggered.  But then you still are left with all the mess between the cosmic ray event and the watchdog trigger.  (There is also no guarantee that a failure will result in triggering of the watchdog.)

 

As best as I can tell, the lock-step operation of the Hercules parts would provide much quicker notification of an event, and thus much quicker restart with less chance of data loss or corruption.  This is certainly no substitute for a fully rad-hard system, but it seems as if it gets you a long way in that direction for a fraction of the price.

 

In any case, it seems as if this could be a prime hobbyist application for the part.  I am *very* curious to know if anyone who knows more about the architecture of the Hercules can actually provide some more detail here.

Share this post


Link to post
Share on other sites

I hear ya, in that event the Hercules is superior in that it has ECC protection in its SRAM too. I also believe the internal busses have some sort of protection although I'm not quite clear on it. If folks are using RPi's then probably not a big concern power wise... I think I characterized the TMS570LS0432 at 150mA idle current or so.

 

Sent from my Galaxy Note II using Tapatalk

Share this post


Link to post
Share on other sites

  But then you still are left with all the mess between the cosmic ray event and the watchdog trigger.  (There is also no guarantee that a failure will result in triggering of the watchdog.)

 Radiation hardened in first can have shield, cosmic rays are hard to shield.

 Another point to take on sensitivity are device technology, 130nm are less sensitive than 65 and old large devices are even less sensitive to radiation.

About bit failure and redundancy when a particle collide silicon and flip some bit, when this failure get detected?

 What is the best chip geometry?

 Good question, ok if this is an hobby it is awesome but seems aerospace area than casual ;)

 Roberto

Share this post


Link to post
Share on other sites

Re: cube-sat / balloon stuff... a stupid question, maybe: couldn't 2 FRAM MSP430's, or maybe 3 for authoritative / voting purposes, do a Ping-Pong thing and watchdog each other and accomplish much the same thing? If one MSP faults out, it doesn't ping the others so the others reset it, or if the data from one doesn't fit with the others / certain criteria, a "majority rules" thing applies. A cosmic ray might affect one or the other, but it's highly unlikely one CR event will affect the group. Coding might be a bear to deal with, though coding for the Hercules isn't much easier.

 

The MSP430's, or even MSP432's, could possibly be coded in Energia, and retain some high degree of resiliency against data corruption.

 

And then there's costs involved with things too. Hercules aren't cheap: several MSP430's could probably be bought for the cost of one Hercules chip, for instance, and then board design constraints need considered too.

Share this post


Link to post
Share on other sites

"High-speed" design is subjective. FWIW, many of the traces on the new LC4537 LP are 0.5 mil... and they 90 degree many of them {gasp}. :o

 

 

I'll stop here because I want discussion.

 I suppose the green highlighted text was 5 mils(127um), it is a terrify measure scaring manufacturer and closing to lowest limit of very few in the world, I don't know so many can do these ultra fine lines.

 

http://www.we-online.com/web/en/leiterplatten/willkommen_/Willkommen.php

http://www.wedirekt.de/index.php/home

http://www.we-online.com/web/de/leiterplatten/layout/layout_service/layoutservice.php?parLANG=DE&parFOOTER=1008611&ls_name=&ls_country=DE&ls_plz=&pcb_search=Suchen

http://www.sfcircuits.com/pcb-production-capabilities/hdi-pcb-micro-circuits

 

if someone help grow this list, with cheap service too, I am proud ans grateful to.

 

 About 90

Share this post


Link to post
Share on other sites

Re: cube-sat / balloon stuff... a stupid question, maybe: couldn't 2 FRAM MSP430's, or maybe 3 for authoritative / voting purposes, do a Ping-Pong thing and watchdog each other and accomplish much the same thing? If one MSP faults out, it doesn't ping the others so the others reset it, or if the data from one doesn't fit with the others / certain criteria, a "majority rules" thing applies. A cosmic ray might affect one or the other, but it's highly unlikely one CR event will affect the group. Coding might be a bear to deal with, though coding for the Hercules isn't much easier.

 

The MSP430's, or even MSP432's, could possibly be coded in Energia, and retain some high degree of resiliency against data corruption.

 

And then there's costs involved with things too. Hercules aren't cheap: several MSP430's could probably be bought for the cost of one Hercules chip, for instance, and then board design constraints need considered too.

 

 Hi Abecedarian, I am not so expert on space program and new technology but I think MSP432 can be 65nm tech so it can be too much sensitive to radiation.

 About FRAM I don't know due I never used it, MSP satisfied me for long time also on very low power and I appreciated ENERGIA library was entering deep sleep as soon as possible.

 When radiation can be the issue radiation hardened technology has to be chosen and geometry give a main rule. About lock step, low speed large geometry are better, lock step is a big help, cannot be programmed on ENERGIA (IMHO), a space product must pass strict test and also if hobby it require now a licence so excluding some large area where no air traffic is present casual experimentation is limited to few people.

 Another application can be quadcopter and drone, too many use Arduino blah blah.. but they where too much unstable and unreliable!! Here lock step I see here as a MUST BE!

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...