REV C Changes

83 views
Skip to first unread message

Gerald Coley

unread,
Dec 16, 2008, 12:28:10 PM12/16/08
to beagl...@googlegroups.com
We are looking to add some PWM signals to the expansion connector. This will be valuable for robotics and other functions. We are considering two different ways to accomplish this. Our goal is to make this as non-disruptive as possible and to have a zero cost impact.
 
The current plan is to replace the following pins on the OMAP3530 with different pins that will not change the available functions on those expansion pins, but it will add the PWM signals to them. One side affect is that the pin muxing will change for these pins on the Rev C. There are ID pins on the REV C board that will allow the SW to identify if the board is a REV C or REV B. Based on that reading the drivers could set the pin muxing accordingly to make the pins be in the correct mode. No functionality is lost because of this change. Below are the affected signals:
 

  CURRENT ASSIGNMENTS

EXP Pin 4 

McBSP3_DX            UART2_CTS      GPIO_140          OMAP Pin  AE6

EXP PIN 6 McBSP3_CLKX        UART2_TX         GPIO_142           OMAP Pin  AF5

EXP PIN 8  McBSP3_

FSX         UART2_RX        GPIO_143              OMAP Pin   AE5
 
 NEW ASSIGNMENTS
 
EXP PIN 4 UART2_CTS        McBSP3_DX       gpt9_pwm_evt     GPIO_144       OMAP Pin AB26

EXP PIN 6 UART2_TX        McBSP3_CLKX    gpt11_pwm _evt   GPIO_146      OMAP Pin  AA25

EXP PIN 8 UART2_RX       

McBSP3_FSX       gpt8_pwm_evt     GPIO_147       OMAP Pin  AD25
 
The other option would be to add pins to the expansion connector and add only two PWM signals. Those added signals in affect will only have use as a PWM signal as the other signals on those pins already exist on the expansion connector. This could also result in the connector having to move from its current location on the board.
 
I would like to get everyones input on this as soon as possible. We are planning to release the board in a week and I need to get this change in.
 
Thank you!
 
Gerald
 

Gerald Coley

unread,
Dec 16, 2008, 12:28:40 PM12/16/08
to beagl...@googlegroups.com

emeb

unread,
Dec 16, 2008, 1:15:36 PM12/16/08
to Beagle Board
I'd love to see more I/O pins on the expansion connector, but it seems
to me that moving the connector location would potentially obsolete
any existing / planned expansion boards. Tweaking software to check
the board ID prior to talking to GPIO seems like a lower impact way to
add PWM functions.

Adding PWM pins without moving the connector would be the best of
both, especially if you could add pins whose other muxed functions
aren't already available on the connector. If that's not possible
though then the assignments you've given above seem like a reasonable
compromise.

Eric

On Dec 16, 10:28 am, "Gerald Coley" <ger...@beagleboard.org> wrote:
> We are looking to add some PWM signals to the expansion connector. This will
> be valuable for robotics and other functions. We are considering two
> different ways to accomplish this. Our goal is to make this as
> non-disruptive as possible and to have a zero cost impact.
>
> The current plan is to replace the following pins on the OMAP3530 with
> different pins that will not change the available functions on those
> expansion pins, but it will add the PWM signals to them. One side affect is
> that the pin muxing will change for these pins on the Rev C. There are ID
> pins on the REV C board that will allow the SW to identify if the board is a
> REV C or REV B. Based on that reading the drivers could set the pin
> muxingaccordingly to make the pins be in
> the correct mode. No functionality is lost because of this change. Below are
> the affected signals:
>
> *
>
>   CURRENT ASSIGNMENTS
> **
>
> EXP Pin 4  *McBSP3_DX            UART2_CTS      GPIO_140          *OMAP Pin
> AE6*
>
> *EXP PIN 6 *McBSP3_CLKX        UART2_TX         GPIO_142           *OMAPPin
> AF5*
> *
>
> EXP PIN 8  McBSP3_*FSX         UART2_RX        GPIO_143
> *OMAPPin   AE5
> *
>
>  *NEW ASSIGNMENTS*
> **
> *EXP PIN 4* UART2_CTS        McBSP3_DX       gpt9_pwm_evt     GPIO_144
> *OMAP Pin *AB26
>
> *EXP PIN 6 *UART2_TX        McBSP3_CLKX    gpt11_pwm _evt   GPIO_146      *OMAP
> Pin  AA25*
> *
>
> EXP PIN 8 UART2_RX       *McBSP3_FSX       gpt8_pwm_evt     GPIO_147
>     *OMAP
> Pin  AD25*

Keith Williams

unread,
Dec 16, 2008, 1:19:57 PM12/16/08
to beagl...@googlegroups.com
As long as the MCBSP signals are staying--I'm all for it.

Gerald Coley wrote:
> We are looking to add some PWM signals to the expansion connector.
> This will be valuable for robotics and other functions. We are
> considering two different ways to accomplish this. Our goal is to make
> this as non-disruptive as possible and to have a zero cost impact.
>
> The current plan is to replace the following pins on the OMAP3530 with
> different pins that will not change the available functions on those
> expansion pins, but it will add the PWM signals to them. One side
> affect is that the pin muxing will change for these pins on the Rev C.
> There are ID pins on the REV C board that will allow the SW to
> identify if the board is a REV C or REV B. Based on that reading the
> drivers could set the pin muxing accordingly to make the pins be in
> the correct mode. No functionality is lost because of this change.
> Below are the affected signals:
>
> *
>
> CURRENT ASSIGNMENTS
>
> **
>
> EXP Pin 4
>
> *McBSP3_DX UART2_CTS GPIO_140 *OMAP Pin AE6*
>
> *EXP PIN 6 *McBSP3_CLKX UART2_TX
> GPIO_142 *OMAP Pin AF5*
>
> *
>
> EXP PIN 8 McBSP3_
>
> *FSX UART2_RX GPIO_143 *OMAP Pin AE5*
>
> *NEW ASSIGNMENTS*
> **
> *EXP PIN 4* UART2_CTS McBSP3_DX gpt9_pwm_evt
> GPIO_144 *OMAP Pin *AB26
>
> *EXP PIN 6 *UART2_TX McBSP3_CLKX gpt11_pwm _evt
> GPIO_146 *OMAP Pin AA25*
>
> *
>
> EXP PIN 8 UART2_RX
>
> *McBSP3_FSX gpt8_pwm_evt GPIO_147 *OMAP Pin AD25*
>

Preston Wilson

unread,
Dec 16, 2008, 1:29:45 PM12/16/08
to Beagle Board
I would also like more I/O, but I would also like to see the existing
expansion header kept in its current location. This is for a selfish
reason, but I am probably not the only one doing this. I am building
an expansion card that mates with that expansion header. I actually
received the first prototypes of the board I am building from the PC
fabrication company this morning.

The proposed pin changes look good to me and, checking the board rev
in software and doing the pin configuration based on the results works
for me.

-Preston

Preston Wilson

unread,
Dec 16, 2008, 1:35:26 PM12/16/08
to Beagle Board
On Dec 16, 1:29 pm, Preston Wilson <rpwilso...@gmail.com> wrote:
> I would also like more I/O, but I would also like to ...

That should have read: I would like more I/O options, ...

meaning that I like the idea of getting the option of using PWM.

-Preston

Gerald Coley

unread,
Dec 16, 2008, 1:40:13 PM12/16/08
to beagl...@googlegroups.com
Actually, you are getting more I/O options via the LCD expansion headers. If you look at the pin muxing, I think you will find that some of these signals have alternate pin functions, like GPIO and UART1.
 
Gerald

emeb

unread,
Dec 16, 2008, 2:45:16 PM12/16/08
to Beagle Board


On Dec 16, 11:40 am, "Gerald Coley" <ger...@beagleboard.org> wrote:
> Actually, you are getting more I/O options via the LCD expansion headers. If
> you look at the pin muxing, I think you will find that some of these signals
> have alternate pin functions, like GPIO and UART1.

Indeed! Table 7-4 of spruf98b indicates that GPIO 66-90, UARTs 1 & 3
and McSPI3 are all available as alternate modes of the DSS pins. If
you power down the DVI framer (via GPIO 170) then these would be
available for other purposes. Nice.

Eric

Gerald Coley

unread,
Dec 16, 2008, 2:50:59 PM12/16/08
to beagl...@googlegroups.com
This is correct. Sort of a "freebie".
 
Gerald

Søren Steen Christensen

unread,
Dec 16, 2008, 3:20:34 PM12/16/08
to beagl...@googlegroups.com

Hi Gerald,

 

Will the LCD expansion connector be a pin-header/connector or only a set of test points on which users can solder their own wires in case needed?

 

From the initial picture: http://beagleboard.googlegroups.com/attach/2e82c3ed6061d9d2/Beagle_exp_LCD_RevC.JPG?gda=H2bt6EUAAACmgoNvonPc5qbQ6Ev-XRhNl1WxzKcR5wz-N7NembB3jHQVhVzKDTcmciFORS7UcUyO3f1cykW9hbJ1ju6H3kglGu1iLHeqhw4ZZRj3RjJ_-A&view=1&part=4 I think it looks like a 1.27 mm spaced connector, but could fear that the holes in the pads are too small to mount any real connector in them?

 

Best regards

  Søren


No virus found in this incoming message.
Checked by AVG - http://www.avg.com
Version: 8.0.176 / Virus Database: 270.9.18/1851 - Release Date: 16-12-2008 08:53

Gerald Coley

unread,
Dec 16, 2008, 3:27:01 PM12/16/08
to beagl...@googlegroups.com
It is two 20 pin 1.27mm pitch headers. Connectors are available.
 
Gerald

John (USP)

unread,
Dec 16, 2008, 4:46:08 PM12/16/08
to beagl...@googlegroups.com

If you tried to install one of these connectors, you will know they are very difficult to solder and the pins are very soft, so they bend really easy. I would have used a ZIF connector, which is far easier to install and if you used the pin layout of the PSP1000 display, you could connect a low cost LCD without the need for an adapter.

 


Regards,


 

<br

Gerald Coley

unread,
Dec 16, 2008, 4:51:40 PM12/16/08
to beagl...@googlegroups.com
Have you ever tried hand solder on a ZIF connector to a PCB? Now that is tough!
 
Gerald

Keith Williams

unread,
Dec 16, 2008, 4:51:49 PM12/16/08
to beagl...@googlegroups.com
Unless the LCD you referred to takes 1.8 v logic levels, you'll need an
adapter anyway.

-Keith

John (USP) wrote:
>
> If you tried to install one of these connectors, you will know they
> are very difficult to solder and the pins are very soft, so they bend
> really easy. I would have used a ZIF connector, which is far easier to
> install and if you used the pin layout of the PSP1000 display, you
> could connect a low cost LCD without the need for an adapter.
>
>
>
>
> Regards,
>
>
>
>
> *From:* beagl...@googlegroups.com
> [mailto:beagl...@googlegroups.com] *On Behalf Of *Gerald Coley
> *Sent:* Tuesday, December 16, 2008 12:27 PM
> *To:* beagl...@googlegroups.com
> *Subject:* [beagleboard] Re: REV C Changes
>
>
>
> It is two 20 pin 1.27mm pitch headers. Connectors are available.
>
>
>
> Gerald
>
>
>
>
>
> On Tue, Dec 16, 2008 at 2:20 PM, Søren Steen Christensen
> <sorensch...@stofanet.dk <mailto:sorensch...@stofanet.dk>>
> wrote:
>
> Hi Gerald,
>
>
>
> Will the LCD expansion connector be a pin-header/connector or only a
> set of test points on which users can solder their own wires in case
> needed?
>
>
>
> From the initial picture:
> http://beagleboard.googlegroups.com/attach/2e82c3ed6061d9d2/Beagle_exp_LCD_RevC.JPG?gda=H2bt6EUAAACmgoNvonPc5qbQ6Ev-XRhNl1WxzKcR5wz-N7NembB3jHQVhVzKDTcmciFORS7UcUyO3f1cykW9hbJ1ju6H3kglGu1iLHeqhw4ZZRj3RjJ_-A&view=1&part=4
> <http://beagleboard.googlegroups.com/attach/2e82c3ed6061d9d2/Beagle_exp_LCD_RevC.JPG?gda=H2bt6EUAAACmgoNvonPc5qbQ6Ev-XRhNl1WxzKcR5wz-N7NembB3jHQVhVzKDTcmciFORS7UcUyO3f1cykW9hbJ1ju6H3kglGu1iLHeqhw4ZZRj3RjJ_-A&view=1&part=4>
> I think it looks like a 1.27 mm spaced connector, but could fear that
> the holes in the pads are too small to mount any real connector in them?
>
>
>
> Best regards
>
> Søren
>
>
>
>
>
> *Fra:* beagl...@googlegroups.com
> <mailto:beagl...@googlegroups.com>
> [mailto:beagl...@googlegroups.com
> <mailto:beagl...@googlegroups.com>] *På vegne af *Gerald Coley
> *Sendt:* 16. december 2008 20:51
> *Til:* beagl...@googlegroups.com <mailto:beagl...@googlegroups.com>
> *Emne:* [beagleboard] Re: REV C Changes
>
>
>
> This is correct. Sort of a "freebie".
>
>
>
> Gerald
>
>
>
>
>
> On Tue, Dec 16, 2008 at 1:45 PM, emeb <ebrom...@gmail.com
> <mailto:ebrom...@gmail.com>> wrote:
>
>
>
>
> On Dec 16, 11:40 am, "Gerald Coley" <ger...@beagleboard.org
> <mailto:ger...@beagleboard.org>> wrote:
> > Actually, you are getting more I/O options via the LCD expansion
> headers. If
> > you look at the pin muxing, I think you will find that some of these
> signals
> > have alternate pin functions, like GPIO and UART1.
>
> Indeed! Table 7-4 of spruf98b indicates that GPIO 66-90, UARTs 1 & 3
> and McSPI3 are all available as alternate modes of the DSS pins. If
> you power down the DVI framer (via GPIO 170) then these would be
> available for other purposes. Nice.
>
> Eric
>
>
>
> No virus found in this incoming message.
> Checked by AVG - http://www.avg.com <http://www.avg.com/>

John (USP)

unread,
Dec 16, 2008, 5:01:00 PM12/16/08
to beagl...@googlegroups.com

Hi Gerald,

 

Actually, it isn’t that difficult. Use liquid flux and fine solder wick. Apply liquid flux, solder all the pins. Don’t worry about shorts, Use fine solder wick to remove the shorts. Simple.

 


Regards,


 

<br

Gerald Coley

unread,
Dec 16, 2008, 5:05:07 PM12/16/08
to beagl...@googlegroups.com
Maybe somone will put together an adapter kit with the level shifters and power regulators.
 
Gerald

John (USP)

unread,
Dec 16, 2008, 5:05:03 PM12/16/08
to beagl...@googlegroups.com
Good point. Still, the ZIF connector is more robust and the adapter can be
placed anywhere, whereas the 1.27 header only allows the adapter board to be
placed behind the BeagleBoard.


Regards,


> -----Original Message-----
> From: beagl...@googlegroups.com
> [mailto:beagl...@googlegroups.com] On Behalf Of Keith Williams
> Sent: Tuesday, December 16, 2008 1:52 PM
> To: beagl...@googlegroups.com

Gerald Coley

unread,
Dec 16, 2008, 5:08:12 PM12/16/08
to beagl...@googlegroups.com
Actually, behind the Beagle is a safe place to put it. That way it does not interfere with the expansion cards.
 
Gerald

John (USP)

unread,
Dec 16, 2008, 5:24:57 PM12/16/08
to beagl...@googlegroups.com

Hi Gerald,

 

Unless you are trying to fit this into a specific enclosure. The ZIF solution gives you the flexibility to put the adaptor/LCD/protoboard anywhere you want. Anyway, it sounds to me you are too far along to make a change at this time, so this isn’t really a problem. I will just make a 1.27mm header to ZIP adapter. Simple solution and everyone is happy.

 


Regards,


Gerald Coley

unread,
Dec 16, 2008, 5:29:48 PM12/16/08
to beagl...@googlegroups.com
We are definitely too far along. We have people working on adapter boards and the Rev C protos are up and running. Thanks for the input!
 
Gerald

Sean D'Epagnier

unread,
Dec 17, 2008, 1:00:55 AM12/17/08
to beagl...@googlegroups.com
Hi,

I already have an adapter board for the zif connector that is on the
way. I also have an adapter board that does level translation to
whatever voltage you need, most lcds don't want 1.8v, so most likely
the zif connector wouldn't go on the beagle without additional level
translators.

The zif connectors are probably harder to solder than the connectors
proposed, they are spaced .5mm

Sean

On 12/16/08, Gerald Coley <ger...@beagleboard.org> wrote:
> We are definitely too far along. We have people working on adapter boards
> and the Rev C protos are up and running. Thanks for the input!
>
> Gerald
>
>
>
> On Tue, Dec 16, 2008 at 4:24 PM, John (USP) <jsyn...@us-power.com> wrote:
>
>> Hi Gerald,
>>
>>
>>
>> Unless you are trying to fit this into a specific enclosure. The ZIF
>> solution gives you the flexibility to put the adaptor/LCD/protoboard
>> anywhere you want. Anyway, it sounds to me you are too far along to make a
>> change at this time, so this isn't really a problem. I will just make a
>> 1.27mm header to ZIP adapter. Simple solution and everyone is happy.
>>
>>
>>
>>
>> Regards,
>>
>>
>>
>>
>> *From:* beagl...@googlegroups.com [mailto:beagl...@googlegroups.com]
>> *On Behalf Of *Gerald Coley
>> *Sent:* Tuesday, December 16, 2008 2:08 PM

Terrence

unread,
Dec 18, 2008, 3:24:32 PM12/18/08
to beagl...@googlegroups.com
I would wish that an extra set of along side each location of the GPIO ,
LCD, JTAG & +5V GND Power Sip pin holes could be masked off and allow for
inexpensive 2 & 4 Layer expansion / interface board . cost is way more to
get custom cables to route in an enclosure... and take to much time to
assemble..

-T
----- Original Message -----
From: "emeb" <ebrom...@gmail.com>
To: "Beagle Board" <beagl...@googlegroups.com>
Sent: Tuesday, December 16, 2008 10:15 AM
Subject: [beagleboard] Re: REV C Changes



Gerald Coley

unread,
Dec 18, 2008, 5:37:21 PM12/18/08
to beagl...@googlegroups.com
The LCD and Expansion already allow for add-on board as does the JTAG header. Having an extra set of holes where there are already holes does not seem to add a lot of value. what exactly are you wanting to do that the current holes won't accomplish?
 
Thank you!
 
Gerald

Dirk Behme

unread,
Dec 29, 2008, 5:53:24 AM12/29/08
to beagl...@googlegroups.com
Gerald Coley wrote:
> We are looking to add some PWM signals to the expansion connector. This
> will be valuable for robotics and other functions. We are considering
> two different ways to accomplish this. Our goal is to make this as
> non-disruptive as possible and to have a zero cost impact.
>
> The current plan is to replace the following pins on the OMAP3530 with
> different pins that will not change the available functions on those
> expansion pins, but it will add the PWM signals to them. One side affect
> is that the pin muxing will change for these pins on the Rev C. There
> are ID pins on the REV C board that will allow the SW to identify if the
> board is a REV C or REV B.

Already any details available how this identification can be done?
I.e. register and value(s)?

> Based on that reading the drivers could set
> the pin muxing accordingly to make the pins be in the correct mode. No
> functionality is lost because of this change. Below are the affected
> signals:

*CURRENT ASSIGNMENTS*

* EXP Pin 4:
McBSP3_DX UART2_CTS GPIO_140
OMAP Pin:AE6

* EXP PIN 6:
McBSP3_CLKX UART2_TX GPIO_142
OMAP Pin: AF5

* EXP PIN 8:
McBSP3_FSX UART2_RX GPIO_143
OMAP Pin: AE5

*NEW ASSIGNMENTS*

* EXP PIN 4:
UART2_CTS McBSP3_DX gpt9_pwm_evt GPIO_144
OMAP Pin: AB26

* EXP PIN 6:
UART2_TX McBSP3_CLKX gpt11_pwm _evt GPIO_146
OMAP Pin: AA25

* EXP PIN 8:
UART2_RX McBSP3_FSX gpt8_pwm_evt GPIO_147
OMAP Pin: AD25

Is this the configuration now used with revision C1?

Dirk

Gerald Coley

unread,
Dec 29, 2008, 7:55:47 AM12/29/08
to beagl...@googlegroups.com
We are still testing, but there are two GPIO pins, GPIO_171 and GPIO_172. As long as both pins are grounded, then the board is a Rev C2.
 
The changes we ended up with for Rev C2 are:
 
Pin 4 added GPT9_PWMEVT......................OMAP3530 pin AB26
Pin 6 added GPT10_PWMEVT.....................OMAP3530 pin AB25
Pin 10 added GPT11_PWMEVT...................OMAP3530 pin AA25
 
Gerald

Reply all
Reply to author
Forward
0 new messages