Re: [Oap-discuss] issue reading odometry

[Scott C. <rob...@gm...>]

Hi Dafydd,

The gEDA gsch2pcb tool relies on the schematic pins and network to create
the pcb traces.

I've created a new 78HC74 symbol and updated the mcm schematic.   Would you
please review the new version?  The pdf and image formats are available
from the community wiki:

http://www.openautomaton.org/index.php/MCM

Thanks for your help.
--scott


On Tue, Nov 19, 2013 at 1:14 AM, Dafydd Walters <daf...@gm...>wrote:

> Hi Scott,
>
> Yes, pin 14 should be connected to +5V and pin 7 should be connected to
> GND (0V).
>
> It's customary not to show the power supply pin connections of ICs on
> circuit schematics to avoid clutter, but you mustn't forget the power when
> laying out the PCB :-)
>
> Regards,
> Dafydd.
>  On 19 Nov 2013 02:35, "Scott Crawford" <rob...@gm...> wrote:
>
>> Hi Dafydd,
>>
>> I'm not receiving valid odometry data from the "read_odometry" function
>> in oap-motor.c.  However, the i2s_smbus_read_block returns exactly 5 bytes.
>>
>> Can  you tell me if pin 14, Vcc, on the 74HC74 (U3 and U4) need to be
>> connected to +5V?
>>
>> Some references:
>> 1. 74HC74 datasheet for a 74HC74 with preset and clear:
>> http://www.fairchildsemi.com/ds/MM/MM74HC74A.pdf
>>
>> 2. odometry input signals
>> http://www.openautomaton.org/index.php/MCM
>>
>> 3. Your original oap 0.1 schematic and my rework for pcb design are here:
>> http://www.openautomaton.org/index.php/Schematics
>>
>> Thanks for your help.
>> --scott
>>
>>
>>
>> ------------------------------------------------------------------------------
>> Shape the Mobile Experience: Free Subscription
>> Software experts and developers: Be at the forefront of tech innovation.
>> Intel(R) Software Adrenaline delivers strategic insight and game-changing
>> conversations that shape the rapidly evolving mobile landscape. Sign up
>> now.
>>
>> http://pubads.g.doubleclick.net/gampad/clk?id=63431311&iu=/4140/ostg.clktrk
>> _______________________________________________
>> Oap-discuss mailing list
>> Oap...@li...
>> https://lists.sourceforge.net/lists/listinfo/oap-discuss
>>
>>
>
> ------------------------------------------------------------------------------
> Shape the Mobile Experience: Free Subscription
> Software experts and developers: Be at the forefront of tech innovation.
> Intel(R) Software Adrenaline delivers strategic insight and game-changing
> conversations that shape the rapidly evolving mobile landscape. Sign up
> now.
> http://pubads.g.doubleclick.net/gampad/clk?id=63431311&iu=/4140/ostg.clktrk
> _______________________________________________
> Oap-discuss mailing list
> Oap...@li...
> https://lists.sourceforge.net/lists/listinfo/oap-discuss
>
>