another quick Holtek question
Archiver
Posts: 46,084
Hello,
I was experimenting with a holtek encoder and
decoder and something happens that I'm not sure about.
I have a stamp connected to the encoder where I place
some combination of values on the D pins, then I bring
the Transmit Enable(TE) high to send the message.
I'm using an rf tx and rx.
This works ok, but when I only bring the TE high, without
any message, (that is, not setting anything on the data pins,
neither high or low) somehow all the decoder message pins are high
after the decoder recieves a message.
So, why? Am I sending this to the decoder, because the stamp
pins are normally high? If they are not set to something? Or is the decoder
doing this when it receives an empty message after the TE is set high.
Thanks in advance.
I was experimenting with a holtek encoder and
decoder and something happens that I'm not sure about.
I have a stamp connected to the encoder where I place
some combination of values on the D pins, then I bring
the Transmit Enable(TE) high to send the message.
I'm using an rf tx and rx.
This works ok, but when I only bring the TE high, without
any message, (that is, not setting anything on the data pins,
neither high or low) somehow all the decoder message pins are high
after the decoder recieves a message.
So, why? Am I sending this to the decoder, because the stamp
pins are normally high? If they are not set to something? Or is the decoder
doing this when it receives an empty message after the TE is set high.
Thanks in advance.
Comments
These internal pull-up resistors will cause each data-input
pin to default to logic 1 when not connected to logic 0.
With TE active + no inputs connected to ground, the data
transferred will be all logic 1s.
Bruce
webmaster@r...
http://www.rentron.com
=================================
Remote Control For The Stamp
http://www.rentron.com/rf_remote_control.htm
==================================
Original Message
From: "rad0" <rden25@m...>
To: "Stampers!" <basicstamps@egroups.com>
Sent: Monday, October 02, 2000 6:29 PM
Subject: [noparse][[/noparse]basicstamps] another quick Holtek question
| Hello,
|
| I was experimenting with a holtek encoder and
| decoder and something happens that I'm not sure about.
|
| I have a stamp connected to the encoder where I place
| some combination of values on the D pins, then I bring
| the Transmit Enable(TE) high to send the message.
| I'm using an rf tx and rx.
|
| This works ok, but when I only bring the TE high, without
| any message, (that is, not setting anything on the data pins,
| neither high or low) somehow all the decoder message pins are high
| after the decoder recieves a message.
|
| So, why? Am I sending this to the decoder, because the stamp
| pins are normally high? If they are not set to something? Or is the decoder
| doing this when it receives an empty message after the TE is set high.
|
| Thanks in advance.
|
|
|
|
|
I see that you are connected to the Rentron place
where I actually got the radio recently. And I was
wondering what brand this thing is? It's not the ming
it's the other one. RF
And another thing, I have the data sheets for these
Holtek chip, and I can't seem to find anywhere on
them this info about internal pull up resisters? Is it
there or have you gotten this on some other source?
Anyway, thanks again.
Rick
Original Message
From: "Bruce" <breyno2@r...>
To: <basicstamps@egroups.com>
Sent: Tuesday, October 03, 2000 10:46 AM
Subject: Re: [noparse][[/noparse]basicstamps] another quick Holtek question
> The HT-12E data input-pins have internal pull-up resistors.
> These internal pull-up resistors will cause each data-input
> pin to default to logic 1 when not connected to logic 0.
>
> With TE active + no inputs connected to ground, the data
> transferred will be all logic 1s.
>
> Bruce
> webmaster@r...
> http://www.rentron.com
>
> =================================
> Remote Control For The Stamp
> http://www.rentron.com/rf_remote_control.htm
> ==================================
>
>
>
Original Message
> From: "rad0" <rden25@m...>
> To: "Stampers!" <basicstamps@egroups.com>
> Sent: Monday, October 02, 2000 6:29 PM
> Subject: [noparse][[/noparse]basicstamps] another quick Holtek question
>
>
> | Hello,
> |
> | I was experimenting with a holtek encoder and
> | decoder and something happens that I'm not sure about.
> |
> | I have a stamp connected to the encoder where I place
> | some combination of values on the D pins, then I bring
> | the Transmit Enable(TE) high to send the message.
> | I'm using an rf tx and rx.
> |
> | This works ok, but when I only bring the TE high, without
> | any message, (that is, not setting anything on the data pins,
> | neither high or low) somehow all the decoder message pins are high
> | after the decoder recieves a message.
> |
> | So, why? Am I sending this to the decoder, because the stamp
> | pins are normally high? If they are not set to something? Or is the
decoder
> | doing this when it receives an empty message after the TE is set high.
> |
> | Thanks in advance.
> |
> |
> |
> |
> |
>
>
>
>
| I see that you are connected to the Rentron place
| where I actually got the radio recently. And I was
| wondering what brand this thing is? It's not the ming
| it's the other one. RF
The TWS/RWS RF modules are manufactured in Taiwan
by a company called Wenshing.
| And another thing, I have the data sheets for these
| Holtek chip, and I can't seem to find anywhere on
| them this info about internal pull up resisters? Is it
| there or have you gotten this on some other source?
In the Holtek data sheet refer to the section that shows
diagrams of (approximate internal connections). This
shows the input pull-up resistors.
You can use these RF modules with the Basic Stamp
serin serout commands also for really simple RF remote
control systems without using encoder/decoder ICs.
Check out the Robot project by Rob Arnold that uses the
TWS/RWS RF combination to create an RF joystick for
controlling his robot at: http://www.rentron.com/ruf-bot.htm
The project uses PicBasic, but can be very easily adapted to
the Stamp.
Bruce
webmaster@r...
http://www.rentron.com
=================================
Remote Control For The Stamp
http://www.rentron.com/rf_remote_control.htm
==================================
OK, that's my problem, I did see
the diagram, but I wasn't able to read
the thing.
>
> | And another thing, I have the data sheets for these
> | Holtek chip, and I can't seem to find anywhere on
> | them this info about internal pull up resisters? Is it
> | there or have you gotten this on some other source?
>
> In the Holtek data sheet refer to the section that shows
> diagrams of (approximate internal connections). This
> shows the input pull-up resistors.
>
Are you refering to the 'cmos out' diagram? Does
this diagram supply the resistor info you're talking
about.
It looks like a logic diagram, and if I remember correctly
an invert symbol, but the rest is gone from my memory.
As you can see, this is a foreign language to me,
for the moment.
Thanks very much!
Rick
> You can use these RF modules with the Basic Stamp
> serin serout commands also for really simple RF remote
> control systems without using encoder/decoder ICs.
>
> Check out the Robot project by Rob Arnold that uses the
> TWS/RWS RF combination to create an RF joystick for
> controlling his robot at: http://www.rentron.com/ruf-bot.htm
>
> The project uses PicBasic, but can be very easily adapted to
> the Stamp.
>
> Bruce
> webmaster@r...
> http://www.rentron.com
>
> =================================
> Remote Control For The Stamp
> http://www.rentron.com/rf_remote_control.htm
> ==================================
>
>
>
>
>
>
| Are you refering to the 'cmos out' diagram? Does
| this diagram supply the resistor info you're talking
| about.
Yes. This shows the internal connections for each pin.
| It looks like a logic diagram, and if I remember correctly
| an invert symbol, but the rest is gone from my memory.
That's the one. It shows the pull-up resistors on the
CMOS input-pins.
| As you can see, this is a foreign language to me,
| for the moment.
We all have to start somewhere, and with the tallent available
on this list, it's only a matter of time until you have
plenty of answers to those seemingly foreign doo-dadds...[noparse]:o[/noparse]]
Bruce
webmaster@r...
http://www.rentron.com
=================================
Remote Control For The Stamp
http://www.rentron.com/rf_remote_control.htm
==================================