Penguin 2px motherboard questions.

Martin_H · 2012-04-04 13:00

Off the wall question for a possibly off the wall project. I have two penguin robots. One I assembled and use, the other as been sitting unassembled as I don't need two walking about. But I've always had plans for the BS2 px motherboard as it's small and includes a lot of features. One question though.

I've run an AVR directly off three AA batteries and I was wondering if I would run the BS2 px directly off three LR44 (1.5 v button cell) batteries? Looking at the OEM chip documents I think it should run fine between 3-5 volts.

I know the BS2 can't directly output IR signals, but the 2px is considerably faster. Can it output IR control signals?

I need to know the connections for the ribbon cable, but I looked on the Parallax site and all the pages for the Penguin are gone. Does anyone know the ribbon cable pin outs and inputs?

Zoot · 2012-04-04 13:25

Martin_H wrote: »

Off the wall question for a possibly off the wall project. I have two penguin robots. One I assembled and use, the other as been sitting unassembled as I don't need two walking about. But I've always had plans for the BS2 px motherboard as it's small and includes a lot of features. One question though.

I've run an AVR directly off three AA batteries and I was wondering if I would run the BS2 px directly off three LR44 (1.5 v button cell) batteries? Looking at the OEM chip documents I think it should run fine between 3-5 volts.

Keep in mind the brownout setting on Stamps is about 4.2v -- below that and the chip will hold itself in reset.

Martin_H wrote: »

I know the BS2 can't directly output IR signals

Both a BS2 and BS2px can. Not sure what you're describing.

Martin_H · 2012-04-04 13:34

Zoot wrote: »

Keep in mind the brownout setting on Stamps is about 4.2v -- below that and the chip will hold itself in reset.

Is this part of the chip itself or in the module's voltage regulator circuitry? The Penguin has the regulator circuits in the backpack section and I'm only planning to use the board that is on top of the penguin.

Zoot wrote: »

Both a BS2 and BS2px can. Not sure what you're describing.

I mean modulate a 38 KHz IR signal to encode a TV remote signal.

RobotWorkshop · 2012-04-04 13:46

As I recall the Brownout is a configurable setting in the SX48 processor and that the OEM BASIC Stamp chips come with that preset at 4.2V. You could try contacting Parallax directly to see if that is the case with the ones used on the Penguin board or not.

Robert

Zoot · 2012-04-04 15:00

What Robert said -- brownout circuitry is onboard the SXes used on the higher performance Stamps. This is set permanently in the firmware burned into the SX that "makes" it a Stamp.

IR frequency modulation on the Stamp is done all the time -- using FREQOUT. The Penguin has onboard IR emitters to do just that. See Robotics with the Boe-bot for lots of examples.

Martin_H · 2012-04-04 16:09

Zoot wrote: »

IR frequency modulation on the Stamp is done all the time -- using FREQOUT. The Penguin has onboard IR emitters to do just that. See Robotics with the Boe-bot for lots of examples.

OK, thanks for the brown out information. I think I need to contact Parallax about the ribbon cable and their statement on the voltage for the 2px in the Penguin.

What I mean about modulation isn't just emitting a 38 kHz signal, but modulating TV remote codes into the signal. This is done via PWM of the 38 kHz signal itself. The Andy Lindsey book on Boe-bot IR control talks about how the regular stamp isn't fast enough and uses an external 555 timer to generate a signal while the stamp modulated it. Now this would work with the 2px, but I was wondering it it was fast enough to do it directly like an AVR can.

The reason I am asking is I want to fit a circuit into a really tight spot and the Penguin control board is all surface mount and has everything I need.

bee_man · 2012-04-04 16:23

Have you looked under the Penguin resources on the robotics thread?

"]http://forums.parallax.com/showthread.php?97415-PENGUIN-ROBOT-Remote-Controller-the-Code-is-Here!"]

Martin_H · 2012-04-04 16:26

Thanks, but I want to do it the other way around. I want to transmit the codes, not receive them.

Phil Pilgrim (PhiPi) · 2012-04-04 17:46

Martin,

You might consider the MoBoStamp-pe. It uses a BS2pe chip and will run at any voltage between 3.3V and 5V on Vdd; up to 9V on Vin. It also has a pair of AVR coprocessors, each of which has two PWM channels capable of outputting a steady 37.5 KHz carrier. With special programming, they could also perform the modulation in response to an input. The board's dimensions are 2.75" x 1.35". I'm not sure how that compares with the Penguin board, though. The only downside is that Parallax is currently out of stock on the MoBos.

-Phil

Martin_H · 2012-04-04 18:09

The MoBoStamp-pe would probably be ideal for this project, but it is sort of a lark and I don't want to do it on a big budget.

What I am thinking of doing is going down to Radio Shack and picking up one of those Hex bug spiders (sorry Jamie) and then trying to reverse engineer its IR control protocol. If I figure it out I could then use the Penguin board as a control board with IR being the interface protocol. I would need a really compact power source hence the three watch battery idea. The Penguin board has all kinds of sensors on it so I could get an instant hexapod robot.

Martin_H · 2012-04-05 07:27

This looks easier to do than I first thought. Here's a site where they didn't even bother to reverse engineer the IR protocol. They just wired a microcontroller to the unit's IR remote:

http://e2e.ti.com/group/msp430launchpad/m/project/479881.aspx

Penguin 2px motherboard questions.

Comments