Designing in the SX48BD and Going from BS2P/PBASIC to SX BASIC

Waveman

Hello,

I was unable to get the proper answers to the following questions from Parallax Tech Support, and·appreciate it if that someone can answer:

1) We have used the BS2P to prototype our wireless device and want to know when designing our pcb with the SX48BD, should we follow the BS2P schematic reference? We are hoping to copy the schematic right into our wireless device design.

2) Parallax sells both the SX48BD with PBASIC Interpreter and the SX48BD that can be used with the SX/B BASIC compiler, is this correct?

3) Are the only main differences between SX28 and SX48 the·number of I/O pins?

4) As mentioned, we've prototyped our design with the BS2P and PBASIC. If we integrate in the SX48DB to our design, should we·be programming in PBASIC or hould we use the SX/B BASIC compiler instead?

(Our s/w guy prefers using SX/B and I assume only advantage of BS2p/PBASIC is simplicity).

4) How much effort to take our PBASIC·code and convert to SX/B?

WaveMan

PJMonty

Waveman,

1 - I'm not real versed in Basic Stamp-ville, but I'm pretty sure the answer is, "No" with regards to the schematic. The Basic Stamp has other components (such as EEPROM to run programs) that the SX48 doesn't need.

2 - The BS2P is a complete circuit on a PCB that has an SX chip along with EEPROM and some other stuff. The SX48BD is simply a naked SX chip, period. You need to design an SX48 into a circuit with the (minimal) required support stuff (clock source, pull-up resistor on the MCLR line, etc), whereas with the BS2P you pretty much add electricity and start running. The SX48 can be programmed using SX/B, but it requires an SX-Key to actually download and debug the chip. The BS2P just needs a serial cable.

3 - More pins and double the internal space for storing programs.

4 - SX/B.

5 - Others will have more input on this as I program in assembly. However, I know that a lot of effort was put into making the languages compatible wherever possible.

Thanks,
PeterM

Bean

1-If you want to use PBASIC then buy this http://www.parallax.com/detail.asp?product_id=PBASIC48W/P24
and layout your board according to the schematic for the BS2P. If you want to use SX/B, then buy this http://www.parallax.com/detail.asp?product_id=SX48BD-G·and layout your board like the SX48 prototype.

2-Yes, see #1

3-More I/O pins, double the RAM, double the code space. SX48 has two hardware timers.

4-See #1

5-It depends on the program. Some translate very easily. Some need quite a bit more work.

Bean.


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Waveman

Thank you both for the prompt reply.

I understand the need for an SX Tech Tool Key for programming the SX chip and was wondering what the best resources are·to·integrate in the SX to our design? Recommended books on·designing in the SX chip?

The Hitt Consulting Site says "knowledge of oscillator speeds, page switching, and managing an interrupt service routine will be necessary to get the most performance from an SX chip." Any books requested above have this info?

Thanks,

WaveMan

Bean

There are many books free for download from here http://www.parallax.com/sx/downloads.asp

Bean.

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Waveman

Bean, thanks.

WM

Bean

Oh and here is a GOOD one http://www.parallax.com/dl/docs/prod/sx/PracticalSXB.pdf

Bean.

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I know what I know, don't confuse me with the facts...
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