Is my design workable?

New1976

Hi All,

I'm currently doing my project. I have drafted out the design of the circuit which involved the RF Transmitter module, Max232 with RS232.

Need your gyu·advise, is my design workable?

I need to carify with you on the Wireless RF Module Manual as attached below and was downloaded from the parallax website.

Following are enquires:

1. On the Manual under the header "Transmitter hook-up" at point 3: Connect all pins labeled GND to ground. (Make sure the ground is common with your Basic Stamp.)

Question : I using the normal ground from the Max232 board, any concern?



Please advise

Regards,

New1976

Jon Williams

I've not used those modules, but think that there are two issues you need to address:

(1) You need to connect the TX pin of the transmitter to the receive output of the RS-232 circuit (so that what you receive from the PC gets transmitted via RF).

(2) In this article (http://www.parallax.com/dl/docs/article/Roboto.pdf) it shows the device baudmode as inverted -- so you may need to add an inverter between the RS-232 connection and the module (you can do it with a simple emiiter-follower circuit).

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Jon Williams
Applications Engineer, Parallax

New1976

Hi Jon,

Thanks for the advise. Below are the my revised copy. However i'm not very sure why i need to add an inverter between the RS-232 connection and the module. Could you please advise me in this area.

Just simple introduction of what i'm going to achieve for this project.

I'm trying to download the Basic Stamp source code from PC·into the BOE Bot Robot that built with micrcontroller in wireless instead of serial programming cable.

As you see from my attached file, the RS232 port is connected to the PC. And they are another RF module which is receiver will plug into the breadboard at the BOE BOT robot kit.

Please advise an inverter between the RS-232 connection and the module and the project.

Regards,

NEw1976

Jon Williams

I think you still need an inverter between the MAX232 and the RF module. The reason is that the RF module seems to work in inverted mode; this means a start bit goes from 0v to 5v -- whereas the output from the MAX232 will go from 5v to 0v (true mode) for the start bit.·

But don't take my word for anything ... if you've got the parts hook it up (new schematic) and give it a try.· You could create a simple program on the BASIC Stamp end that simply sends the value received to some LEDs (though a serial LCD would be a better output device because you would see the characters coming from the remote·keyboard).

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Jon Williams
Applications Engineer, Parallax

New1976

Hi Jon,

Thanks for your guidance.

So basically i only need to add the inverter device between the RF transmitter module of the voltage source and the max232.

I'm just a bit curious, how's about the RF Receiver module? This module was actually plug into the breadboard·at the BOE BOT robot kit. From the schematic diagram of the BOE board, i don't see any invevter.However in the manual, it instructed us to plug in the RF receiver. why's that so?

Could you please advice me, why the RF receiver module doesn't need a inverter?

Regards,

New1976









.

Jon Williams

Because the RF receiver is connecting directly to the BASIC Stamp which can be more flexible in how it gets serial data; you can configure it for True or Inverted, whereas the PC is always True mode.

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Jon Williams
Applications Engineer, Parallax

New1976

Hi Jon,

Thanks for·your·advise. I had summaries it and learned from what you have taught me. The drawing is the revised copy.

Kindly let me know if·i interpreter wrongly.

Appreciate your help.

Regards,
New1976

Jon Williams

Looks fine ... have you hooked it up? Theory is one thing; practical experience is quite another.

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Jon Williams
Applications Engineer, Parallax

New1976

hi Jon,

Thanks for your advise. I will try to connect ASAP by this weeks. I will keep you update the results.

So stay tune.

FYI.. i have also attached the·draft final·copy of the connection of the·RF transmitter & Max232 tapping the power source from the 5V voltage adapter.

let me know if any concern,

Thanks.

Regards,

New1976

New1976

Hi Jon,

I have completed the setup of the hardware for the transmitter with the circuit as i provided the previously. However i got a bit problem which i need your advise. As you know i'm using the RF modules to download the BS2 in wireless mode.

For the RF transmitter side, how i do i write the program as i not using any of the basic stamp? In order words, how's to i used the Serout instruction?

Please advise.

New1976



·

Jon Williams

My best advice is to read the manual; SEROUT is fully explained. For an experiment-oriented text, download "What's A Microcontroller?" -- it's very good.

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Jon Williams
Applications Engineer, Parallax

New1976

Hi Jon.

I need to confirm with you again. Even on my RF transmitter side modules which·i'm not using any of the Basic·Stamp 2, i still can write the program to download to my BS2 using serout. am i right to say that?



Regards,

Jon Williams

You can communicate with your BASIC Stamp using SERIN and SEROUT, but you can't download a new program to it. If you want to do downloading (very advanced process), you can get the information from our web site.

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Jon Williams
Applications Engineer, Parallax

New1976

Hi Jon,

Could you direct me where is the website of teaching how to used the SEROUT when i don't have BS2 on the RF transmitter?

Please help.



Regards,

New1976

Jon Williams

Please open the manual. If you don't have a printed version, click on the Help icon in the BASIC Stamp editor.

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Jon Williams
Applications Engineer, Parallax

Paul Baker

Here is a direct link to the page on SEROUT in the online Basic Stamp Users Manual. You can manually navigate there by going to www.parallax.com hover over·"Downloads" in the menu bar, click on "Documentation", then click on the Download folder for·Basic Stamp Manual Version 2.1.

New1976

Hi Jon·and everyone,

The problem now i'm facing is that·i'm trying to create a communication link·from PC to RF transmitter then to the·Boe bot kit built with RF receiver. So that i'm able build·a communicate link·from PC to the Boe Bot robot kit in wireless mode.

For the RF transmitter, there are no BS2 built however the RF receiver is built on the Boe Bot robot kit with BS2.

The RF transmitter is actually built on the module that consists of MAX232 chip, Inverter chip and a RS232 port that used it·to connect to the PC. I got this ideal from the data for exchange file from parallax website.

Therefore I'm trying to use visual basic software to create a communicate between PC to Boe Bot robot kit so that i can able instruct·the Boe Bot robot to move upon the action icon clicked provided on the Visual Basic GUI.

Do i really need to buy another BS2 in order to create a communication link from PC to Boe Bot robot kit in wireless?

If not, please advise how to i create a link?

Please advise, i really need your guy for advise and guidence as i very new in this area.

Regards,

New1976

Jon Williams

No, you should not need another BS2.

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Jon Williams
Applications Engineer, Parallax

Tom Walker

The short answer is that you do not need another Stamp on the "PC" or "transmitting" end. You should be able to communicate through the serial port (using VB) to your '232/transmitter module to your receiver on the BOE-Bot to the Stamp thereon. Take it a step at a time and it will come together. Be aware, however, that you will not be able to PROGRAM the Stamp using this link...only send it commands that a program on the Stamp can interpret.

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Truly Understand the Fundamentals and the Path will be so much easier...

New1976

Hi Tom and Jon,

Thanks for your prompt respond. At least i know my hardware can work, the problem lies on the program.

Aside to Tom Walker,

You saying, i need to send the commands·that a·program on the Stamp can interpret. So you mean that, the command is the variable i have define and downloaded·before hard on the BS2 at my Boe bot robot? In other words, ·i have to downloaded the required program into the BS2 and define the variable accordingly. example :

Example Variable define:

Variable "1" for command the robot to move forward

Variable·"2" for command the robot to move backward

Variable·"3" for command the robot to move left

Variable·"4" for command the robot to move right

Am i right to say that? please direct me if i'm wrong.

Can i still used the Serin/ serout type of program or i just create the BS2 source code under the subroutine in the basic stamp editor and define the variable accordingly?

What is the·proper way to create the source code in the Basic stamp editor·and define the variable

accordingly? please advise,

Is there any material whiich i can learn the topic regarding the·link, program and the command?

Please advise. You help and guidence is really a great help to me.

Regards,

New1976

New1976

Hi Tom Walker,·Jon Williams (Parallax) and Paul Baker,

I managed to downloaded the BS2 from PC to·BOE BOT robot kit in wireless appliation.

I want take this time thanks you for your help·provided.

Really appreciate your help.

Regards,

New1976·