Frecuency Hoping using SMIRF v2

Wireless & IoT
1

I want to know what is the minium delay time between commands to configure the smirf v2 in the quick configuration mode. when I open the terminal and I press ctrl+t 5 times and then select the proper configuration. the smirf v2 accept this configuration but when I send all the string, the smirf base doesn’t accept the configuration.

Thanks

2

Good question.

The channel switching is nearly instantaneous. The bottleneck is the PIC recording the new selection into EEPROM memory. Allow ~1-200ms before sending any data down the link.

Break down exactly what you are sending the SMiRF and I will see if there is any problem with the string.

-Nathan

3

Hi Nathan

I send the following string:

20 20 20 20 20 49 14 120

To change the channel to 14 and just exit of the quick configuration mode.

is it correct? I’m using a visual basic test program.

Do you have a visual basic program to test if it works??

Thanks

4

Shoot. That looks correct…

Take a look at the C code on SMiRF v2.1. This code is called after 5 sequential ctl+t characters are received:

    while(1)
    {
        //RX_Xmitted = RX_In; //Clear the incoming buffer

        //Wait for the user to transmit the command
        while(RX_Xmitted == RX_In); 
        command = RX_Array[RX_In];
        RX_Xmitted++;
        if(RX_Xmitted == FIFO_SIZE) RX_Xmitted = 0;

        if (command == 'x')
            break; //Return to main routine
        else
        {
            //Wait for the user to transmit the new setting
            while(RX_Xmitted == RX_In); 
            new_setting = RX_Array[RX_In];
            RX_Xmitted++;
            if(RX_Xmitted == FIFO_SIZE) RX_Xmitted = 0;

            if (command == '1') channel_number = new_setting; //Channel Switch
            if (command == '2') address_number = new_setting; //Address switch
            if (command == '3') power_level = new_setting; //Power level configuration
            if (command == '4') //Record to eeprom
            {
                onboard_eewrite(channel_number, RF_CHANNEL_SPOT);
                onboard_eewrite(address_number, RF_ADDRESS_SPOT);
                onboard_eewrite(power_level, RF_POWERLEVEL_SPOT);
            }
            
            //These values are NOT automatically recorded to EEPROM to save the 15ms of recording time
        }
    }

I really don’t know. I too use VB for a lot of testing. I’ll see if I can get to testing it today.

Try inserting a small delay (50-100ms) between the 5 ctl characters and the channel selection characters.

-Nathan

5

Are u planning to change the frequency often?

I mean changing the EEPROM every 0.5s will eventually cause the eeprom byte to fuzzle and the smirf to stop working…

6

hi Pittuck and Nathan

I need please you send me a Vb code to test because I think my program is not correct. I want to change the channel many times without saving in the eeprom. is it can be done??? or not??-

Thanks for your help

7

well up to nathan that one, i do not know smirf

What version of VB do u use? i use .net standard and vb 5 Pro (and VB embedded for pocket pc)

if u are using .net u will need to get a mscomm wrapper like net comm ocx (what i use) or if using vb 5 u can use the ms comm.

Lastly do u have any programming hardware, just in case nathan can supply a hacked version of the smirf firmware for you.

8

I have a small program in VB 6 which uses mscomm to send data over the serial port the problem is how to make a delay between the 5’s 20 and the next string to configure the channel.?? Can you send me a example of this??.

Thanks

9

use a timer

set it up for ur required time length (its set in ms) then double click it to get the ontick event. Here set a boolean flag to true and turn the timer off.

In the main code to do a delay:

timer1.start()

do while booleanflag=false

doevents(); '(application.doevents() if using .net)

loop

tbooleanflag=false

and that will do a delay for u! lol

it should do at least, code not tested, but its pretty easy to see where it is going.