Discussion in "Project Help" started by    mhmd_saud    Nov 11, 2009.
Fri Mar 19 2010, 01:31 am
well check if there is a PWRKEY kind of switch or a push button is there.

you might need to press it for 1 or 2 sec till you see LED blinking fast.

can you post details on this EVB. it would be easy to help if i can see schematic or a block diagram kind of thing.
Fri Mar 19 2010, 07:15 am

The power supple came with the kit. That adapter thing. But if it came with the kit, then it should be supplying the right amount of input right?


It certainly should, but it may not be.
It is something you can check easily with a meter.

I'm wondering what else could be the problem, is it possible that I might have to change any of the components on the board or something.


If there is a fault on the board you really should return it to Farnell.

If I found a fault and was 100% sure I could fix it I would risk it,
but I don't think you should.
Farnell would refuse to replace/or refund if you work on the board.

Could the staff at your school/college help.

Farnell , the company I bought it from, isn't much help. I tried contacting them asking if they could test it for me, and they said they don't do that.
I've paid too much to NOT do anything about it.


Farnell will have to do something if you can be sure the board is faulty,the problem is to know
where the fault is.
It could be the SIM300

If I were you I would..
1: Check the voltage into the board.
2: Check the SIM300 if fully seated in the 60way connected(press down well)
3 Fit all accessories, antenna, sim card etc, try another known good sim card.

Try all combination's of switches
make sure to hold the Power switch for well over a second.
Please tell us the voltages on all 5 pins of IC D201, be careful not to short any pins together
while measuring.

For those interested, this is a link to the board's manual.


can you post details on this EVB.
it would be easy to help if i can see schematic or a block diagram kind of thing.

Ajay Bhargav

Sat Mar 20 2010, 11:00 pm
Omg, I finally got it to run.
Turns out, the SIM300 wasn't fully seated onto the board properly & I didn't eve realize it!! Thank God it's working & I don't have to contact Farnell about it!

I even managed to try sending out smses from it already.
So now, onto getting the right codes for the process.
Thanks guys for the advice about getting the board to run
Sun Mar 21 2010, 01:54 am
That's great news
Mon Mar 22 2010, 03:14 pm
yeah.. glad to hear its working.. hope to see some of your work on board now..
good luck!
Tue Mar 23 2010, 07:03 am
So basically right now, my friend has already programmed the PIC connected to her GPS for it to be able to display its data on the lcd screen.

I'll be using another PIC for my SIM300 evb to connect to her GPS.
I've already managed to send out smses with the SIM evb, so how do I get the SIM evb to receive data from the GPS automatically?
Tue Mar 23 2010, 06:21 pm
i dont get it..
you are using 2 PIC controllers? you should be using 1 PIC and it should be connected to both GPS and GSM. so once you get data from GPS parse it and send to to GSM modem. everything on single board.
Wed Mar 24 2010, 08:18 am
Because the PIC we're using only has 1 UART (16F877A, I think).
You said we have to have two UARTs, right?

Right now, if my friend has already used one PIC to program the display on the lcd screen, can that same PIC be used to connect her GPS to mine? I dont think so, right?
Wed Mar 24 2010, 05:48 pm
you could multiplex UARTs bus that will make your job a little tedious.
now that you already have 2 PIC controllers ready, with devices connected. you can now use some other means of communication between your controllers like SPI or a software UART.

you can get software uart code from microchip website. so the GSM controller will send command to GPS controller on software uart/SPI and GPS controller will reply back with GPS data.
Thu Mar 25 2010, 02:14 am
Using two PICs would be a poor design simply because it is wasteful,
also communicating between them is just as complicated as connecting
the GPS and modem to one PIC.

There are ways to connect two serial devices to one PIC.

There may be simpler way in this case.
I think the PIC only needs the receive data from the GPS and only needs to
send data to the modem.
You could use the PIC's one serial port for both.

The PIC doesn't need to see the responses from the modem once everything
is tested and working.
During testing you could use a switch to select input from the GPS or modem.

Get Social


Powered by e107 Forum System



Fri Sep 22 2023, 05:09 pm
Fri Sep 22 2023, 04:17 pm
Fri Sep 22 2023, 03:39 pm
Fri Sep 22 2023, 02:05 pm
Thu Sep 21 2023, 03:03 pm
Thu Sep 21 2023, 08:19 am
Wed Sep 20 2023, 08:40 am
Wed Sep 20 2023, 05:47 am