Serial data

[kam]

Hi all,

Im sort of new to Picaxe. I was trying to send some serial data from my 28X to the coms port. What I was trying to achieve was to send a string to ask for a number. That number would then be used as a counter limit to flash an LED. I couldnt get it running but i also noticed that on my coms to USB dongle the Rx LED stays constantly ON. May be its not letting any data back in. I am using a MAX 232 converter in the middle. Also the CTS and RTS have been grounded and Im using an 8MHz Clock. I have already seen all the other links related to the Serial Coms, but i dont see the problem. I sure im missing out on a small bit... Its always the case. Heres the code:

;Connections:
;Pin Out1 to SerTx
;Pin Out2 to LED
;Pin Out3 to SerRX
;-----------------------

main:

let b1 = 0
let b2 = 0
serout 1, N4800,("Please Enter The Number Of Times You Want The LED To Flash: ")
pause 250

datain:
serin 3,n4800, b2
wait 2

datacheck:
if b2 > b1 then goto flash
goto datacheck

flash:

for b3=0 to b2
high 2
wait 2 ; with 8 MHz clock the cycle is half the requested time, Hence 1 Sec.
low 2
wait 2
serout 1,N4800,("LED Flashing from 1 to : ",#b3,lf)
next b3

serout 1,N4800,("LED Flash Complete ",lf)
pause 500
goto main


Hope this helps
Thanx

 

[picaxester]

Maybe try T4800, I think the MAX 232 might invert it

 

[kam]

i should have mentioned, I tried that too. No difference. I can read the message being sent to the Terminal but cant get any massage through to the micro.
thanx

 

[hippy]

You may have to disable handshaking for whatever comms program you are running onthe PC. You'll want "No Handshaking" rather than "Hardware handshaking CTS/RTS" or "Software (X-ON/X-OFF) Handshaking".

Also, when typing a number for the PICAXE remember to press return after it

 

[moxhamj]

What program are you using on the PC? I am a bit confused by the problem still - is it PC to micro or micro to PC? Have you read http://www.instructables.com/id/Control-real-world-devices-with-your-PC/

I'm sure we can troubleshoot it but the problem needs to be isolated more. At the very simplest level leave out the picaxe and run a VB.Net program or hyperterminal program to send out one byte and read that byte back and simply connect pin 2 and 3 together. This at least will test the USB dongle works. RTS and CTS shouldn't be connected to anything.

Does the USB device work for programming a picaxe? If so then lots of things are already working.

 

[kam]

What program are you using on the PC? I am a bit confused by the problem still - is it PC to micro or micro to PC? Have you read http://www.instructables.com/id/Control-real-world-devices-with-your-PC/

I'm sure we can troubleshoot it but the problem needs to be isolated more. At the very simplest level leave out the picaxe and run a VB.Net program or hyperterminal program to send out one byte and read that byte back and simply connect pin 2 and 3 together. This at least will test the USB dongle works. RTS and CTS shouldn't be connected to anything.

Does the USB device work for programming a picaxe? If so then lots of things are already working.

Hi,
Yes the USB device works well for programming the Picaxe. i also used it to transmit data to COMS sucessfully. I use the Pixace Programing Editor Terminal. So i think, for standard issue it should respond.
i'll try your suggestions one by one and will update the result

 

[andrew_qld]

I had some serial probelms with a 28X1 recently. Two things to check, first make sure the power supply is well filtered (100uF electro) and if it still won't work, try using a diferent resonator.

The 28X1 I had would do fine using ts internal resonator at 2400 baud but not 9600. I put a 16 MHz resonator in and it all worked.