Propeller Serial Communication question.

JMLStamp2p · 2007-10-26 00:25

Good evening,

I have been using a BS2 for serial communication and it is working well but I would like to use a Propeller for the speed and parallel processing. I know nothing about assembly language, do I have to use some assembly for serial communication with a propeller ?
Could someone give me a simple code sample to recieve data into a propeller using 9600 baud, 8-data bits, no-parity and 1 stop bit. I have a propeller board that I can test the program out on.

Thanks,
JMLStamp2p

Ken Peterson · 2007-10-26 01:03

JML:· The Propeller tool comes with two objects that you will probably find useful:

SimpleSerial
FullDuplexSerial

They do all the heavy lifting for you.· All you have to do is call a function to send or receive a byte on the serial connection.· SimpleSerial is a half-duplex object if your requirements are minimal.· FullDuplexSerial launches another cog and maintains a receive buffer.· It can communicate over 100 Kbaud.

You only need to know SPIN to use either.

Hope this is helpful.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔

The more I know, the more I know I don't know.· Is this what they call Wisdom?

Post Edited (Ken Peterson) : 10/26/2007 1:09:21 AM GMT

JMLStamp2p · 2007-10-26 01:28

Thanks,
Could you give me a simple code example that would set up a cog to run in a loop, look for serial data and turn on a specific led on the propeller board after I have loaded Full Duplex Serial.

JMLStamp2p

Ariba · 2007-10-26 06:18

This is a very simple example:

{{ Serial Test }}

CON
  _clkmode = xtal1 + pll16x
  _xinfreq = 5_000_000

  LED_PIN         = 16

OBJ  ser    :       "FullDuplexSerial"
  
PUB Main  | b

  ser.start(31,30,0,9600)       'start the serial driver
  dira[noparse][[/noparse]LED_PIN] := 1            'LED Pin = output

  repeat
    b := ser.rx
    outa[noparse][[/noparse]LED_PIN] := b & 1      'set LED from received Bit0

Andy

JMLStamp2p · 2007-10-26 14:35

Thank You for your help, I am studying the prop manual, a good forum makes it so much easier to learn.

JMLStamp2p

JMLStamp2p · 2007-10-26 16:27

Ariba,
I have installed your code but I get a "Circular Referance" Error when I try and load it into Ram. I am probally installing the code in the wrong place. Could you please tell me where I need to install the code, I have it installed at the top of the FullDuplexSerial
code right under the varibles declarations.

Thanks,
JMLStamp2p

Leon · 2007-10-26 16:50

You need to put it in a separate file.

Leon

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Amateur radio callsign: G1HSM
Suzuki SV1000S motorcycle

JMLStamp2p · 2007-10-26 21:27

Thanks,
I have put the code example in a seperate file and have downloaded it into the propeller with no faults. As far as downloading several files or Objects into the propeller such as FullDuplexSerial and the code sample above. Does pressing F10 download both files into the prop at once if I have both of them open in the editor? I have a Propeller Demo board with outputs 0 - 7 on the Header and would like to transmit a byte of "INVERTED DATA" out of pin 7 once every second and also blink an LED "PIN(16)" on the demo board folowing the serial transmission. Could someone adjust the following code sample to accomplish this, and what does the code fragment
| b accomplish following the MAIN statement ?
and
b := ser.tx

ser.start(31,30,1,9600)

From what I understand 30, 31 in the above statment is the recieve & transmit pins to be used, am I correct ?
If I want to use Pin "7" to transmit data out of the propeller do I need to change these accordingly or is this just the way the traces are set up on the Demo board?

thank's so much for the help.
........................................................................................................................................................................................

{{ Serial Test }}

CON
_clkmode = xtal1 + pll16x
_xinfreq = 5_000_000

LED_PIN = 16

OBJ ser : "FullDuplexSerial"

PUB Main | b

ser.start(31,30,1,9600) 'start the serial driver, Mode "1" for Inverted Data ?
dira[noparse][[/noparse]LED_PIN] := 1 'LED Pin = output

repeat
b := ser.tx
outa[noparse][[/noparse]LED_PIN] := b & 1 'set LED from received Bit0
....................................................................................................................................................................................

Leon · 2007-10-26 21:37

If you use pins 30/31 you can test the serial I/O with a Prop Plug connected to a Proto board (or something similar), using a suitable terminal program running on the PC. Modify your program to echo every character received and get that working first.

Leon

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Amateur radio callsign: G1HSM
Suzuki SV1000S motorcycle

JMLStamp2p · 2007-10-26 22:24

I have downloaded the following code and the LED's are blinking as expected, I am getting a RED blink on the USB port so I suspect that the " b:= ser.tx(01) " code is sending data out the port. I believe that I may have to adjust my scope, the propeller is so fast :>)

Does anyone know if I should change pin 30 to pin "7" since I am using a propeller demo board and have a scope attached to the header ?

.......................................................................................................................................................................................

{{ Serial Test }}

CON

_CLKMODE = RCSLOW

LED = 16

OBJ ser : "FullDuplexSerial"

PUB Main | b

dira[noparse][[/noparse]16]~~
dira[noparse][[/noparse]17]~~

ser.start(31,30,1,9600) 'start the serial driver, Mode "1" for Inverted Data ?
dira[noparse][[/noparse]LED] := 1 'Make pin 16 an Output output

repeat 3

b:= ser.tx(01)

!outa[noparse][[/noparse]16]
waitcnt(10000 + cnt)

b:= ser.tx(07)

!outa[noparse][[/noparse]16]
waitcnt(10000 + cnt)

.........................................

Leon · 2007-10-26 22:28

You need the correct clock setting for the serial routines to work, they won't work with the RC clock.

Leon

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Amateur radio callsign: G1HSM
Suzuki SV1000S motorcycle

JMLStamp2p · 2007-10-26 22:35

Thanks Leon,
Im getting somewhere, but slow :>)

JMLStamp2p

deSilva · 2007-10-26 22:38

At least not with RCSLOW...
Gosh , this is 20kHz! A SPIN line would execute in >20 ms

JMLStamp2p · 2007-10-26 23:20

Leon, Everything is working with the following code. Transmitting data out pin "7" and showing on my scope great. I have the sample time set at "100 us." I have to input waitcnt commands to slow it down enough to view it on the scope, anything slower
and it's just a "Blink" :>)
Thanks for your help,
JMLStamp2p

{{ Serial Test }}

CON

_clkmode = xtal1 + pll16x
_xinfreq = 5_000_000

LED = 16

OBJ ser : "FullDuplexSerial"

PUB Main | b

dira[noparse][[/noparse]16]~~
dira[noparse][[/noparse]7]~~

ser.start(31,7,1,9600)

waitcnt(10000000 + cnt)

repeat
!outa[noparse][[/noparse]16]
waitcnt(100000000 + cnt)
b:= ser.tx(01)
waitcnt(100000000 + cnt)
!outa[noparse][[/noparse]16]
b:= ser.tx(82)

Propeller Serial Communication question.

Comments