[squeak-dev] Question about serial port communication

On Sat, 20 Jun 2009 16:37:53 +0200, Víctor C. T. <[hidden email]>
wrote:

> sendHello: SerialPort2
> | ba |
> ba := ByteArray new: 2.
> ba at: 1 put: 16r30.
> ba at: 1 put: 16r20.
> SerialPort2 nextPutAll: ba.

You're putting both bytes at location 1 in the ByteArray, at least in this
code, so you're sending (0x20 0x00), instead of (0x30 0x20)...

Later,
Jon

--------------------------------------------------------------
  Jon Hylands      [hidden email]      http://www.huv.com/jon

 Project: Micro Raptor (Small Biped Velociraptor Robot)
          http://www.huv.com/blog

On Sat, 20 Jun 2009 16:37:53 +0200, Víctor C. T. <[hidden email]>
wrote:

> SerialPort2 is a class that I imported from Scratch source code. The port is open correctly, I can see how the board receives data because the RX led blinks, but TX doesn't. I tried several ways to do this but anything worked. If anyone who's worked with Arduino knows what I'm doing wrong, tell me please. I will send the code and more detailed information if needed.

Can you show me how you open the SerialPort?

Later,
Jon

--------------------------------------------------------------
  Jon Hylands      [hidden email]      http://www.huv.com/jon

 Project: Micro Raptor (Small Biped Velociraptor Robot)
          http://www.huv.com/blog

On Sat, 20 Jun 2009 21:39:37 +0200, Víctor C. T. <[hidden email]>
wrote:

> Is it correct? I don't get any error at this point...

I don't see any code to specify the # of data bits, # of stop bits, or the
parity. Do they default to the "normal" values (8N1)?

Also, you need to make sure the port itself is set up without any hardware
flow control - I've never used an Arduino, but I assume its providing a USB
interface that ends up using an FT232 or something like that.

That serial port class is different than the one I use for my robotics
stuff. I've attached the serial port class I use, and it is set up like
this:

       | serialPort baudRate comPortNumber |
       baudRate := 115200.
       comPortNumber := 2.
       serialPort := SerialPort new
               baudRate: baudRate;
               dataBits: 8;
               stopBitsType: 1;
               parityType: 0;
               yourself.

       (serialPort openPort: comPortNumber) isNil
               ifTrue: [ ^self error: 'COM port not available' ].

       ...
       serialPort close.

Later,
Jon

--------------------------------------------------------------
  Jon Hylands      [hidden email]      http://www.huv.com/jon

 Project: Micro Raptor (Small Biped Velociraptor Robot)
          http://www.huv.com/blog

Certainly the class SerialPort2 that I use doesn't have any method with these initialization parameters, I didn't realize it... (this is a bit embarrassing...) :P

Well, I'll prove your code tomorrow at work. Thanks a lot for your help Jon!!!

2009/6/20 Jon Hylands <[hidden email]>

On Sat, 20 Jun 2009 21:39:37 +0200, Víctor C. T. <[hidden email]>

wrote:

> Is it correct? I don't get any error at this point...

I don't see any code to specify the # of data bits, # of stop bits, or the
parity. Do they default to the "normal" values (8N1)?

Also, you need to make sure the port itself is set up without any hardware
flow control - I've never used an Arduino, but I assume its providing a USB
interface that ends up using an FT232 or something like that.

That serial port class is different than the one I use for my robotics
stuff. I've attached the serial port class I use, and it is set up like
this:

       | serialPort baudRate comPortNumber |
       baudRate := 115200.
       comPortNumber := 2.
       serialPort := SerialPort new
               baudRate: baudRate;
               dataBits: 8;
               stopBitsType: 1;
               parityType: 0;
               yourself.

       (serialPort openPort: comPortNumber) isNil
               ifTrue: [ ^self error: 'COM port not available' ].

       ...
       serialPort close.

Later,
Jon

--------------------------------------------------------------
  Jon Hylands      [hidden email]      http://www.huv.com/jon

 Project: Micro Raptor (Small Biped Velociraptor Robot)
          http://www.huv.com/blog

--
Víctor

Sorry but this code didn't work for me, cause I'm on a Mac and it can't get port numbers, only names. Anyway initialization is not the problem: this SerialPort2 class uses two methods called getOption: and setOption:to: which get and set these port parameters (baud rate, data bits, flow control... even handshake settings). Now after starting the program I'm getting default settings on a transcript window and they seem ok:

1. baud rate: 115200
2. data bits: 8
3. stop bits: 1
4. parity type: 0
5. input flow control type: 0
6. output flow control type: 0

20. DTR: 1
21. RTS: 1
22. CTS: 0
23. DSR: 0
24. CD: 0
25. RI: 0

Then that's not the problem... I guess that the way I'm sending bytecodes it's not correct, because there's no response from board.

Thanks again :)

El 21 de junio de 2009 14:12, Víctor C. T. <[hidden email]> escribió:

Certainly the class SerialPort2 that I use doesn't have any method with these initialization parameters, I didn't realize it... (this is a bit embarrassing...) :P

Well, I'll prove your code tomorrow at work. Thanks a lot for your help Jon!!!

2009/6/20 Jon Hylands <[hidden email]>

On Sat, 20 Jun 2009 21:39:37 +0200, Víctor C. T. <[hidden email]>

wrote:

> Is it correct? I don't get any error at this point...

I don't see any code to specify the # of data bits, # of stop bits, or the
parity. Do they default to the "normal" values (8N1)?

Also, you need to make sure the port itself is set up without any hardware
flow control - I've never used an Arduino, but I assume its providing a USB
interface that ends up using an FT232 or something like that.

That serial port class is different than the one I use for my robotics
stuff. I've attached the serial port class I use, and it is set up like
this:

       | serialPort baudRate comPortNumber |
       baudRate := 115200.
       comPortNumber := 2.
       serialPort := SerialPort new
               baudRate: baudRate;
               dataBits: 8;
               stopBitsType: 1;
               parityType: 0;
               yourself.

       (serialPort openPort: comPortNumber) isNil
               ifTrue: [ ^self error: 'COM port not available' ].

       ...
       serialPort close.

Later,
Jon

--------------------------------------------------------------
  Jon Hylands      [hidden email]      http://www.huv.com/jon

 Project: Micro Raptor (Small Biped Velociraptor Robot)
          http://www.huv.com/blog

--
Víctor

--
Víctor

On Tue, 23 Jun 2009 11:06:29 +0200, Víctor C. T. <[hidden email]>
wrote:

> Sorry but this code didn't work for me, cause I'm on a Mac and it can't get port numbers, only names.

Actually, given that you're running a form of Unix, you can probably do a
soft link to the actual port in the form that Squeak is expecting. I've
done that with the gumstix (which runs Linux).

So, to make a link for ttyUSB0 so you can reference it as port 4, do this:

ln -s /dev/ttyUSB0 /dev/ttyS4

Then you can pass in 4 as the port number, and it should work.

> Then that's not the problem... I guess that the way I'm sending bytecodes it's not correct, because there's no response from board.

It may end up being an endian problem - Macs and PCs are opposite. I can't
imagine that this would manifest with a ByteArray, but its probably worth a
try just to rule it out.

Try sending a ByteArray with the bytes reversed... The other thing to try
is to send the bytes individually, with a slight (say 1 ms) delay in
between each byte.

Later,
Jon

--------------------------------------------------------------
  Jon Hylands      [hidden email]      http://www.huv.com/jon

 Project: Micro Raptor (Small Biped Velociraptor Robot)
          http://www.huv.com/blog

It may end up being an endian problem - Macs and PCs are opposite.