Hi,
I am building a system using LPC2138. I intend to have RS485 (Full duplex)
interface using UART0. I like to use ISP thru RS485. I can’t have
secondary RS232(for ISP purpose at least) interface due to board space
constrain. Could some one guide on this.
Thanks in advance,
Regards
ISP thru RS485
Started by ●February 4, 2009
Reply by ●February 4, 20092009-02-04
On Wednesday 04 February 2009 14:21, s...@gmail.com wrote:
> Hi,
>
> I am building a system using LPC2138. I intend to have RS485 (Full
> duplex) interface using UART0. I like to use ISP thru RS485. I
> can’t have secondary RS232(for ISP purpose at least) interface
> due to board space constrain. Could some one guide on this. Thanks
> in advance,
so where is the problem? Go right ahead and do it. After all RS485 is
just a physical layer and does not care what data you are carrying.
--
Rgds
JTD
> Hi,
>
> I am building a system using LPC2138. I intend to have RS485 (Full
> duplex) interface using UART0. I like to use ISP thru RS485. I
> can’t have secondary RS232(for ISP purpose at least) interface
> due to board space constrain. Could some one guide on this. Thanks
> in advance,
so where is the problem? Go right ahead and do it. After all RS485 is
just a physical layer and does not care what data you are carrying.
--
Rgds
JTD
Reply by ●February 4, 20092009-02-04
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Reply by ●February 4, 20092009-02-04
I use RS232 to RS485 converter between board and PC. The problem is the ISP
utility look for pin no 4(RS232 version) status, where is in RS485 that is being
used as Rx485+..that is where the confusion is..
>Hi,
>
>I am building a system using LPC2138. I intend to have RS485 (Full duplex) interface using UART0. I like to use ISP thru RS485. I can’t have secondary RS232(for ISP purpose at least) interface due to board space constrain. Could some one guide on this.
>Thanks in advance,
>Regards
>
>Hi,
>
>I am building a system using LPC2138. I intend to have RS485 (Full duplex) interface using UART0. I like to use ISP thru RS485. I can’t have secondary RS232(for ISP purpose at least) interface due to board space constrain. Could some one guide on this.
>Thanks in advance,
>Regards
>
Reply by ●February 4, 20092009-02-04
----Original Message----
From: l...
[mailto:l...] On Behalf Of
s...@gmail.com Sent: 04 February 2009 12:09 To:
l... Subject: [lpc2000] Re: ISP thru
RS485
> I use RS232 to RS485 converter between board and PC. The
> problem is the ISP utility look for pin no 4(RS232
> version) status, where is in RS485 that is being used as
> Rx485+..that is where the confusion is..
You can't just use an RS232 to 485 converter because RS485 is only
one-way. You will need a custom ISP utility which can change the
direction of the RS485 line.
--
Tim Mitchell
From: l...
[mailto:l...] On Behalf Of
s...@gmail.com Sent: 04 February 2009 12:09 To:
l... Subject: [lpc2000] Re: ISP thru
RS485
> I use RS232 to RS485 converter between board and PC. The
> problem is the ISP utility look for pin no 4(RS232
> version) status, where is in RS485 that is being used as
> Rx485+..that is where the confusion is..
You can't just use an RS232 to 485 converter because RS485 is only
one-way. You will need a custom ISP utility which can change the
direction of the RS485 line.
--
Tim Mitchell
Reply by ●February 4, 20092009-02-04
On Wednesday 04 February 2009 17:39, s...@gmail.com wrote:
> I use RS232 to RS485 converter between board and PC. The problem is
> the ISP utility look for pin no 4(RS232 version) status, where is
> in RS485 that is being used as Rx485+..that is where the confusion
So you got a PC with RS485 and no RS232. Neat.
--
Rgds
JTD
> I use RS232 to RS485 converter between board and PC. The problem is
> the ISP utility look for pin no 4(RS232 version) status, where is
> in RS485 that is being used as Rx485+..that is where the confusion
So you got a PC with RS485 and no RS232. Neat.
--
Rgds
JTD
Reply by ●February 4, 20092009-02-04
otherwise rs422
Tim Mitchell rašė:
> ----Original Message----
> You'd need two RS485 links to achieve full duplex.
>
Tim Mitchell rašė:
> ----Original Message----
> You'd need two RS485 links to achieve full duplex.
>
Reply by ●February 4, 20092009-02-04
"So you got a PC with RS485 and no RS232. Neat".
--
Rgds
JTD
No JTD, RS232 in the PC side and RS485 in LPC2138 board side..
--
Rgds
JTD
No JTD, RS232 in the PC side and RS485 in LPC2138 board side..
Reply by ●February 4, 20092009-02-04
JTD: I think you misunderstood. He would like to have only RS485 on
his device with LPC and use ISP.
And to the author, you will probably have to write your own custom
ISP programming application if you intend to use RS485. Or use IAP.
Re,
Uros
--- In l..., subbiah.r@... wrote:
> "So you got a PC with RS485 and no RS232. Neat".
>
> --
> Rgds
> JTD
>
> No JTD, RS232 in the PC side and RS485 in LPC2138 board side..
>
his device with LPC and use ISP.
And to the author, you will probably have to write your own custom
ISP programming application if you intend to use RS485. Or use IAP.
Re,
Uros
--- In l..., subbiah.r@... wrote:
> "So you got a PC with RS485 and no RS232. Neat".
>
> --
> Rgds
> JTD
>
> No JTD, RS232 in the PC side and RS485 in LPC2138 board side..
>
Reply by ●February 4, 20092009-02-04
For info: there are some RS232 to RS485 converters which
automatically control the RS485 direction depending on which end is
transmitting, so if your data is in command/response style message
packets (half-duplex) then you might be able to use one of those to
get started without modifying code. See Google.
Hugh
At 04:16 AM 2/4/2009, you wrote:
----Original Message----
From: l...
[mailto:l...] On Behalf Of
s...@gmail.com Sent: 04 February 2009 12:09 To:
l... Subject: [lpc2000] Re: ISP thru
RS485
> I use RS232 to RS485 converter between board and PC. The
> problem is the ISP utility look for pin no 4(RS232
> version) status, where is in RS485 that is being used as
> Rx485+..that is where the confusion is..
You can't just use an RS232 to 485 converter because RS485 is only
one-way. You will need a custom ISP utility which can change the
direction of the RS485 line.
--
Tim Mitchell
automatically control the RS485 direction depending on which end is
transmitting, so if your data is in command/response style message
packets (half-duplex) then you might be able to use one of those to
get started without modifying code. See Google.
Hugh
At 04:16 AM 2/4/2009, you wrote:
----Original Message----
From: l...
[mailto:l...] On Behalf Of
s...@gmail.com Sent: 04 February 2009 12:09 To:
l... Subject: [lpc2000] Re: ISP thru
RS485
> I use RS232 to RS485 converter between board and PC. The
> problem is the ISP utility look for pin no 4(RS232
> version) status, where is in RS485 that is being used as
> Rx485+..that is where the confusion is..
You can't just use an RS232 to 485 converter because RS485 is only
one-way. You will need a custom ISP utility which can change the
direction of the RS485 line.
--
Tim Mitchell