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diff --git a/configs/olimex-lpc1766stk/README.txt b/configs/olimex-lpc1766stk/README.txt
index f6cd75211f9..4e85a2c80c1 100644
--- a/configs/olimex-lpc1766stk/README.txt
+++ b/configs/olimex-lpc1766stk/README.txt
@@ -1072,9 +1072,9 @@ Where is one of the following:
CONFIG_LPC17XX_UART1=y
CONFIG_UART1_ISUART=y
- CONFIG_UART1_RXBUFSIZE=512
+ CONFIG_UART1_RXBUFSIZE=1024
CONFIG_UART1_TXBUFSIZE=256
- CONFIG_UART1_BAUD=9600
+ CONFIG_UART1_BAUD=2400
CONFIG_UART1_BITS=8
CONFIG_UART1_PARITY=0
CONFIG_UART1_2STOP=0
@@ -1163,10 +1163,13 @@ Where is one of the following:
Linux PC. To send a file to the PC, first make sure that the serial
port is configured to work with the board:
- $ sudo stty -F /dev/ttyS0 9600 # Select 9600 BAUD
- $ sudo stty -F /dev/ttyS0 crtscts # Enables CTS/RTS handshaking
+ $ sudo stty -F /dev/ttyS0 2400 # Select 2400 BAUD
+ $ sudo stty -F /dev/ttyS0 crtscts # Enables CTS/RTS handshaking *
$ sudo stty -F /dev/ttyS0 # Show the TTY configuration
+ * Only is hardware flow control is enabled. It is *not* in this
+ default configuration.
+
Start rz on the Linux host:
$ sudo rz /dev/ttyS0
@@ -1199,13 +1202,20 @@ Where is one of the following:
5. Receiving Files on the Target from the Linux Host PC
+ NOTE: There are issues with using the Linux sz command with the NuttX
+ rz command. See "STATUS" below. It is recommended that you use the
+ NuttX sz command on Linux as described in the next paragraph.
+
To send a file to the target, first make sure that the serial port on
the host is configured to work with the board:
- $ sudo stty -F /dev/ttyS0 9600 # Select 9600 BAUD
- $ sudo stty -F /dev/ttyS0 crtscts # Enables CTS/RTS handshaking
+ $ sudo stty -F /dev/ttyS0 2400 # Select 2400 BAUD
+ $ sudo stty -F /dev/ttyS0 crtscts # Enables CTS/RTS handshaking *
$ sudo stty -F /dev/ttyS0 # Show the TTY configuration
+ * Only is hardware flow control is enabled. It is *not* in this
+ default configuration.
+
Start rz on the on the target:
nsh> rz -d /dev/ttyS1
@@ -1234,14 +1244,17 @@ Where is one of the following:
install rzsz (or possibily lrzsz).
STATUS
- 2013-7-15: I have been able to send large and small files with the
- sz command. I have been able to receive small files, but there are
- problems receiving large files: The Linux SZ does not obey the
- buffering limits and continues to send data while rz is writing
- the previously received data to the file and the serial driver's RX
- buffer is overrun by a few bytes while the write is in progress. As
- a result, when it reads the next buffer of data, a few bytes may be
- missing. The symptom of this missing data is a CRC check failure.
+ 2013-7-15: Testing against the Linux rz/sz commands.
+
+ I have been able to send large and small files with the target sz
+ command. I have been able to receive small files, but there are
+ problems receiving large files using the Linux sz command: The
+ Linux SZ does not obey the buffering limits and continues to send
+ data while rz is writing the previously received data to the file
+ and the serial driver's RX buffer is overrun by a few bytes while
+ the write is in progress. As a result, when it reads the next
+ buffer of data, a few bytes may be missing. The symptom of this
+ missing data is a CRC check failure.
Either (1) we need a more courteous host application, or (2) we
need to greatly improve the target side buffering capability!
@@ -1249,9 +1262,25 @@ Where is one of the following:
We might get better behavior if we use the NuttX rz/sz commands
on the host side (see apps/system/zmodem/README.txt).
- 2013-7-16: I have verified that with debug off and at lower serial
- BAUD (2400), the transfers of large succeed without errors. I do
- not consider this a "solution" to the problem. I also found that
- the LPC17xx hardware flow control causes strange hangs; Zmodem
- works better with hardware flow control disabled.
+ 2013-7-16: More Testing against the Linux rz/sz commands.
+ I have verified that with debug off and at lower serial
+ BAUD (2400), the transfers of large files succeed without errors. I
+ do not consider this a "solution" to the problem. I also found that
+ the LPC17xx hardware flow control causes strange hangs; Zmodem works
+ much better with hardware flow control disabled.
+
+ At this lower BAUD, RX buffer sizes could probably be reduced; Or
+ perhaps the BAUD coud be increased. My thought, however, is that
+ tuning in such an unhealthy situation is not the approach: The
+ best thing to do would be to use the matching NuttX sz on the Linux
+ host side.
+
+ 2013-7-16. More Testing against the NuttX rz/sz on Both Ends.
+
+ The NuttX sz/rz commands have been modified so that they can be
+ built and executed under Linux. In this case, there are no
+ transfer problems at all in either direction and with large or
+ small files. This configuration could probably run at much higher
+ serial speeds and with much smaller buffers (although that has not
+ been verified as of this writing).
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