Am 02.02.2012 22:58, schrieb Roberto Spadim:
> well must check source code and see if it´s a time problem on
> communications, im a bit busy here, with time i can check, if anyone can
> check what changed in this versions that worked and that don´t work
> could be nice
> i will be out for 1 month +- with a big work
I'll try to find as much as possible, because to be honest I think there
more than one thing wrong using DS9490, it also isn't perfect with 2.8p2..
Short conclusion: If my assumptions are right, reading a DS18B20
(parasite OR powered doesnt matter) switches the DS2490 from flexible to
regular-speed and disables Strong pullup..
-> As a first step I added some more debugging, to see whats going on;
patch attached
It's all inside OW_SHOW_TRAFFIC enabled with configure ...
--enable-owtraffic so it shouldnt hurt..
Though I'm not sure it's right, I used the DS2490 datasheet and while
typing it I found some discrepancies to at least existing comments in
the source..
My findings so far:
- One thing I came across reading sources and datasheets: recommended
for longer buses is a Pulldown Slew Rate of 1V/us (0x4), default and
used is 0.83V/us (0x5)
- Speed goes from initial flexible to regular (0x0) after reading a
DS18B20 sensor? And Strong Pullup is disabled then?
Started:
DEBUG: ow_usb_msg.c:(212) USB status registers EFlags:7->SPU:1
Dspeed:1,Speed:1,SPUdur:0, PDslew:5, W1lowtime:4, W0rectime:4,
DevState:32, CC1:253, CC2:72, CCState:0, DataOutState:0, DataInState:8
(same after reading a DS2438)
After first read of a DS18B20:
DEBUG: ow_usb_msg.c:(212) USB status registers EFlags:0->SPU:0
Dspeed:0,Speed:0,SPUdur:32, PDslew:5, W1lowtime:4, W0rectime:4,
DevState:32, CC1:117, CC2:8, CCState:0, DataOutState:0, DataInState:9
best regards
Michael
--- owfs-2.8p14/module/owlib/src/c/ow_usb_msg.c 2011-11-20 22:39:51.000000000 +0100
+++ module/owlib/src/c/ow_usb_msg.c 2012-02-04 14:59:14.556483753 +0100
@@ -196,6 +196,46 @@
if (buffer[8] & STATUSFLAGS_IDLE) {
#if OW_SHOW_TRAFFIC
_Debug_Bytes("USB status registers ---- idle ----", buffer, ret) ; // debugging
+ //FIXME: if the line below really works we dont nee the line above ;)
+ LEVEL_DEBUG("USB status registers EFlags:%u->SPU:%u Dspeed:%u,Speed:%u,SPUdur:%u, PDslew:%u, W1lowtime:%u, W0rectime:%u, DevState:%u, CC1:%u, CC2:%u, CCState:%u, DataOutState:%u, DataInState:%u",
+ buffer[0], (buffer[0]&0x01), (buffer[0]&0x04 ? 1 : 0),
+ buffer[1],
+ buffer[2],
+ buffer[4],
+ buffer[5],
+ buffer[6],
+ buffer[8],
+ buffer[9],
+ buffer[10],
+ buffer[11],
+ buffer[12],
+ buffer[13] );
+ /*
+ Datasheet DS2490 page 29 table 16
+ 0: Enable Flags: SPUE=1(bit0) If set to 1, the strong pullup to 5V is enabled, if set to 0, it is disabled.
+ bit1 should be 0 but is 1 ?! SPCE = 4(bit2) If set to 1, a dynamic 1-Wire bus speed change through a Communication command is enabled, if set to 0, it is disabled.
+ 1: 1-Wire Speed
+ 2: Strong Pullup Duration
+ 3: (Reserved)
+ 4: Pulldown Slew Rate
+ 5: Write-1 Low Time
+ 6: Data Sample Offset / Write-0 Recovery Time
+ 7: reserved
+ 8: Device Status Flags: bit0: SPUA if set to 1, the strong pullup to 5V is currently active, if set to 0, it is inactive.
+ bit3(8): PMOD if set to 1, the DS2490 is powered from USB and external sources, if set to 0, all DS2490 power is provided from USB. FIXME: expose this to clients to check!
+ bit4(16): HALT if set to 1, the DS2490 is currently halted, if set to 0, the device is not halted.
+ bit5(32): IDLE if set to 1, the DS2490 is currently idle, if set to 0, the device is not idle.
+ bit5(64): EPOF: Endpoint 0 FIFO status, see: If EP0F is set to 1, the Endpoint 0 FIFO was full when a new control transfer setup packet was
+ received. This is an error condition in that the setup packet received is discarded due to the full
+ condition. To recover from this state the USB host must send a CTL_RESET_DEVICE command; the
+ device will also recover with a power on reset cycle. Note that the DS2490 will accept and process a
+ CTL_RESET_DEVICE command if the EP0F = 1 state occurs. If EP0F = 0, no FIFO error condition exists.
+ 9: Communication Command, Byte 1
+ 10: Communication Command, Byte 2
+ 11: Communication Command Buffer Status
+ 12: 1-Wire Data Out Buffer Status
+ 13: 1-Wire Data In Buffer Status
+ */
#endif /* OW_SHOW_TRAFFIC */
if (*readlen > 0) {
// we have enough bytes to read now!
@@ -210,6 +250,20 @@
} else {
#if OW_SHOW_TRAFFIC
_Debug_Bytes("USB status registers ---- Not idle -----", buffer, ret) ; // debugging
+ //FIXME: if the line below really works we dont nee the line above ;)
+ LEVEL_DEBUG("USB status registers EFlags:%u->SPU:%u Dspeed:%u,Speed:%u,SPUdur:%u, PDslew:%u, W1lowtime:%u, W0rectime:%u, DevState:%u, CC1:%u, CC2:%u, CCState:%u, DataOutState:%u, DataInState:%u",
+ buffer[0], (buffer[0]&0x01), (buffer[0]&0x04 ? 1 : 0),
+ buffer[1],
+ buffer[2],
+ buffer[4],
+ buffer[5],
+ buffer[6],
+ buffer[8],
+ buffer[9],
+ buffer[10],
+ buffer[11],
+ buffer[12],
+ buffer[13] );
#endif /* OW_SHOW_TRAFFIC */
}
// this value might be decreased later...
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