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hw:usb_watchdog [2020/10/04 12:52] – niziakhw:usb_watchdog [2020/10/14 20:41] (current) – niziak
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 Serial port parameters: 9600 8N1 Serial port parameters: 9600 8N1
 +<code bash>stty -F /dev/ttyUSB0 raw speed 9600</code>
  
 +Each command is 1 byte value. It set watchdog threshold in deciseconds. Example commands:
 Commands sent to watchdog (1 byte): Commands sent to watchdog (1 byte):
-  * ''1'' - next expected kick in 10 seconds  +  * ''1'' - next expected kick in 10 seconds. <code bash> echo -ne "\x01" > /dev/ttyUSB0</code> 
-  * ''36'' - next expected kick in 360 seconds  +  * ''36'' - next expected kick in 360 seconds. <code bash> echo -ne "\x01" > /dev/ttyUSB0</code>  
-  * ''255'' - reset now +  * ''128'' - status query. It responds with ''0x81'' <code bash> echo -ne "\x80" > /dev/ttyUSB0</code>  
-  * +  * ''255'' - forced reset. <code bash> echo -ne "\xFF" > /dev/ttyUSB0</code> 
 + 
 +REMARK: Avoid low threshold. It is stored internally in watchdog, so after reset it is still low. In this case it is not possible to boot OS. 
 + 
 +Default (after powerup) watchdog window is 170 sec (measured).
  
 ===== Daemon ===== ===== Daemon =====