Update README, add known error codes and conditions1.0

1 files changed, 56 insertions, 6 deletions

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 # firmware
 Firmware for blinkenrocket
 
-Use `make && sudo make program` to flash a blinkenrocket and
-`cd utilities; ./modem_transmit string1 string2 string3 ...` to load some patterns.
+Use `make && sudo make program` to flash a blinkenrocket and use the web
+editor on <http://blinkenrocket.de/> to load patterns.
 
-## Known Bugs / TODOs
+You can also use `cd utilities; ./modem_transmit string1 string2 string3 ...`,
+though this only supports simple string patterns and a few fixed example
+animations.
 
-* Pattern transfers which are longer than ~16kbit don't work reliably and
-  may leave the device in a bogus state (requiring a power on reset before
-  new patterns can be transferred)
+# Usage
+
+## Sleep / Wakeup
+
+* Press both buttons for at least 500ms to put the rocket into deep sleep
+  (~1µW power consumption)
+* Press any key (or send a modem transmission with 100ms of extra sync pulses)
+  to turn it back on
+
+## Normal operation
+
+* Left button: Switch to previous pattern
+* Right button: Switch to next pattern
+
+The new pattern will not be loaded before the button has been released.
+
+# Error messages / conditions
+
+## "Transmission failure"
+
+A modem transmission was started, but not properly terminated. Make sure that
+your audio volume is set to 100%.
+
+## "Storage is empty"
+
+The storage does not contain any patterns yet. Use `modem_transmit` or
+<http://blinkenrocket.de/> to fill it with patterns of your choice.
+
+## Modem transmissions don't work at all
+
+Make sure that your audio volume is set to 100%. If possible, try transmitting
+from another device.
+
+## Rocket does not turn on
+
+This probably means that either your MCU (U1) is not properly powered,
+or it is unable to communicate with the storage (U2).
+
+Make sure that the right parts are soldered in the right position and check
+your soldering. Double-check parts and soldering for U1, U2, C3, R4 and R5.
+
+## Rocket hangs during patern display / when switching patterns
+
+If the display still displays something, but does not scroll/advance the
+animation anymore and the rocket does not respond to key presses, it means that
+it is unable to communicate with the EEPROM storage.
+
+Double-check parts and soldering (especially for U1, U2, C3, R4 and R5). If you
+are really sure that everything is soldered correctly, your EEPROM might be
+faulty (not as in data corruption, but as in "does not even acknowledge its
+presence anymore"). This is quite improbable, though.