Release code

F1:F103/FX3U/Readme.md

@@ -0,0 +1,75 @@
+A usefull thing made of chineese FX3U clone
+===========================================
+
+Works over RS-232 (default: 115200, 8N1) or CAN (default 250000 baud).
+
+You can see pinout table in file `hardware.c`.
+
+## Serial protocol (each string ends with '\n').
+
+```
+commands format: parameter[number][=setter]
+parameter [CAN idx] - help
+--------------------------
+
+    CAN bus commands:
+canbuserr - print all CAN bus errors (a lot of if not connected)
+cansniff - switch CAN sniffer mode
+
+    Configuration:
+bounce [14] - set/get anti-bounce timeout (ms, max: 1000)
+canid [6] - set both (in/out) CAN ID / get in CAN ID
+canidin [7] - get/set input CAN ID
+canidout [8] - get/set output CAN ID
+canspeed [5] - get/set CAN speed (bps)
+dumpconf - dump current configuration
+eraseflash [10] - erase all flash storage
+saveconf [9] - save configuration
+usartspeed [15] - get/set USART1 speed
+
+    IN/OUT:
+adc [4] - get raw ADC values for given channel
+esw [12] - anti-bounce read inputs
+eswnow [13] - read current inputs' state
+led [16] - work with onboard LED
+relay [11] - get/set relay state (0 - off, 1 - on)
+
+    Other commands:
+mcutemp [3] - get MCU temperature (*10degrC)
+reset [1] - reset MCU
+s - send CAN message: ID 0..8 data bytes
+time [2] - get/set time (1ms, 32bit)
+wdtest - test watchdog
+error=badcmd
+```
+
+Value in square brackets is CAN bus command code.
+
+## CAN bus protocol
+
+All data in little-endian format!
+
+BIT -  MEANING
+
+0, 1 - (uint16_t) - command code (value in square brackets upper);
+
+2 - (uint8_t) - parameter number (e.g. ADC channel or X/Y channel number), 0..127 [ORed with 0x80 for setter];
+
+3 - (uint8_t) - error code (only when device answers for requests);
+
+4..7 - (int32_t) - data.
+
+### CAN bus error codes
+
+0 - `ERR_OK`       - all OK,
+
+1 - `ERR_BADPAR`   - parameter is wrong,
+
+2 - `ERR_BADVAL`   - value is wrong (e.g. out of range),
+
+3 - `ERR_WRONGLEN` - wrong message length (for setter or for obligatory parameter number),
+
+4 - `ERR_BADCMD`   - unknown command code,
+
+5 - `ERR_CANTRUN`  - can't run given command due to bad parameters or other reason.
+