Update README and add support for autoretransmit enable/disable

README.md

@@ -1,8 +1,32 @@
-# CANtact Firmware
+# CANable/CANtact Firmware
 
-[![Build Status](https://travis-ci.org/linklayer/cantact-fw.svg?branch=master)](https://travis-ci.org/linklayer/cantact-fw)
+This repository contains sources for the slcan CANtact firmware modified for the CANable USB to CAN adapter.
 
-This repository contains sources for CANtact firmware.
+## Supported Commands
+
+- `O` - Open channel 
+- `C` - Close channel 
+- `S0` - Set bitrate to 10k
+- `S1` - Set bitrate to 20k
+- `S2` - Set bitrate to 50k
+- `S3` - Set bitrate to 100k
+- `S4` - Set bitrate to 125k
+- `S5` - Set bitrate to 250k
+- `S6` - Set bitrate to 500k
+- `S7` - Set bitrate to 750k
+- `S8` - Set bitrate to 1M
+- `M0` - Set mode to normal mode (default)
+- `M1` - Set mode to silent mode
+- `A0` - Disable automatic retransmission 
+- `A1` - Enable automatic retransmission (default)
+- `TIIIIIIIILDD...` - Transmit data frame (Extended ID) [ID, length, data]
+- `tIIILDD...` - Transmit data frame (Standard ID) [ID, length, data]
+- `RIIIIIIIIL` - Transmit remote frame (Extended ID) [ID, length]
+- `rIIIL` - Transmit remote frame (Standard ID) [ID, length]
+
+Note: Channel configuration commands must be sent before opening the channel. The channel must be opened before transmitting frames.
+
+This firmware currently does not provide any ACK/NACK feedback for serial commands.
 
 ## Building
 

inc/can.h

@@ -23,6 +23,7 @@ void can_enable(void);
 void can_disable(void);
 void can_set_bitrate(enum can_bitrate bitrate);
 void can_set_silent(uint8_t silent);
+void can_set_autoretransmit(uint8_t autoretransmit);
 uint32_t can_tx(CanTxMsgTypeDef *tx_msg);
 uint32_t can_rx(CanRxMsgTypeDef *rx_msg, uint32_t timeout);
 

src/can.c

@@ -166,6 +166,23 @@ void can_set_silent(uint8_t silent)
 }
 
 
+// Set CAN peripheral to silent mode
+void can_set_autoretransmit(uint8_t autoretransmit)
+{
+    if (bus_state == ON_BUS)
+    {
+        // cannot set silent mode while on bus
+        return;
+    }
+    if (autoretransmit)
+    {
+    	can_handle.Init.NART = DISABLE;
+    } else {
+    	can_handle.Init.NART = ENABLE;
+    }
+}
+
+
 // Send a message on the CAN bus (blocking)
 uint32_t can_tx(CanTxMsgTypeDef *tx_msg)
 {

src/slcan.c

@@ -154,6 +154,18 @@ int8_t slcan_parse_str(uint8_t *buf, uint8_t len)
         }
         return 0;
 
+    } else if (buf[0] == 'a' || buf[0] == 'A') {
+        // set autoretry command
+        if (buf[1] == 1) 
+        {
+            // mode 1: autoretry enabled (default)
+            can_set_autoretransmit(1);
+        } else {
+            // mode 0: autoretry disabled
+            can_set_autoretransmit(0);
+        }
+        return 0;
+
     } else if (buf[0] == 't' || buf[0] == 'T') {
         // transmit data frame command
         frame.RTR = CAN_RTR_DATA;