readme.rst: Clarifications

diff --git a/readme.rst b/readme.rst
index a35c26094f059a89c9dec92a78497f4eebcfd40f..9924167e59f7073867be5f9a031775ccc7a92eab 100644 (file)
--- a/readme.rst
+++ b/readme.rst
@@ -11,12 +11,13 @@ Max Staudt <max-linux@enpas.org>
 Motivation
 -----------
 
 Motivation
 -----------
 

-CAN adapters are expensive, few, and far between.
-ELM327 interfaces are cheap and plentiful.
-

 This driver aims to lower the initial cost for hackers interested in
 working with CAN buses.
 
 This driver aims to lower the initial cost for hackers interested in
 working with CAN buses.
 

+CAN adapters are expensive, few, and far between.
+ELM327 interfaces are cheap and plentiful.
+Let's use ELM327s as CAN adapters.
+

 
 
 Introduction
 
 
 Introduction


@@ -27,7 +28,7 @@ into full-fledged (as far as possible) CAN interfaces.
 
 Since the ELM327 was never meant to be a stand-alone CAN controller,
 the driver has to switch between its modes as quickly as possible in
 
 Since the ELM327 was never meant to be a stand-alone CAN controller,
 the driver has to switch between its modes as quickly as possible in

-order to approximate full-duplex operation.
+order to fake full-duplex operation.

 
 As such, elmcan is a best-effort driver. However, this is more than
 enough to implement simple request-response protocols (such as OBD II),
 
 As such, elmcan is a best-effort driver. However, this is more than
 enough to implement simple request-response protocols (such as OBD II),


@@ -67,6 +68,7 @@ How to check the controller version
 ------------------------------------
 
 Use a terminal program to attach to the controller.
 ------------------------------------
 
 Use a terminal program to attach to the controller.

+The default settings are 38400 baud/s, 8 data bits, no parity, 1 stopbit.

 
 After issuing the "``AT WS``" command, the controller will respond with
 its version::
 
 After issuing the "``AT WS``" command, the controller will respond with
 its version::


@@ -78,6 +80,9 @@ its version::
 
     >
 
 
     >
 

+Note that clones may claim to be any version they like.
+It is not indicative of their actual feature set.
+

 
 
 How to attach the line discipline
 
 
 How to attach the line discipline


@@ -111,6 +116,8 @@ Module parameters
        Some adapters and/or their connection are unreliable. Enable this
        option to try and work around the situation. This is a best-effort
        workaround, so undefined behavior will likely occur sooner or later.
        Some adapters and/or their connection are unreliable. Enable this
        option to try and work around the situation. This is a best-effort
        workaround, so undefined behavior will likely occur sooner or later.

+       Without this option, the driver will bail on the first unrecognized
+       character it receives from the TTY.

 
        LOAD TIME::
 
 
        LOAD TIME::
 


@@ -121,7 +128,7 @@ Module parameters
 Known limitations of the controller
 ------------------------------------
 
 Known limitations of the controller
 ------------------------------------
 

-- Clone "v1.5" devices
+- Clone devices ("v1.5" and others)

 
   Sending RTR frames is not supported and will be dropped silently.
 
 
   Sending RTR frames is not supported and will be dropped silently.
 


@@ -139,8 +146,8 @@ Known limitations of the controller
 
 - All versions
 
 
 - All versions
 

-  No automatic full duplex operation is supported. The driver will
-  switch between input/output mode as quickly as possible.
+  No full duplex operation is supported. The driver will switch
+  between input/output mode as quickly as possible.

 
   The length of outgoing RTR frames cannot be set. In fact, some
   clones (tested with one identifying as "``v1.5``") are unable to
 
   The length of outgoing RTR frames cannot be set. In fact, some
   clones (tested with one identifying as "``v1.5``") are unable to