include corrected, basic example added

Author: mestrode

README.md

@@ -1,10 +1,20 @@
 # LIN-Transceiver-Library (TJA1020)
 
-Extends the Lin-Interface class and ensure the TJA1020 statemachine will be served in the correct way
+Using a LIN Bus via TJA1020 Transceiver needs to handle the statemachine bevor you will be able to send or receive data from the bus. This is encapsulated within this class.
 
-example:
+# dependencies
 
-    #include "TJA1020.h"
+This library extends the Lin-Interface Library:
+https://github.com/mestrode/Lin-Interface-Library
+
+# example
+Take a look into the basic example.
+
+Library should work like the Lin-Interface Library, but considers the statemachine in every readFrame and writeFrame method.
+You can also control the statemachine, eg. the default slope mode.
+
+```cpp
+    #include "TJA1020.hpp"
 
     #define LIN_SERIAL_SPEED 19200
     #define lin_NSLP_Pin 32
@@ -14,20 +24,28 @@ example:
 
     void setup()
     {
-
+        // use LowSlope mode all the time
+        LinBus.Slope(LinBus.LowSlope);
     }
 
-    void loop()
+    uint8_t getData()
     {
         uint8_t data = 0x00;
 
-        // Read Frame FID = 0x20
+        // Read Frame ID = 0x20
         if (LinBus.readFrame(0x20))
         {
             // Read succesfull
-            data = LinBus.LinMessage[0];
+            data = LinBus.LinMessage[0]; // only consider byte 0 of the received data
         }
 
-        // let LIN-Tranceiver sleep
+        // let LIN-Tranceiver sleep --> changes also the INH Pin of the TJA1020
         LinBus.setMode(LinBus.Sleep);
+
+        return data;
     }
+```
+
+# see also
+
+* Datasheet of TJA1020 https://www.nxp.com/docs/en/data-sheet/TJA1020.pdf

example/basic/platformio.ini

@@ -0,0 +1,17 @@
+; PlatformIO Project Configuration File
+;
+;   Build options: build flags, source filter
+;   Upload options: custom upload port, speed and extra flags
+;   Library options: dependencies, extra library storages
+;   Advanced options: extra scripting
+;
+; Please visit documentation for the other options and examples
+; https://docs.platformio.org/page/projectconf.html
+
+[env:esp32doit-devkit-v1]
+platform = espressif32
+board = esp32doit-devkit-v1
+framework = arduino
+lib_deps =
+    https://github.com/mestrode/Lin-Interface-Library.git
+    https://github.com/mestrode/Lin-Transceiver-Library.git

example/basic/src/main.cpp

@@ -0,0 +1,67 @@
+#include <Arduino.h>
+#include <TJA1020.hpp>
+
+#define PIN_NSLP 23
+
+// using a TJA1020 chip
+// using UART 1 for LinBus
+// configure 19200 Baud
+// using GPIO 23 for /NSLP pin of TJA1020
+Lin_TJA1020 LinBus(1, 19200, PIN_NSLP);
+
+// data to be filled by bus request
+float Cap_Max = 0.0;
+float Cap_Available = 0.0;
+uint8_t Cap_Configured = 0;
+uint8_t CalibByte = 0x00;
+bool CalibrationDone = false;
+
+void setup()
+{
+  // Serial represents Serial(0)
+  Serial.begin(115200);
+
+  // configure slope rate
+  Serial.print("configure low slope rate of TJA1020\n");
+  LinBus.setSlope(LinBus.LowSlope);
+}
+
+bool readLinData()
+{
+  // all handling of
+  bool chkSumValid = LinBus.readFrame(0x2C);
+  if (chkSumValid)
+  {
+    // Data now avaliabele in LinBus.LinMessage
+
+    // decode some bytes (incl. rescaling)
+    Cap_Max = (float((LinBus.LinMessage[1] << 8) + LinBus.LinMessage[0])) / 10;
+    Cap_Available = (float((LinBus.LinMessage[3] << 8) + LinBus.LinMessage[2])) / 10;
+
+    // receive a single byte
+    Cap_Configured = LinBus.LinMessage[4];
+
+    // decode flags within a byte
+    CalibByte = LinBus.LinMessage[5];
+    CalibrationDone = bitRead(LinBus.LinMessage[5], 0);
+  }
+  return chkSumValid;
+}
+
+void loop()
+{
+  if (readLinData())
+  {
+    Serial.print("Data reveived:\n");
+    Serial.printf("  Cap_Max = %f\n", Cap_Max);
+    Serial.printf("  Cap_Available = %f\n", Cap_Available);
+    Serial.printf("  Cap_Configured = %d\n", Cap_Configured);
+    Serial.printf("  CalibByte = %02Xh\n", CalibByte);
+    Serial.printf("  CalibrationDone = %d\n", CalibrationDone);
+  }
+
+  delay(5000);
+
+  //shut TJA1020 down, this also releases the INH pin.
+  LinBus.setSlope(LinBus.Sleep);
+}

src/TJA1020.cpp

@@ -10,7 +10,7 @@
 
 #include "TJA1020.hpp"
 
-#include <Lin-Interface.h>
+#include <Lin-Interface.hpp>
 // #include <Arduino.h>
 
 //-----------------------------------------------------------------------------