Add support for encoder knob on MD-UV380

Added: qdec, a header only quadrature encoder library

Added: EXTI15_10_IRQHandler to handle the encoder knob

Changed: platform_init() for the MD-UV380 now configures the EXTI15_10
interrupt.

Changed: platform_getChSelector now returns signed int8

Changed: size of settings_t.valid went from 6 to 7
Without this change, pressing the macro button crashes the radio, I
haven't investigated and I don't remember how I found that solution.

Changed: meson.build includes the qdec library

lib/qdec/include/qdec.h

@@ -0,0 +1,60 @@
+enum QDECODER_EVENT {
+    QDECODER_EVENT_NONE   = 0x00u,
+    QDECODER_EVENT_CW     = 0x80u,
+    QDECODER_EVENT_CCW    = 0x40u,
+};
+
+// state is internal... needs never be exposed to callers
+enum QDECODER_STATE {
+    QDECODER_STATE_START      = 0x00u,
+    QDECODER_STATE_CW_A       = 0x01u,
+    QDECODER_STATE_CW_B       = 0x02u,
+    QDECODER_STATE_CW_C       = 0x03u,
+    QDECODER_STATE_MID        = 0x04u,
+    QDECODER_STATE_CCW_A      = 0x05u,
+    QDECODER_STATE_CCW_B      = 0x06u, 
+    QDECODER_STATE_CCW_C      = 0x07u,
+};
+
+const uint8_t QDECODER_EVENT_BITMASK    = 0xC0; // events are the most significant two bits
+const uint8_t QDECODER_STATE_BITMASK    = 0x07; // states are in the least significant three bits
+
+const uint8_t HALF_STEP_STATE_TRANSITIONS[8][4] = {
+    // 0 = start
+    {QDECODER_STATE_MID,   QDECODER_STATE_CW_A,  QDECODER_STATE_CCW_A, QDECODER_STATE_START },
+    // 1 = CW_A
+    {QDECODER_EVENT_CW |
+     QDECODER_STATE_MID,   QDECODER_STATE_CW_A,  QDECODER_STATE_START, QDECODER_STATE_START },
+    // 2 = CW_B (unused in half-step mode)
+    {QDECODER_STATE_START, QDECODER_STATE_START, QDECODER_STATE_START, QDECODER_STATE_START },
+    // 3 = CW_C
+    {QDECODER_STATE_MID,   QDECODER_STATE_MID,   QDECODER_STATE_CW_C,  QDECODER_STATE_START | QDECODER_EVENT_CW },
+    // 4 = mid
+    {QDECODER_STATE_MID,   QDECODER_STATE_CCW_C, QDECODER_STATE_CW_C,  QDECODER_STATE_START },
+    // 5 = CCW_A
+    {QDECODER_EVENT_CCW |
+    QDECODER_STATE_MID,   QDECODER_STATE_START, QDECODER_STATE_CCW_A, QDECODER_STATE_START },
+    // 6 = CCW_B (unused in half-step mode)
+    {QDECODER_STATE_START, QDECODER_STATE_START, QDECODER_STATE_START, QDECODER_STATE_START },
+    // 7 = CCW_C
+    {QDECODER_STATE_MID,   QDECODER_STATE_CCW_C, QDECODER_STATE_MID,   QDECODER_STATE_START | QDECODER_EVENT_CCW},
+};
+
+const uint8_t FULL_STEP_STATE_TRANSITIONS[8][4] = {
+    // 0 = start
+    {QDECODER_STATE_START, QDECODER_STATE_CW_A,  QDECODER_STATE_CCW_A, QDECODER_STATE_START },
+    // 1 = CW_A
+    {QDECODER_STATE_CW_B,  QDECODER_STATE_CW_A,  QDECODER_STATE_START, QDECODER_STATE_START },
+    // 2 = CW_B
+    {QDECODER_STATE_CW_B,  QDECODER_STATE_CW_A,  QDECODER_STATE_CW_C,  QDECODER_STATE_START },
+    // 3 = CW_C
+    {QDECODER_STATE_CW_B,  QDECODER_STATE_START, QDECODER_STATE_CW_C,  QDECODER_STATE_START | QDECODER_EVENT_CW },
+    // 4 = mid (unused in full step mode ...)
+    {QDECODER_STATE_START, QDECODER_STATE_START, QDECODER_STATE_START, QDECODER_STATE_START },
+    // 5 = CCW_A
+    {QDECODER_STATE_CCW_B, QDECODER_STATE_START, QDECODER_STATE_CCW_A, QDECODER_STATE_START },
+    // 6 = CCW_B
+    {QDECODER_STATE_CCW_B, QDECODER_STATE_CCW_C, QDECODER_STATE_CCW_A, QDECODER_STATE_START },
+    // 7 = CCW_C
+    {QDECODER_STATE_CCW_B, QDECODER_STATE_CCW_C, QDECODER_STATE_START, QDECODER_STATE_START | QDECODER_EVENT_CCW },
+};

lib/qdec/license.txt

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2019 SimpleHacks ("Simple hacks for a simple life")
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

lib/qdec/readme

@@ -0,0 +1,2 @@
+This is a plain C header library lightly adapted from the SimpleHacks QDEC library.
+Find the original source here: https://github.com/SimpleHacks/QDEC

meson.build

@@ -55,8 +55,12 @@ minmea_src = ['lib/minmea/minmea.c']
 
 minmea_inc = ['lib/minmea/include']
 
+## QDEC, a very simple, header only, quadrature decoding library
+
+qdec_inc = ['lib/qdec/include']
+
 src = openrtx_src + minmea_src
-inc = openrtx_inc + rtos_inc + minmea_inc
+inc = openrtx_inc + rtos_inc + minmea_inc + qdec_inc
 
 ##
 ## Definitions

openrtx/include/interfaces/platform.h

@@ -101,7 +101,7 @@ float platform_getVolumeLevel();
 /**
  * This function reads and returns the current channel selector level.
  */
-uint8_t platform_getChSelector();
+int8_t platform_getChSelector();
 
 /**
  * This function reads and returns the current PTT status.

openrtx/include/settings.h

@@ -23,7 +23,7 @@
 
 typedef struct
 {
-    uint8_t valid[6];     // Should contain "OPNRTX" in a valid settings_t
+    uint8_t valid[7];     // Should contain "OPNRTX" in a valid settings_t
     uint8_t brightness;
     uint8_t contrast;
     int8_t utc_timezone;

platform/drivers/keyboard/keyboard_MDx.c

@@ -53,14 +53,22 @@ keyboard_t kbd_getKeys()
     keyboard_t keys = 0;
 
     /* Use absolute position knob to emulate left and right buttons */
-    static uint8_t old_pos = 0;
+    static int8_t old_pos = 0;
-    uint8_t new_pos = platform_getChSelector();
+    int8_t new_pos = platform_getChSelector();
     if (old_pos != new_pos)
     {
-        if (new_pos < old_pos)
+        int8_t diff = old_pos - new_pos;
+        if (diff < 0)
             keys |= KEY_LEFT;
-        else
+        else if (diff > 0)
             keys |= KEY_RIGHT;
+        else
+        {
+            if (old_pos < 0)
+                keys |= KEY_LEFT;
+            else
+                keys |= KEY_RIGHT;
+        }
         old_pos = new_pos;
     }
 

platform/targets/MD-UV3x0/platform.c

@@ -25,9 +25,11 @@
 #include <calibInfo_MDx.h>
 #include <interfaces/nvmem.h>
 #include <interfaces/rtc.h>
+#include <qdec.h>
 
 mduv3x0Calib_t calibration;
 hwInfo_t hwInfo;
+static int8_t knob_pos = 0;
 
 #ifdef ENABLE_BKLIGHT_DIMMING
 void _Z29TIM1_TRG_COM_TIM11_IRQHandlerv()
@@ -46,6 +48,42 @@ void _Z29TIM1_TRG_COM_TIM11_IRQHandlerv()
 }
 #endif
 
+/*
+ * Note that this interrupt handler currently assumes only the encoder will
+ * ever cause this interrupt to fire
+ */
+void _Z20EXTI15_10_IRQHandlerv()
+{
+    /* State storage */
+    static uint8_t last_state = 0;
+
+    /* Read curent pin state */
+    uint8_t pin_state = gpio_readPin(CH_SELECTOR_1)<<1 | gpio_readPin(CH_SELECTOR_0);
+    /* Look up next state */
+    uint8_t next_state = HALF_STEP_STATE_TRANSITIONS[last_state][pin_state];
+    /* update state for next call */
+    last_state = next_state & QDECODER_STATE_BITMASK;
+
+    /* Mask out events to switch on */
+    uint8_t event = next_state & QDECODER_EVENT_BITMASK;
+
+    /* Update file global knob_pos variable */
+    switch (event)
+    {
+        case QDECODER_EVENT_CW:
+            knob_pos++;
+            break;
+        case QDECODER_EVENT_CCW:
+            knob_pos--;
+            break;
+        default:
+            break;
+    }
+
+    /* Clear pin change flags */
+    EXTI->PR = EXTI_PR_PR11 | EXTI_PR_PR14;
+}
+
 void platform_init()
 {
     /* Configure GPIOs */
@@ -55,8 +93,19 @@ void platform_init()
     gpio_setMode(LCD_BKLIGHT, OUTPUT);
     gpio_clearPin(LCD_BKLIGHT);
 
-    gpio_setMode(CH_SELECTOR_0, INPUT);
+    gpio_setMode(CH_SELECTOR_0, INPUT_PULL_UP);
-    gpio_setMode(CH_SELECTOR_1, INPUT);
+    gpio_setMode(CH_SELECTOR_1, INPUT_PULL_UP);
+
+    EXTI->IMR  |= EXTI_IMR_MR11 | EXTI_IMR_MR14;
+    EXTI->RTSR |= EXTI_RTSR_TR11 | EXTI_RTSR_TR14;
+    EXTI->FTSR |= EXTI_FTSR_TR11 | EXTI_FTSR_TR14;
+
+    SYSCFG->EXTICR[2] |= SYSCFG_EXTICR3_EXTI11_PB;
+    SYSCFG->EXTICR[3] |= SYSCFG_EXTICR4_EXTI14_PE;
+
+    NVIC_ClearPendingIRQ(EXTI15_10_IRQn);
+    NVIC_SetPriority(EXTI15_10_IRQn, 15);
+    NVIC_EnableIRQ(EXTI15_10_IRQn);
 
     gpio_setMode(PTT_SW, INPUT_PULL_UP);
 
@@ -150,13 +199,13 @@ float platform_getVolumeLevel()
     return adc1_getMeasurement(1);
 }
 
-uint8_t platform_getChSelector()
+int8_t platform_getChSelector()
 {
-    static const uint8_t rsPositions[] = { 1, 4, 2, 3};
+    /*
-    int pos = gpio_readPin(CH_SELECTOR_0)
+     * The knob_pos variable is set in the EXTI15_10 interrupt handler
-            | (gpio_readPin(CH_SELECTOR_1) << 1);
+     * this is safe because interrupt nesting is not allowed.
-
+     */
-    return rsPositions[pos];
+    return knob_pos;
 }
 
 bool platform_getPttStatus()