From 275e01269539610fad16d89049694c7e6776ae02 Mon Sep 17 00:00:00 2001
From: Martin Brodbeck <martin@brodbeck-online.de>
Date: Tue, 31 May 2022 09:47:29 +0200
Subject: [PATCH] ds18b20 code added

---
 CMakeLists.txt | 10 +++++--
 ds18b20.cpp    | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++
 ds18b20.h      | 23 ++++++++++++++++
 ds18b20.pio    | 44 ++++++++++++++++++++++++++++++
 gbmanager.cpp  |  1 +
 5 files changed, 148 insertions(+), 2 deletions(-)
 create mode 100644 ds18b20.cpp
 create mode 100644 ds18b20.h
 create mode 100644 ds18b20.pio

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6bbbf1f..ccf24b6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,7 +3,9 @@
 cmake_minimum_required(VERSION 3.13)
 
 set(CMAKE_C_STANDARD 11)
-set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD 20)
+
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wno-volatile")
 
 # Initialise pico_sdk from installed location
 # (note this can come from environment, CMake cache etc)
@@ -19,7 +21,7 @@ pico_sdk_init()
 
 # Add executable. Default name is the project name, version 0.1
 
-add_executable(gbmanager gbmanager.cpp lcd.cpp)
+add_executable(gbmanager gbmanager.cpp lcd.cpp ds18b20.cpp)
 
 pico_set_program_name(gbmanager "gbmanager")
 pico_set_program_version(gbmanager "0.1")
@@ -27,12 +29,16 @@ pico_set_program_version(gbmanager "0.1")
 pico_enable_stdio_uart(gbmanager 1)
 pico_enable_stdio_usb(gbmanager 0)
 
+pico_generate_pio_header(gbmanager ${CMAKE_CURRENT_LIST_DIR}/ds18b20.pio)
+
 # Add the standard library to the build
 target_link_libraries(gbmanager pico_stdlib)
 
 # Add any user requested libraries
 target_link_libraries(gbmanager
     hardware_i2c
+    hardware_gpio
+    hardware_pio
 )
 
 pico_add_extra_outputs(gbmanager)
diff --git a/ds18b20.cpp b/ds18b20.cpp
new file mode 100644
index 0000000..eee186f
--- /dev/null
+++ b/ds18b20.cpp
@@ -0,0 +1,72 @@
+#include "ds18b20.h"
+
+DS18B20::DS18B20(PIO pio, uint8_t gpio) : pio{pio}, gpio{gpio} {
+    uint offset = pio_add_program(pio, &ds18b20_program);
+    stateMachineIndex = pio_claim_unused_sm(pio, true);
+    pio_gpio_init(pio, gpio);
+    pio_sm_config c = ds18b20_program_get_default_config(offset);
+    sm_config_set_clkdiv_int_frac(&c, 255, 0);
+    sm_config_set_set_pins(&c, gpio, 1);
+    sm_config_set_out_pins(&c, gpio, 1);
+    sm_config_set_in_pins(&c, gpio);
+    sm_config_set_in_shift(&c, true, true, 8);
+    pio_sm_init(pio0, stateMachineIndex, offset, &c);
+    pio_sm_set_enabled(pio0, stateMachineIndex, true);
+}
+
+void DS18B20::writeBytes(uint8_t bytes[], int len) {
+    pio_sm_put_blocking(pio, stateMachineIndex, 250);
+    pio_sm_put_blocking(pio, stateMachineIndex, len - 1);
+    for (int i = 0; i < len; i++) {
+        pio_sm_put_blocking(pio, stateMachineIndex, bytes[i]);
+    }
+}
+
+void DS18B20::readBytes(uint8_t bytes[], int len) {
+    pio_sm_put_blocking(pio, stateMachineIndex, 0);
+    pio_sm_put_blocking(pio, stateMachineIndex, len - 1);
+    for (int i = 0; i < len; i++) {
+        bytes[i] = pio_sm_get_blocking(pio, stateMachineIndex) >> 24;
+    }
+}
+
+void DS18B20::convert() {
+    uint8_t d[2] = {0xCC, 0x44};
+    writeBytes(d, 2);
+}
+
+uint8_t DS18B20::crc8(uint8_t *data, uint8_t len) {
+    uint8_t i;
+    uint8_t j;
+    uint8_t temp;
+    uint8_t databyte;
+    uint8_t crc = 0;
+
+    for (i = 0; i < len; i++) {
+        databyte = data[i];
+        for (j = 0; j < 8; j++) {
+            temp = (crc ^ databyte) & 0x01;
+            crc >>= 1;
+            if (temp)
+                crc ^= 0x8C;
+            databyte >>= 1;
+        }
+    }
+
+    return crc;
+}
+
+float DS18B20::getTemperature() {
+    uint8_t d[2] = {0xCC, 0xBE};
+    writeBytes(d, 2);
+    uint8_t data[9];
+    readBytes(data, 9);
+    uint8_t crc = crc8(data, 9);
+    if (crc != 0)
+        return -2000;
+    int t1 = data[0];
+    int t2 = data[1];
+    int16_t temp1 = (t2 << 8 | t1);
+    volatile float temp = (float)temp1 / 16;
+    return temp;
+}
\ No newline at end of file
diff --git a/ds18b20.h b/ds18b20.h
new file mode 100644
index 0000000..9c2f68d
--- /dev/null
+++ b/ds18b20.h
@@ -0,0 +1,23 @@
+#ifndef DS18B20_H
+#define DS18B20_H
+
+#include "ds18b20.pio.h"
+#include "hardware/gpio.h"
+#include "pico/stdlib.h"
+
+class DS18B20 {
+  public:
+    DS18B20(PIO pio, uint8_t gpio);
+    float getTemperature();
+    void convert();
+
+  private:
+    uint8_t crc8(uint8_t *data, uint8_t len);
+    void writeBytes(uint8_t bytes[], int len);
+    void readBytes(uint8_t bytes[], int len);
+    PIO pio;
+    uint8_t gpio;
+    uint stateMachineIndex;
+};
+
+#endif
\ No newline at end of file
diff --git a/ds18b20.pio b/ds18b20.pio
new file mode 100644
index 0000000..eb23d8f
--- /dev/null
+++ b/ds18b20.pio
@@ -0,0 +1,44 @@
+
+.program ds18b20 
+.wrap_target
+again:
+  pull block
+  mov x, osr
+  jmp !x, read
+
+write:  set pindirs, 1 
+  set pins, 0  
+loop1: 
+    jmp x--,loop1
+set pindirs, 0 [31]
+wait 1 pin 0 [31]
+
+  pull block
+  mov x, osr
+bytes1:
+   pull block
+  set y, 7    
+  set pindirs, 1 
+bit1:
+  set pins, 0 [1]
+  out pins,1 [31]
+    set pins, 1 [20]
+   jmp y--,bit1
+jmp x--,bytes1
+
+set pindirs, 0 [31]
+jmp again
+
+read:
+  pull block
+  mov x, osr
+bytes2:
+  set y, 7
+bit2:
+  set pindirs, 1 
+  set pins, 0 [1]  
+  set pindirs, 0 [5]
+  in pins,1 [10]   
+jmp y--,bit2
+jmp x--,bytes2
+.wrap
diff --git a/gbmanager.cpp b/gbmanager.cpp
index c051d98..4f4e114 100644
--- a/gbmanager.cpp
+++ b/gbmanager.cpp
@@ -4,6 +4,7 @@
 #include "pico/stdlib.h"
 
 #include "lcd.h"
+#include "ds18b20.h"
 
 constexpr uint I2C_SDA_PIN = 26;
 constexpr uint I2C_SCL_PIN = 27;