commit 7ec406c5af692b9c99ae9ed0c7fb5ba648a0a71e
Author: Morgan 'ARR\!' Allen <morganrallen@gmail.com>
Date:   Thu Oct 14 22:13:37 2021 -0700

    a barely functional driver. hooray!

diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..d57deab
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,5 @@
+idf_component_register(SRCS
+  "main/dfplayermini.c"
+
+  INCLUDE_DIRS "include"
+)
diff --git a/include/dfplayermini.h b/include/dfplayermini.h
new file mode 100644
index 0000000..d91210f
--- /dev/null
+++ b/include/dfplayermini.h
@@ -0,0 +1,8 @@
+#ifndef __DFPLAYERMINI_H_
+#define __DFPLAYERMINI_H_
+
+#include <stdint.h>
+
+uint8_t dfplayermini_init();
+
+#endif
diff --git a/main/dfplayermini.c b/main/dfplayermini.c
new file mode 100644
index 0000000..7a28ed8
--- /dev/null
+++ b/main/dfplayermini.c
@@ -0,0 +1,130 @@
+#include "stdint.h"
+#include "driver/uart.h"
+#include "dfplayermini.h"
+
+#define BUF_SIZE    (1024)
+#define PACKET_LEN  (8)
+#define BYTE_START  (0x7E)
+#define BYTE_END    (0xEF)
+
+
+struct DFPlayerMini {
+  uart_config_t *uart_config;
+} dfplayermini;
+
+/*
+ * 0x7E START
+ * 0xFF VER
+ * 0x06 LEN
+ * 0x00 ACK
+ * 0x01 CMD
+ * 0x00 PARAM-hi
+ * 0x00 PARAM-lo
+ * 0x00 CHECK-hi
+ * 0x00 CHECK-lo
+ * 0xEF FIN
+ */
+uint8_t packet[] = { 0x7E, 0xFF, 0x06, 0x00, 0x01, 0x00, 0x00, 0xEF };
+
+uint8_t send_packet(uint8_t cmd, uint8_t arg_low, uint8_t arg_high) {
+  uint8_t i = 0;
+  uint16_t sum = 0;
+
+  packet[3] = cmd;
+  packet[4] = 1;
+  packet[5] = arg_high;
+  packet[6] = arg_low;
+
+  for(i = 1; i < 7; i++) {
+    sum += packet[i];
+  }
+
+  //packet[7] = -sum << 8;
+  //packet[8] = -sum;
+
+  return uart_write_bytes(UART_NUM_1, (const char*)&packet, PACKET_LEN);
+}
+
+uint8_t set_volume(uint8_t vol) {
+  return send_packet(0x06, vol, 0);
+}
+ 
+void dfplayermini_uart_read_task(void *arg) {
+  setvbuf(stdout, NULL, _IONBF, 0);
+
+  uint8_t buf[PACKET_LEN];
+  uint8_t err;
+  uint8_t idx = 0;
+  uint8_t inited = 0;
+  uint8_t timeout = 1;
+
+  while(true) {
+    int len = uart_read_bytes(UART_NUM_1, &buf[idx], 1, 20 / portTICK_RATE_MS);
+
+    if(len == 0) {
+      if(inited == 0 && timeout++ == 0) {
+        printf("timeout, sending reset\n");
+        send_packet(0x0C, 0, 0);
+      }
+
+      continue;
+    }
+
+    if(buf[0] == BYTE_START) {
+      printf("0x%02X ", buf[idx]);
+
+      idx++;
+      //printf("got start byte\n");
+    }
+
+    if(buf[idx - 1] == BYTE_END) {
+      printf("\n");
+
+      switch(buf[3]) {
+        case 0x3F:
+          printf("player ready\n");
+          inited = 1;
+
+          //send_packet(0x0C, 0, 0);
+          //vTaskDelay(10 / portTICK_RATE_MS);
+
+          //if(!(err = send_packet(0x09, 1, 0))) {
+            //printf("Failed to set play source: %d\n", err);
+          //}
+
+          if(!(err = set_volume(10))) {
+            printf("Failed to set volume: %d\n", err);
+          }
+
+          vTaskDelay(100 / portTICK_RATE_MS);
+
+          send_packet(0x03, 0, 0);
+
+          break;
+      }
+
+      idx = 0;
+    }
+  }
+}
+
+uint8_t dfplayermini_init() {
+  uart_config_t uart_config = {
+    .baud_rate = 9600,
+    .data_bits = UART_DATA_8_BITS,
+    .parity    = UART_PARITY_DISABLE,
+    .stop_bits = UART_STOP_BITS_1,
+    .flow_ctrl = UART_HW_FLOWCTRL_DISABLE,
+    .source_clk = UART_SCLK_APB,
+  };
+
+  dfplayermini.uart_config = &uart_config;
+
+  uart_driver_install(UART_NUM_1, BUF_SIZE * 2, 0, 0, NULL, 0);
+  uart_param_config(UART_NUM_1, dfplayermini.uart_config);
+  uart_set_pin(UART_NUM_1, 13, 34, -1, -1);
+
+  xTaskCreate(dfplayermini_uart_read_task, "dfplayermini_uart_read_task", 2048, NULL, 10, NULL);
+
+  return 0;
+}