From 0d7c2a6cc172b76e811fd47556a1f9945f3aadad Mon Sep 17 00:00:00 2001
From: rkcf <rkcf@rkcf.me>
Date: Mon, 20 Feb 2023 04:50:47 -0600
Subject: [PATCH] Feat: add i2c dac device connection test

Refs: #8
---
 src/main/esp32_eurorack_generic.c | 41 ++++++++++++++++++++++++++++---
 1 file changed, 37 insertions(+), 4 deletions(-)

diff --git a/src/main/esp32_eurorack_generic.c b/src/main/esp32_eurorack_generic.c
index fb55628..2882959 100644
--- a/src/main/esp32_eurorack_generic.c
+++ b/src/main/esp32_eurorack_generic.c
@@ -1,16 +1,26 @@
 #include <stdio.h>
+#include <stdint.h>
 
 #include "driver/gpio.h"
 #include "driver/i2c.h"
 #include "esp_err.h"
 #include "esp_log.h"
+#include "freertos/portmacro.h"
 #include "hal/i2c_types.h"
 
+/* DAC Peripheral Config */
 #define DAC_SCL_PIN 12
 #define DAC_SDA_PIN 13
 #define DAC_LDAC_PIN 14
 
-#define DAC_ADDR 0x60 /* I2C Address of DAC */
+#define DAC_ADDR 0x64 /* I2C Address of DAC */
+
+#define ACK_EN 0x1 /* Enable i2c acknowledgment check */
+#define ACK_DIS 0x0 /* Disable i2c acknowledgment check */
+#define ACK_VAL 0x0  /* i2c acknowledgment value */
+#define NACK_VAL 0x1 /* i2c negative-acknowledgment value */
+
+static const i2c_port_t I2C_MASTER_PORT = 0;
 
 static const char *TAG = "EERG";
 
@@ -21,7 +31,6 @@ static void dac_init(void)
   ESP_LOGI(TAG, "Initializing DAC I2C connection");
 
   /* Configure µC as I2C master */
-  i2c_port_t master_port = 0;
   i2c_config_t i2c_conf = {
     .mode = I2C_MODE_MASTER,
     .scl_io_num = DAC_SCL_PIN,
@@ -29,10 +38,10 @@ static void dac_init(void)
     .master.clk_speed = 400000 /* 400kHz for i2c fast mode */
 
   };
-  i2c_param_config(master_port, &i2c_conf);
+  i2c_param_config(I2C_MASTER_PORT, &i2c_conf);
 
   /* Install i2c driver */
-  ESP_ERROR_CHECK(i2c_driver_install(master_port, i2c_conf.mode, 0, 0, 0));
+  ESP_ERROR_CHECK(i2c_driver_install(I2C_MASTER_PORT, i2c_conf.mode, 0, 0, 0));
 
   /* Setup LDAC pin with GPIO. Tied low */
   gpio_reset_pin(DAC_LDAC_PIN);
@@ -40,8 +49,32 @@ static void dac_init(void)
   gpio_set_level(DAC_LDAC_PIN, 0);
 }
 
+/* Tests for acknowledgment of i2c DAC. Return ESP_OK if so */
+static esp_err_t dac_test(void)
+{
+  ESP_LOGI(TAG, "Testing I2C DAC");
+  /* Create i2c command handle */
+  i2c_cmd_handle_t cmd = i2c_cmd_link_create();
+  i2c_master_start(cmd);
+  i2c_master_write_byte(cmd, (DAC_ADDR << 1) | I2C_MASTER_READ, ACK_EN); /* R/W byte is LSB of DAC address */
+  i2c_master_stop(cmd);
+  esp_err_t ret = i2c_master_cmd_begin(I2C_MASTER_PORT, cmd, 10000 / portTICK_PERIOD_MS);
+  i2c_cmd_link_delete(cmd);
+
+  return ret;
+}
+
+/* Main application entrance */
 void app_main(void)
 {
   /* Initialize and configure I2C DAC */
   dac_init();
+
+  /* Test DAC */
+  esp_err_t ret = dac_test();
+  if (ret != ESP_OK){
+    ESP_LOGE(TAG, "Failed to initialize DAC");
+  } else {
+    ESP_LOGI(TAG, "Sucessfully initialized DAC");
+  }
 }