Sets MAC address to a random static value

code/b-parasite/Makefile

@@ -308,3 +308,7 @@ SDK_CONFIG_FILE := ../config/sdk_config.h
 CMSIS_CONFIG_TOOL := $(SDK_ROOT)/external_tools/cmsisconfig/CMSIS_Configuration_Wizard.jar
 sdk_config:
 	java -jar $(CMSIS_CONFIG_TOOL) $(SDK_CONFIG_FILE)
+
+.PHONY: flash_loop
+flash_loop:
+	while [ 1 ]; do make flash && break; done

code/b-parasite/config/prst_config.h

@@ -15,15 +15,18 @@
 #define PRST_ADC_DEBUG 0
 
 // BLE.
-#define PRST_BLE_ADV_NAME "prst"
 // Prints out BLE debug info, such as the final encoded advertisement packet.
 #define PRST_BLE_DEBUG 0
+#define PRST_BLE_MAC_ADDR_LSB0 0xaa
+#define PRST_BLE_MAC_ADDR_LSB1 0xbb
+#define PRST_BLE_ADV_TIME_IN_MS 200
+#define PRST_BLE_ADV_NAME "prst aabb"
 
 // PWM.
 #define PRST_PWM_PIN NRF_GPIO_PIN_MAP(0, 5)
 #define PRST_FAST_DISCH_PIN NRF_GPIO_PIN_MAP(1, 10)
 
 // SHT3C temp/humidity sensor.
-#define PRST_SHT3C_DEBUG 1
+#define PRST_SHT3C_DEBUG 0
 
 #endif  // _PRST_CONFIG_H_

code/b-parasite/src/main.c

@@ -71,7 +71,7 @@ static void rtc_callback() {
                            temp_humi.humidity, soil_read.relative);
   NRF_LOG_FLUSH();
   prst_adv_start();
-  nrf_delay_ms(200);
+  nrf_delay_ms(PRST_BLE_ADV_TIME_IN_MS);
   prst_adv_stop();
   nrf_gpio_pin_clear(PRST_LED_PIN);
   NRF_LOG_FLUSH();

code/b-parasite/src/prst/ble.c

@@ -23,7 +23,7 @@
 #define NON_CONNECTABLE_ADV_INTERVAL MSEC_TO_UNITS(100, UNIT_0_625_MS)
 
 // Sensor data payload that will go into the advertisement message.
-#define SERVICE_DATA_LEN 16
+#define SERVICE_DATA_LEN 12
 static uint8_t service_data[SERVICE_DATA_LEN];
 
 // Stores the encoded advertisement data. As per BLE spec, 31 bytes max.
@@ -61,6 +61,17 @@ static uint8_t adv_handle_ = BLE_GAP_ADV_SET_HANDLE_NOT_SET;
 // Advertisement parameters.
 static ble_gap_adv_params_t adv_params_;
 
+// Stores the MAC address & type.
+// We're using a random static MAC address, which has the following constraints:
+// 1. Two most significant bits are set to 1;
+// 2. The remaining bits should not _all_ be set to 0;
+// 2. The remaining bits should not _all_ be set to 1;
+static const ble_gap_addr_t gap_addr_ = {
+    .addr_type = BLE_GAP_ADDR_TYPE_RANDOM_STATIC,
+    // Least significant bytes first.
+    .addr = {PRST_BLE_MAC_ADDR_LSB0, PRST_BLE_MAC_ADDR_LSB1, 0xca, 0xf0, 0xca,
+             0xf0}};
+
 static void init_advertisement_data() {
   // We'll just broadcast our data, so we disallow connections and scan
   // requests.
@@ -81,6 +92,8 @@ static void init_advertisement_data() {
   uint32_t err_code =
       sd_ble_gap_adv_set_configure(&adv_handle_, &gap_adv_data_, &adv_params_);
   APP_ERROR_CHECK(err_code);
+
+  APP_ERROR_CHECK(sd_ble_gap_addr_set(&gap_addr_));
 }
 
 void prst_ble_init() {

code/b-parasite/src/prst/shtc3.c

@@ -6,6 +6,8 @@
 #include <nrf_log.h>
 #include <nrf_log_ctrl.h>
 
+#include "prst_config.h"
+
 static const nrf_drv_twi_t twi_ = NRF_DRV_TWI_INSTANCE(0);
 static nrf_drv_twi_config_t twi_config_ = NRF_DRV_TWI_DEFAULT_CONFIG;
 
@@ -54,9 +56,9 @@ prst_shtc3_read_t prst_shtc3_read() {
                            .humidity = humi};
 #if PRST_SHT3C_DEBUG
   NRF_LOG_INFO("[sht3c] Read temp: " NRF_LOG_FLOAT_MARKER " oC",
-               NRF_LOG_FLOAT((float)temp_humi.temp_millicelcius / 1000.0));
+               NRF_LOG_FLOAT((float)ret.temp_millicelcius / 1000.0));
   NRF_LOG_INFO("[sht3c] Read humi: " NRF_LOG_FLOAT_MARKER " %%",
-               NRF_LOG_FLOAT(100.0 * temp_humi.humidity / (1 << 16)));
+               NRF_LOG_FLOAT(100.0 * ret.humidity / (1 << 16)));
 #endif
   return ret;
 }