Added AHT10 demo.

CMakeLists.txt

@@ -3,4 +3,5 @@ cmake_minimum_required(VERSION 3.10)
 project(usbsio_demos)
 
 add_subdirectory(libusbsio)
-add_subdirectory(demos/i2cdetect)
+add_subdirectory(demos/i2cdetect)
+add_subdirectory(demos/dht_sensor)

demos/dht_sensor/CMakeLists.txt

@@ -0,0 +1,10 @@
+cmake_minimum_required(VERSION 3.10)
+
+project(usbsio_dhtsensor)
+
+set(USBSIO_DHT_SRCS
+    "src/main.c"
+)
+
+add_executable(${PROJECT_NAME} ${USBSIO_DHT_SRCS})
+target_link_libraries(${PROJECT_NAME} PRIVATE "usbsio")

demos/dht_sensor/src/main.c

@@ -0,0 +1,146 @@
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+/* USBSIO header */
+#include <lpcusbsio.h>
+
+#define NXP_VID     0x1FC9
+#define MCULINK_PID 0x0143
+
+static bool s_running = true;
+
+static int aht10_measure(LPC_HANDLE handle, uint8_t slave_addr, double *temp, double *hum);
+
+static void signal_handler(int sig);
+
+int main(int argc, const char *argv) {
+    int        ret;
+    LPC_HANDLE dev_handle;
+    LPC_HANDLE i2c_handle;
+
+    fprintf(stdout, "USBSIO example - AHT10\n");
+
+    signal(SIGINT, signal_handler);
+    signal(SIGTERM, signal_handler);
+
+    /* Find all SIO devices. */
+    ret = LPCUSBSIO_GetNumPorts(NXP_VID, MCULINK_PID);
+    if (ret == 0) {
+        fprintf(stderr, "No MCU-Link devices found.\n");
+        return -1;
+    }
+
+    /* Open device */
+    dev_handle = LPCUSBSIO_Open(0); /* For now, open the first device available. */
+    if (dev_handle == NULL) {
+        fprintf(stderr, "Failed to open device #0\n");
+        return -2;
+    }
+
+    fprintf(stdout, "%s\n", LPCUSBSIO_GetVersion(dev_handle));
+
+    I2C_PORTCONFIG_T i2c_cfg = {
+        .ClockRate = I2C_CLOCK_FAST_MODE,
+        .Options   = 0U,
+    };
+
+    i2c_handle = I2C_Open(dev_handle, &i2c_cfg, 0);
+
+    double temperature = 0.00;
+    double humidity    = 0.00;
+
+    while (s_running) {
+        int ret = aht10_measure(i2c_handle, 0x38, &temperature, &humidity);
+        if(ret < 0) {
+            fprintf(stderr, "Sensor communication error.\n");
+        }
+        else {
+            fprintf(stdout, "Temperature: %.2fC, humidity: %.2f%%\n", temperature, humidity);
+        }
+
+        usleep(100 * 1000);
+    }
+}
+
+static int aht10_measure(LPC_HANDLE handle, uint8_t slave_addr, double *temp, double *hum) {
+    uint8_t tx_buffer[3] = {0x71, 0x00, 0x00};
+    uint8_t rx_buffer[6];
+
+    I2C_FAST_XFER_T xfer = {
+        .slaveAddr = slave_addr,
+        .txSz      = 1U,
+        .txBuff    = tx_buffer,
+        .rxSz      = 1U,
+        .rxBuff    = rx_buffer,
+        .options   = 0U,
+    };
+
+    usleep(40 * 1000);
+
+    int ret = I2C_FastXfer(handle, &xfer);
+    if (ret < 0) {
+        I2C_Reset(handle);
+        return ret;
+    }
+
+    if ((rx_buffer[0] & 0x08) == 0U) {
+        /* BIT3 indicates AHT10 not calibrated, send initialization command */
+        tx_buffer[0] = 0xE1;
+        tx_buffer[1] = 0x08;
+        tx_buffer[2] = 0x00;
+
+        xfer.txSz = 0x03;
+        xfer.rxSz = 0x00;
+
+        ret = I2C_FastXfer(handle, &xfer);
+        if (ret < 0) {
+            I2C_Reset(handle);
+            return ret;
+        }
+
+        usleep(40 * 1000);
+    }
+
+    tx_buffer[0] = 0xAC;
+    tx_buffer[1] = 0x33;
+    tx_buffer[2] = 0x00;
+
+    xfer.txSz = 0x03;
+    xfer.rxSz = 0x00;
+
+    ret = I2C_FastXfer(handle, &xfer);
+    if (ret < 0) {
+        I2C_Reset(handle);
+        return ret;
+    }
+
+    usleep(80 * 1000);
+
+    tx_buffer[0] = 0x71;
+    xfer.txSz    = 0x01;
+    xfer.rxSz    = 0x06;
+
+    ret = I2C_FastXfer(handle, &xfer);
+    if (ret < 0) {
+        I2C_Reset(handle);
+        return ret;
+    }
+
+    uint32_t humid_raw = rx_buffer[1] << 12U;
+    humid_raw |= rx_buffer[2] << 4U;
+    humid_raw |= rx_buffer[3] >> 4U;
+
+    uint32_t temp_raw = (rx_buffer[3] & 0x0FU) << 16U;
+    temp_raw |= rx_buffer[4] << 8U;
+    temp_raw |= rx_buffer[5];
+
+    *hum  = (double)humid_raw * 100.0 / 1048576.0;
+    *temp = ((double)temp_raw * 200.0 / 1048576.0) - 50.0;
+
+    return ret;
+}
+
+static void signal_handler(int sig) { s_running = false; }

demos/i2cdetect/src/main.c

@@ -57,8 +57,8 @@ static int i2c_detect(LPC_HANDLE handle, uint8_t port_num, uint8_t start_addr, u
                       enum I2C_ClockRate_t rate) {
     fprintf(stdout, "WARNING! This program can confuse your I2C bus, cause data loss and worse!\n");
     fprintf(stdout,
-            "WARNING! Current MCU-Link firmware has a bug which causes device to be unresponsive\n"
-            "         if I2C bus timeout due to lack of external pull-up resistors.\n"
+            "WARNING! MCU-Link firmware under a specific version has a bug which\n"
+            "         causes device to be unresponsive if this application exits abnormally.\n"
             "         In case that happens, don't panic, just re-plug the MCU-Link\n"
             "         and the device will be available again.\n");
 

libusbsio

@@ -1 +1 @@
-Subproject commit 60907768d02c589a6846cf5f03480acda45eb8ee
+Subproject commit ea9afb6c50c81d766b14004ef9f0a3c1283482a5