diff --git a/app/src/main/c/glue.c b/app/src/main/c/glue.c
index dcef42a..c13cacd 100644
--- a/app/src/main/c/glue.c
+++ b/app/src/main/c/glue.c
@@ -1,9 +1,13 @@
+#include "glue.h"
+
 #include <stdint.h>
 #include <stdio.h>
 
 #include "../../../../clib/proxmark3/include/usb_cmd.h"
 #include "pm3dev.h"
 
+void UsbCommandReceived(UsbCommand *UC);
+
 void ShowGraphWindow(void) { printf("pm3jni: ShowGraphWindow called (stub)"); }
 void HideGraphWindow(void) { printf("pm3jni: HideGraphWindow called (stub)"); }
 void RepaintGraphWindow(void) { printf("pm3jni: RepaintGraphWindow called (stub)"); }
@@ -63,3 +67,11 @@ const char *get_my_executable_directory(void) {
     printf("pm3jni: get_my_executable_directory called (stub)");
     return ".";
 }
+
+size_t pm3glue_usbcmd_size(void) {
+    return sizeof(UsbCommand);
+}
+
+void pm3glue_recv_cmd(void *cmd) {
+    UsbCommandReceived(cmd);
+}
diff --git a/app/src/main/c/glue.h b/app/src/main/c/glue.h
new file mode 100644
index 0000000..2b09850
--- /dev/null
+++ b/app/src/main/c/glue.h
@@ -0,0 +1,7 @@
+#include <stddef.h>
+
+#ifndef PROXMARK3_GLUE_H
+#define PROXMARK3_GLUE_H
+size_t pm3glue_usbcmd_size(void);
+void pm3glue_recv_cmd(void *);
+#endif // PROXMARK3_GLUE_H
diff --git a/app/src/main/c/pm3dev.c b/app/src/main/c/pm3dev.c
index 4fe7b55..a9a3489 100644
--- a/app/src/main/c/pm3dev.c
+++ b/app/src/main/c/pm3dev.c
@@ -1,74 +1,69 @@
+#include "pm3dev.h"
+
 #include <malloc.h>
 #include <stdio.h>
 #include <unistd.h>
 #include <sys/wait.h>
 
-#include "pm3dev.h"
 #include "pm3uart.h"
 #include "pm3util.h"
 #include "pm3relayd.h"
+#include "glue.h"
 
 enum { DEVTYPE_INVALID, DEVTYPE_DIRECT, DEVTYPE_RELAYED, DEVTYPE_TEST }
         pm3dev_type = DEVTYPE_INVALID;
 int pm3dev_fd = -1;
 int pm3dev_relayd_outfd = -1;
-int pm3dev_relayd_infd = -1;
+int pm3dev_relayd_child_stdoutfd = -1;
 pid_t pm3dev_relayd_pid = -1;
 char *pm3dev_relayd_path = NULL;
 int *pm3dev_thread_quit = NULL;
 
 int pm3dev_relay_run(const char *devpath) {
     if (!pm3dev_relayd_path) {
-        fprintf(stderr, "pm3dev: relayd_path unset\n");
+        fprintf(stderr, "pm3dev_relay_run: relayd_path unset\n");
         return -1;
     }
 
-    int outp[2], inp[2];
-    if (pipe(outp) == -1) {
-        perror("pm3dev: pipe(outp)");
+    if (pm3dev_relayd_child_stdoutfd == -1) {
+        fprintf(stderr, "pm3dev_relay_run: relayd_child_stdoutfd unset\n");
         return -1;
     }
-    if (pipe(inp) == -1) {
-        perror("pm3dev: pipe(inp)");
-        close(outp[0]);
-        close(outp[1]);
+
+    int outp[2];
+    if (pipe(outp) == -1) {
+        perror("pm3dev_relay_run: pipe(outp)");
         return -1;
     }
 
     char sharg[1024] = {0};
     if (snprintf(sharg, sizeof(sharg), "exec %s %s", pm3dev_relayd_path, devpath) > sizeof(sharg)) {
-        fprintf(stderr, "pm3dev: pm3dev_relay_run: snprintf buffer too small\n");
+        fprintf(stderr, "pm3dev_relay_run: pm3dev_relay_run: snprintf buffer too small\n");
         close(outp[0]);
         close(outp[1]);
-        close(inp[0]);
-        close(inp[1]);
         return -1;
     }
 
     const char *const argv[] = {"su", "root", "sh", "-c", sharg, 0};
-    fprintf(stderr, "pm3dev: pm3dev_relay_run: %s\n", sharg);
+    fprintf(stderr, "pm3dev_relay_run: pm3dev_relay_run: %s\n", sharg);
     pid_t pid = fork();
     if (pid == 0) {
         if (dup2(outp[0], STDIN_FILENO) != STDIN_FILENO ||
-                dup2(inp[1], STDOUT_FILENO) != STDOUT_FILENO) {
-            perror("pm3dev: pm3dev_relay_run: dup2");
+                dup2(pm3dev_relayd_child_stdoutfd, STDOUT_FILENO) != STDOUT_FILENO) {
+            perror("pm3dev_relay_run: pm3dev_relay_run: dup2");
             _exit(-1);
         }
         execvp("su", (char *const *) argv);
         _exit(-1);
     } else if (pid > 0) {
         close(outp[0]);
-        close(inp[1]);
         pm3dev_relayd_pid = pid;
         pm3dev_relayd_outfd = outp[1];
-        pm3dev_relayd_infd = inp[0];
         pm3dev_type = DEVTYPE_RELAYED;
     } else {
-        perror("pm3dev: vfork");
+        perror("pm3dev_relay_run: vfork");
         close(outp[0]);
         close(outp[1]);
-        close(inp[0]);
-        close(inp[1]);
         return -1;
     }
 
@@ -78,27 +73,50 @@ int pm3dev_relay_run(const char *devpath) {
 void pm3dev_relay_shutdown(void) {
     enum pm3relayd_cmd cmd = RELAYDCMD_EXIT;
     if (pm3util_write(pm3dev_relayd_outfd, &cmd, sizeof(cmd)) == -1) {
-        perror("pm3dev: write(outfd) for RELAYDCMD_EXIT");
+        perror("pm3dev_relay_shutdown: write(outfd) for RELAYDCMD_EXIT");
     }
 }
 
 int pm3dev_relay_send(const uint8_t *bytes, const size_t size) {
     enum pm3relayd_cmd cmd = RELAYDCMD_SEND;
     if (pm3util_write(pm3dev_relayd_outfd, &cmd, sizeof(cmd)) == -1) {
-        perror("pm3dev: write(outfd) for RELAYDCMD_SEND");
+        perror("pm3dev_relay_send: write(outfd) for RELAYDCMD_SEND");
         return -1;
     }
     if (pm3util_write(pm3dev_relayd_outfd, &size, sizeof(size)) == -1) {
-        perror("pm3dev: write(outfd) for RELAYDCMD_SEND size");
+        perror("pm3dev_relay_send: write(outfd) for RELAYDCMD_SEND size");
         return -1;
     }
     if (pm3util_write(pm3dev_relayd_outfd, bytes, size) == -1) {
-        perror("pm3dev: write(outfd) for RELAYDCMD_SEND data");
+        perror("pm3dev_relay_send: write(outfd) for RELAYDCMD_SEND data");
         return -1;
     }
     return 0;
 }
 
+int pm3dev_relay_thread(void) {
+    size_t cmdsize = pm3glue_usbcmd_size();
+    void *buf = malloc(cmdsize);
+    if (!buf) {
+        perror("pm3dev_relay_thread: malloc");
+    }
+
+    int inp[2];
+    if (pipe(inp) == -1) {
+        perror("pm3dev_relay_thread: pipe(inp)");
+        return -1;
+    }
+    pm3dev_relayd_child_stdoutfd = inp[1];
+
+    while (1) {
+        if (pm3util_read(inp[0], buf, cmdsize) == -1) {
+            perror("pm3dev_relay_thread: read");
+            return -1;
+        }
+        pm3glue_recv_cmd(buf);
+    }
+}
+
 int pm3dev_change(const char *newpath) {
     switch (pm3dev_type) {
         case DEVTYPE_DIRECT:
@@ -116,14 +134,21 @@ int pm3dev_change(const char *newpath) {
     }
 
     if (*newpath) {
+        /* TODO: implement direct reading (need to spawn a thread to read from ttyACM
+         * TODO: and call UsbCommandReceived)
+         */
+#if 0
         int newfd = pm3uart_open(newpath);
         if (newfd == -1) {
-            return pm3dev_relay_run(newpath);
+#endif
+        return pm3dev_relay_run(newpath);
+#if 0
         } else {
             pm3dev_fd = newfd;
             pm3dev_type = DEVTYPE_DIRECT;
             return 0;
         }
+#endif
     } else {
         pm3dev_type = DEVTYPE_TEST;
         return 0;
diff --git a/app/src/main/c/pm3dev.h b/app/src/main/c/pm3dev.h
index f9826c4..da036ac 100644
--- a/app/src/main/c/pm3dev.h
+++ b/app/src/main/c/pm3dev.h
@@ -4,7 +4,9 @@
 #ifndef PROXMARK3_PM3DEV_H
 #define PROXMARK3_PM3DEV_H
 extern char *pm3dev_relayd_path;
+extern int pm3dev_relayd_child_stdoutfd;
 
 int pm3dev_change(const char *);
 int pm3dev_write(const uint8_t *, size_t);
+int pm3dev_relay_thread(void);
 #endif // PROXMARK3_PM3DEV_H
diff --git a/app/src/main/c/pm3jni.c b/app/src/main/c/pm3jni.c
index d9b9b3d..85ed857 100644
--- a/app/src/main/c/pm3jni.c
+++ b/app/src/main/c/pm3jni.c
@@ -86,3 +86,9 @@ JNIEXPORT void JNICALL Java_angelsl_androidapp_proxmark3_interop_Proxmark3_jniSe
     pm3dev_relayd_path = pathcopy;
     (*env)->ReleaseStringUTFChars(env, path_, path);
 }
+
+JNIEXPORT void JNICALL Java_angelsl_androidapp_proxmark3_interop_Proxmark3_jniUsbInWorker(JNIEnv *env, jclass type) {
+    if (pm3dev_relay_thread() == -1) {
+        jni_throw(env, "Relay thread quit");
+    }
+}
diff --git a/app/src/main/java/angelsl/androidapp/proxmark3/interop/Proxmark3.java b/app/src/main/java/angelsl/androidapp/proxmark3/interop/Proxmark3.java
index 6d0ba9f..ff62b2c 100644
--- a/app/src/main/java/angelsl/androidapp/proxmark3/interop/Proxmark3.java
+++ b/app/src/main/java/angelsl/androidapp/proxmark3/interop/Proxmark3.java
@@ -22,6 +22,12 @@ public void run() {
                     jniStdoutWorker();
                 }
             }).start();
+        new Thread(new Runnable() {
+            @Override
+            public void run() {
+                jniUsbInWorker();
+            }
+        }).start();
     }
 
     public static void init(Context c) {
@@ -65,6 +71,7 @@ private static void dispatchOutput(String n) {
     }
 
     private static native void jniStdoutWorker();
+    private static native void jniUsbInWorker();
     private static native int jniExecCommand(String command);
     private static native void jniChangeDevice(String path);
     private static native void jniSetRelaydPath(String path);