diff --git a/c/common/spidriver.c b/c/common/spidriver.c
index f2cf290..33989b7 100644
--- a/c/common/spidriver.c
+++ b/c/common/spidriver.c
@@ -280,6 +280,7 @@ void spi_getstatus(SPIDriver *sd)
     &sd->cs,
     &sd->ccitt_crc
     );
+  sd->mode = 0;
 }
 
 void spi_sel(SPIDriver *sd)
@@ -308,6 +309,15 @@ void spi_setb(SPIDriver *sd, char v)
   sd->b = v;
 }
 
+void spi_setmode(SPIDriver *sd, char m)
+{
+  if (strcmp(sd->model, "spidriver2") == 0) {
+    char cmd[2] = {'m', m};
+    writeToSerialPort(sd->port, cmd, 2);
+    sd->mode = m;
+  }
+}
+
 void spi_write(SPIDriver *sd, const char bytes[], size_t nn)
 {
   size_t i;
@@ -416,6 +426,12 @@ int spi_commands(SPIDriver *sd, int argc, char *argv[])
         spi_setb(sd, token[0]);
       break;
 
+    case 'm':
+      token = argv[++i];
+      if (token != NULL)
+        spi_setmode(sd, token[0]);
+      break;
+
     default:
     badcommand:
       fprintf(stderr, "Bad command '%s'\n", token);
@@ -429,6 +445,7 @@ int spi_commands(SPIDriver *sd, int argc, char *argv[])
       fprintf(stderr, "  r N   read N bytes from SPI\n");
       fprintf(stderr, "  a 0/1 Set A line\n");
       fprintf(stderr, "  b 0/1 Set B line\n");
+      fprintf(stderr, "  m 0-3 Set SPI mode (spidriver2 only)\n");
       fprintf(stderr, "\n");
 
       return 1;
diff --git a/c/common/spidriver.h b/c/common/spidriver.h
index 541af65..09de108 100644
--- a/c/common/spidriver.h
+++ b/c/common/spidriver.h
@@ -19,6 +19,7 @@ typedef struct {
             current_ma,   // device current (mA)
             temp_celsius; // temperature (C)
   unsigned int a, b, cs;  // state of three output lines
+  unsigned int mode;      // SPI mode
   unsigned int
             ccitt_crc,    // Hardware CCITT CRC
             e_ccitt_crc;  // Host CCITT CRC, should match