diff --git a/src/Row.h b/src/Row.h
index a44c784..74add18 100644
--- a/src/Row.h
+++ b/src/Row.h
@@ -11,8 +11,12 @@
 
 /*
 strobePin has one of two formats:
- * if refScanner a Scanner_uC, then strobePin is an Arduino pin number connected to this row
- * otherwise strobePin is bit pattern, 1 indicating an IC pin connected to this row
+1. if strobe pin is on uC (Scanner_uC or Scanner_ShiftRegsPISOMultiRow),
+    then strobePin is an Arduino pin number connected to this row.
+2. if strobe pin is on I/O expander (Scanner_IOE), then strobePin is bit pattern,
+    1 indicating the I/O expander pin connected to this row
+
+todo instantiation examples - here or in Scanner?
 */
 class Row
 {
diff --git a/src/Scanner_ShiftRegsPISOMultiRow.cpp b/src/Scanner_ShiftRegsPISOMultiRow.cpp
index e29972b..a9125d4 100644
--- a/src/Scanner_ShiftRegsPISOMultiRow.cpp
+++ b/src/Scanner_ShiftRegsPISOMultiRow.cpp
@@ -21,7 +21,7 @@ Initializes shift register's shift/load pin.
 */
 void Scanner_ShiftRegsPISOMultiRow::begin()
 {
-    SPI.begin();
+    SPI.begin(); //todo move this to constructor or init()
 }
 
 /* scan() strobes the row's strobePin and returns state of the shift register's input pins.
@@ -32,7 +32,7 @@ read_pins_t Scanner_ShiftRegsPISOMultiRow::scan(const uint8_t strobePin)
 {
     read_pins_t readState = 0;                  //bits, 1 means key is pressed, 0 means released
 
-    //SPI.beginTransaction( SPISettings(5000000, MSBFIRST, SPI_MODE0) ); //control SPI bus, 5 MHz
+    SPI.beginTransaction( SPISettings(5000000, MSBFIRST, SPI_MODE0) ); //control SPI bus, 5 MHz
 
     digitalWrite(slaveSelect, LOW);             //load parallel inputs to registers
 
@@ -46,7 +46,7 @@ read_pins_t Scanner_ShiftRegsPISOMultiRow::scan(const uint8_t strobePin)
 
     SPI.transfer(&readState, byte_count);
 
-    //SPI.endTransaction();
+    SPI.endTransaction();
 
     return readState;
 }