diff --git a/lib/LinkIR.cpp b/lib/LinkIR.cpp
index f362a45..31ecafd 100644
--- a/lib/LinkIR.cpp
+++ b/lib/LinkIR.cpp
@@ -4,21 +4,18 @@
 //   38kHz signal => 38000/second =>
 //     period = 1000000µs / 38000 = 26.31µs
 //     halfPeriod = 13.15µs
-// LED ON  => RCNT = 0x8098 (GPIO mode, SC and SO as OUTPUT, SO=HIGH)
-// LED OFF => RCNT = 0x8090 (GPIO mode, SC and SO as OUTPUT, SO=LOW)
+// LED ON  => RCNT = 0x80BA (GPIO mode, SC, SD, SO as OUTPUT, SD=HIGH, SO=HIGH)
+// LED OFF => RCNT = 0x80B2 (GPIO mode, SC, SD,  SO as OUTPUT, SD=HIGH, SO=LOW)
 
 LINK_CODE_IWRAM void LinkIR::generate38kHzSignal(u32 microseconds) {
   // halfPeriods = ceil(microseconds / 13.15 µs) (in fixed-point math)
-  u32 halfPeriods = (microseconds * 100 + 1315) / 1316;
-  // force an odd count so the final value will be 0x8090 (LED OFF)
-  if ((halfPeriods & 1) == 0)
-    halfPeriods++;
+  u32 halfPeriods = Link::_max((microseconds * 100 + 1315) / 1316, 1);
 
   // the GBA is 16.776MHz => 13.15 µs ~= 220 cycles per half-period
 
   asm volatile(
       "mov    r0, %0          \n"  // r0 = address of REG_RCNT
-      "ldr    r1, =0x8098     \n"  // r1 = initial value 0x8098 (LED ON)
+      "ldr    r1, =0x80BA     \n"  // r1 = initial value 0x80BA (LED ON)
       "mov    r2, %1          \n"  // r2 = main loop count (halfPeriods)
       "1:                     \n"  // --- main loop ---
       "strh   r1, [r0]        \n"  // write current value to REG_RCNT
@@ -32,11 +29,11 @@ LINK_CODE_IWRAM void LinkIR::generate38kHzSignal(u32 microseconds) {
       //     [first 53 iterations (branch taken): 53 * ~4 cycles = ~212 cycles]
       //     [final iteration (branch not taken): ~2 cycles]
       //     [overhead: ~6 cycles]
-      "eor    r1, r1, #8      \n"  // toggle r1: 0x8098^8 = 0x8090 (& viceversa)
+      "eor    r1, r1, #8      \n"  // toggle r1: 0x80BA^8 = 0x80B2 (& viceversa)
       "subs   r2, r2, #1      \n"  // decrement main loop count
       "bne    1b              \n"  // repeat main loop if needed
-      "ldr    r1, =0x8090     \n"  // ensure we end with 0x8090
-      "strh   r1, [r0]        \n"  // write REG_RCNT = 0x8090 (LED OFF)
+      "ldr    r1, =0x80B2     \n"  // ensure we end with 0x80B2
+      "strh   r1, [r0]        \n"  // write REG_RCNT = 0x80B2 (LED OFF)
       :
       : "r"(&Link::_REG_RCNT), "r"(halfPeriods)
       : "r0", "r1", "r2", "r3");
diff --git a/lib/LinkIR.hpp b/lib/LinkIR.hpp
index ba491ac..40daea6 100644
--- a/lib/LinkIR.hpp
+++ b/lib/LinkIR.hpp
@@ -103,6 +103,8 @@ class LinkIR {
 
     linkGPIO.setMode(Pin::SC, Direction::OUTPUT);
     linkGPIO.writePin(Pin::SC, false);
+    linkGPIO.setMode(Pin::SD, Direction::OUTPUT);
+    linkGPIO.writePin(Pin::SD, true);
     linkGPIO.setMode(Pin::SO, Direction::OUTPUT);
     linkGPIO.writePin(Pin::SO, false);
     linkGPIO.setSIInterrupts(true);
@@ -166,10 +168,12 @@ class LinkIR {
 
   bool receiveNEC(u8& address, u8& command) {
     // TODO: IMPLEMENT
+    return false;
   }
 
   bool receive(u16 pulses[], u32 maxEntries, u32 timeout) {
     // TODO: IMPLEMENT
+    return false;
   }
 
   /**