Base metal IR test program with sleep mode

Assumes factory default fuses (runs at 1Mhz).

/*

• SimpleIRTest.cpp
• This is the simplest possible IR test program.
• Is accesses the blink hardware directly with no interrupts and requires no library code (runs bare metal).
• It has three modes: TX, RX, and sleep
• TX mode
• =======
• Blink sends an IR pulse every 1ms on face IR0.
• The RGB LED on P0 shows green to indicate TX mode.
• Pushing button cycles though pulse transmitted pulse width.
• The pulse width is indicated by the number of BLUE LEDS lit:
• 1 blue = 5us
• 2 blue = 7us
• 3 blue = 10us
• 4 blue = 12us
• 5 blue = 15us
• The 'A' pin on the service port connector goes high while the IR LED is on.
• Pressing the button after the widest pulse width switches to RX mode
• RX mode
• =======
• Blink listens for an IR pulse on face IR0 every 2ms on face IR0.
• The RGB LED on face P0 shows RED to indicate RX.
• The time since the last trigger is indicated by which BLUE LEDS lit:
• P2 Cyan = <650us (Too short)
• P3 Blue = >650us and <950us (Just right)
• P4 Magenta = >950us (Too long)
• The 'A' pin on the service port connector pulses high when the IR0 LED is triggered. This pulse width is fixed and
• only indicates that a trigger happened.
• Pressing the button in RX mode goes to sleep mode
• SLEEP MODE
• ==========
• Blink goes into low power sleep.
• Pressing the button in sleep mode wakes the blink and goes to TX mode
• Usage
• =====
• You can cycle between modes and TX mode pulse times by pressing and releasing the button.
• Put one blink in TX mode and select a pulse width. Put another blink in RX mode. Aim their IR0 faces together.
• For the blink in RTX mode...
• P2 Cyan indicates that the IR LED is triggering by ambient light before the pulse arrives, or something is touching the LED
• P3 Blue indicates that pulses with expected timing are being received
• P4 Magenta in Rx mode indicates that some TX pulses are being missed
• Each of these indications will stay lit for about 0.1 second after the event so you can see it.
• If only P5 on RX lights then this is a good sign that good communication is possible.
• Connect an oscilloscope to the A pin on both blinks. Trigger on the A pin from the TX blink and watch to
• see how long it takes for the RX to trigger after the TX pulse is sent.
• Watch for the min and max of the timing between the RX and TX going high on pin A of the two blinks
• Short and consistent times are good.

*/