TELEMETRY_MOD=14051 (by gerardv @ forum.turnigy9xr.com) makes USART0 available
by reallocating AIL and THR onto pins 14 and 15 of the 14051 multiplexer.
TELEMETRY_MOD=14051_SWAPPED is based on TELEMETRY_MOD=14051, but uses USART1
instead of USART0, freeing USART0 for other purposes (debugging, interfacing
via AVRISP port). USART1 is freed up by reallocating LVert Trim Dn/Up onto
14051's 12 and 1 pins respectively.
Additionally, this commit cleans a few things up:
* moves AVR ADC-related code to adc_driver.cpp,
* provides #defines to have a convenient way to access either USART0 or USART1
registers depending on static (build-time) configuration
* moves code related to this telemetry mod to board_stock
* replaces a few magic numbers with enums.
Thanks to Bernard Songis for review and suggestions!
The functionality of timer0 and timer2 are switched between ATmega64/128
and 641/1281/2561. When compiled for ATmega2561, this commit sets up timer0
in the same way as timer2 on ATmega64/128 (phase correct PWM, clk/64 count
rate, inverted if SP22 is defined).
The previous quick fix had a typo in the initialization of TCCR0B (0b111 is
an invalid value for the clock select bits CS2:0). It also did not respect
the SP22 define which indicates the PWM must be inverted. Smartieparts
v2.2 or later programmer boards have an inverted backlight driver. Finally,
it is unnecessary to set DDB7 as it is already set in boardInit() (line
101).
Bertrand Songis