ADC voltage: battcheck 3 digits, fixed t1616, switched back to 8-bit internal volt unit

Before this branch, `voltage` was 6 bits: Volts * 10
A couple patches ago, I upgraded it to 16 bits: 65535 * Volts / 10.24
That costs too much extra ROM on attiny85 though, for extra precision
it doesn't even use... so I switched back to an 8-bit value.  It's still
more precise than before though: Volts * 40
... and battcheck displays an extra digit now, on devices with ROM for it.
... and battcheck waits a second to get a more accurate measurement
    before displaying the first value.  It has *much* less variation
    between first and later readings now.

Also:
- got t1616 builds working again (tested fc13 and thefreeman-boost-fwaa)
- upgraded t1616 voltage and temp to 12-bit (10 bits + 4x oversampling)
- removed expensive temp conversion from t1616 ADC interrupt
- recalibrated t1616 bogomips again; runs faster after interrupt fix
- increased t1616 internal VDD measurement resolution by 36% (1.5V Vref, not 1.1V)
- fixed sloppy setting of Vref bits

I still need to test / update other t1616 builds,
and fix all the t85 + t1634 code and build targets.

1 files changed, 8 insertions, 9 deletions

diff --git a/hw/thefreeman/boost-fwaa-mp3432-hdr-dac-rgb/hwdef.h b/hw/thefreeman/boost-fwaa-mp3432-hdr-dac-rgb/hwdef.h
index 095aea0..45c02de 100644
--- a/hw/thefreeman/boost-fwaa-mp3432-hdr-dac-rgb/hwdef.h
+++ b/hw/thefreeman/boost-fwaa-mp3432-hdr-dac-rgb/hwdef.h
@@ -103,21 +103,20 @@ enum CHANNEL_MODES {
 
 // Voltage divider battLVL
 #define USE_VOLTAGE_DIVIDER       // use a dedicated pin, not VCC, because VCC input is regulated
-#define DUAL_VOLTAGE_FLOOR     21 // for AA/14500 boost drivers, don't indicate low voltage if below this level
-#define DUAL_VOLTAGE_LOW_LOW   7  // the lower voltage range's danger zone 0.7 volts (NiMH)
+#define DUAL_VOLTAGE_FLOOR     (4*21) // for AA/14500 boost drivers, don't indicate low voltage if below this level
+#define DUAL_VOLTAGE_LOW_LOW   (4*7)  // the lower voltage range's danger zone 0.7 volts (NiMH)
 #define ADMUX_VOLTAGE_DIVIDER  ADC_MUXPOS_AIN2_gc  // which ADC channel to read
+#undef voltage_raw2cooked
+#define voltage_raw2cooked  mcu_vdivider_raw2cooked
+
 
 // Raw ADC readings at 4.4V and 2.2V
 // calibrate the voltage readout here
 // estimated / calculated values are:
-//   (voltage - D1) * (R2/(R2+R1) * 1024 / 1.1)
+//   (voltage - D1) * (R2/(R2+R1) * 4096 / 1.1)
 // Resistors are 330k and 100k
-#ifndef ADC_44
-#define ADC_44 951  // raw value at 4.40V
-#endif
-#ifndef ADC_22
-#define ADC_22 476  // raw value at 2.20V
-#endif
+#define ADC_44  3810  // raw value at 4.40V
+#define ADC_22  1905  // raw value at 2.20V
 
 // this driver allows for aux LEDs under the optic
 #define AUXLED_R_PIN  PIN3_bp