diff options
Diffstat (limited to '')
| -rw-r--r-- | hw/hank/vdivider-1634.h | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/hw/hank/vdivider-1634.h b/hw/hank/vdivider-1634.h new file mode 100644 index 0000000..171267d --- /dev/null +++ b/hw/hank/vdivider-1634.h @@ -0,0 +1,39 @@ +// attiny1634 voltage divider common defs +// Copyright (C) 2020-2023 Selene ToyKeeper +// SPDX-License-Identifier: GPL-3.0-or-later +#pragma once + +#define USE_VOLTAGE_DIVIDER // use a dedicated pin, not VCC, because VCC input is flattened +#define VOLTAGE_PIN PB1 // Pin 18 / PB1 / ADC6 +// pin to ADC mappings are in DS table 19-4 +#define VOLTAGE_ADC ADC6D // digital input disable pin for PB1 +// DIDR0/DIDR1 mappings are in DS section 19.13.5, 19.13.6 +#define VOLTAGE_ADC_DIDR DIDR1 // DIDR channel for ADC6D +// DS tables 19-3, 19-4 +// Bit 7 6 5 4 3 2 1 0 +// REFS1 REFS0 REFEN ADC0EN MUX3 MUX2 MUX1 MUX0 +// MUX[3:0] = 0, 1, 1, 0 for ADC6 / PB1 +// divided by ... +// REFS[1:0] = 1, 0 for internal 1.1V reference +// other bits reserved +#define ADMUX_VOLTAGE_DIVIDER 0b10000110 +#undef voltage_raw2cooked +#define voltage_raw2cooked mcu_vdivider_raw2cooked + +#define ADC_PRSCL 0x07 // clk/128 + +// 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) +// D1, R1, R2 = 0, 330, 100 +#ifndef ADC_44 +//#define ADC_44 (4*981) // raw value at 4.40V +#define ADC_44 (4*967) // manually tweaked so 4.16V will blink out 4.2 +#endif +#ifndef ADC_22 +//#define ADC_22 (4*489) // raw value at 2.20V +#define ADC_22 (4*482) // manually tweaked so 4.16V will blink out 4.2 +#endif + + |