diff options
Diffstat (limited to 'arch/attiny1616.c')
| -rw-r--r-- | arch/attiny1616.c | 125 |
1 files changed, 100 insertions, 25 deletions
diff --git a/arch/attiny1616.c b/arch/attiny1616.c index a3ead7e..330c809 100644 --- a/arch/attiny1616.c +++ b/arch/attiny1616.c @@ -7,36 +7,60 @@ ////////// clock speed / delay stuff ////////// +inline void mcu_clock_speed() { + // TODO: allow hwdef to define a base clock speed + // set up the system clock to run at 10 MHz instead of the default 3.33 MHz + _PROTECTED_WRITE( CLKCTRL.MCLKCTRLB, + CLKCTRL_PDIV_2X_gc | CLKCTRL_PEN_bm ); +} + ///// clock dividers // this should work, but needs further validation inline void clock_prescale_set(uint8_t n) { cli(); - CCP = CCP_IOREG_gc; // temporarily disable clock change protection - CLKCTRL.MCLKCTRLB = n; // Set the prescaler + _PROTECTED_WRITE(CLKCTRL.MCLKCTRLB, n); // Set the prescaler while (CLKCTRL.MCLKSTATUS & CLKCTRL_SOSC_bm) {} // wait for clock change to finish sei(); } + ////////// ADC voltage / temperature ////////// inline void mcu_set_admux_therm() { + // put the ADC in temperature mode + // attiny1616 datasheet section 30.3.2.6 + VREF.CTRLA = (VREF.CTRLA & (~VREF_ADC0REFSEL_gm)) + | VREF_ADC0REFSEL_1V1_gc; // Set Vbg ref to 1.1V ADC0.MUXPOS = ADC_MUXPOS_TEMPSENSE_gc; // read temperature + ADC0.CTRLB = ADC_SAMPNUM_ACC4_gc; // 10-bit result + 4x oversampling ADC0.CTRLC = ADC_SAMPCAP_bm - | ADC_PRESC_DIV64_gc + | ADC_PRESC_DIV16_gc | ADC_REFSEL_INTREF_gc; // Internal ADC reference } inline void mcu_set_admux_voltage() { - #ifdef USE_VOLTAGE_DIVIDER // 1.1V / ADC input pin - // verify that this is correct!!! untested + // Enabled, free-running (aka, auto-retrigger), run in standby + ADC0.CTRLA = ADC_ENABLE_bm | ADC_FREERUN_bm | ADC_RUNSTBY_bm; + // set a INITDLY value because the AVR manual says so (section 30.3.5) + // (delay 1st reading until Vref is stable) + ADC0.CTRLD |= ADC_INITDLY_DLY16_gc; + #ifdef USE_VOLTAGE_DIVIDER // measure an arbitrary pin + // result = resolution * Vdiv / 1.1V + VREF.CTRLA = (VREF.CTRLA & (~VREF_ADC0REFSEL_gm)) + | VREF_ADC0REFSEL_1V1_gc; // Set Vbg ref to 1.1V ADC0.MUXPOS = ADMUX_VOLTAGE_DIVIDER; // read the requested ADC pin + ADC0.CTRLB = ADC_SAMPNUM_ACC4_gc; // 12-bit result, 4x oversampling ADC0.CTRLC = ADC_SAMPCAP_bm - | ADC_PRESC_DIV64_gc + | ADC_PRESC_DIV16_gc | ADC_REFSEL_INTREF_gc; // Use internal ADC reference - #else // VCC / 1.1V reference + #else // measure VDD pin + // result = resolution * 1.5V / Vbat + VREF.CTRLA = (VREF.CTRLA & (~VREF_ADC0REFSEL_gm)) + | VREF_ADC0REFSEL_1V5_gc; // Set Vbg ref to 1.5V ADC0.MUXPOS = ADC_MUXPOS_INTREF_gc; // read internal reference + ADC0.CTRLB = ADC_SAMPNUM_ACC4_gc; // 12-bit result, 4x oversampling ADC0.CTRLC = ADC_SAMPCAP_bm - | ADC_PRESC_DIV64_gc + | ADC_PRESC_DIV16_gc | ADC_REFSEL_VDDREF_gc; // Vdd (Vcc) be ADC reference #endif } @@ -47,9 +71,10 @@ inline void mcu_adc_sleep_mode() { inline void mcu_adc_start_measurement() { ADC0.INTCTRL |= ADC_RESRDY_bm; // enable interrupt - ADC0.COMMAND |= ADC_STCONV_bm; // Start the ADC conversions + ADC0.COMMAND |= ADC_STCONV_bm; // actually start measuring } +/* inline void mcu_adc_on() { VREF.CTRLA |= VREF_ADC0REFSEL_1V1_gc; // Set Vbg ref to 1.1V // Enabled, free-running (aka, auto-retrigger), run in standby @@ -59,6 +84,7 @@ inline void mcu_adc_on() { ADC0.CTRLD |= ADC_INITDLY_DLY16_gc; hwdef_set_admux_voltage(); } +*/ inline void mcu_adc_off() { ADC0.CTRLA &= ~(ADC_ENABLE_bm); // disable the ADC @@ -69,22 +95,69 @@ inline void mcu_adc_vect_clear() { } inline uint16_t mcu_adc_result_temp() { - // Use the factory calibrated values in SIGROW.TEMPSENSE0 and - // SIGROW.TEMPSENSE1 to calculate a temperature reading in Kelvin, then - // left-align it. - int8_t sigrow_offset = SIGROW.TEMPSENSE1; // Read signed value from signature row - uint8_t sigrow_gain = SIGROW.TEMPSENSE0; // Read unsigned value from signature row - uint32_t temp = ADC0.RES - sigrow_offset; - temp *= sigrow_gain; // Result might overflow 16 bit variable (10bit+8bit) - temp += 0x80; // Add 1/2 to get correct rounding on division below - //temp >>= 8; // Divide result to get Kelvin - //return temp << 6; // left align it - return temp >> 2; // left-aligned uint16_t + // just return left-aligned ADC result, don't convert to calibrated units + //return ADC0.RES << 6; + return ADC0.RES << 4; } inline uint16_t mcu_adc_result_volts() { - // FIXME: set up ADC to use left-aligned values natively - return ADC0.RES << 6; // voltage, force left-alignment + // ADC has no left-aligned mode, so left-align it manually + return ADC0.RES << 4; +} + +inline uint8_t mcu_vdd_raw2cooked(uint16_t measurement) { + // In : 65535 * 1.5 / Vbat + // Out: uint8_t: Vbat * 40 + // 1.5 = ADC Vref + #if 0 + // 1024 = how much ADC resolution we're using (10 bits) + // (12 bits available, but it costs an extra 84 bytes of ROM to calculate) + uint8_t vbat40 = (uint16_t)(40 * 1.5 * 1024) / (measurement >> 6); + #else + // ... spend the extra 84 bytes of ROM for better precision + // 4096 = how much ADC resolution we're using (12 bits) + uint8_t vbat40 = (uint32_t)(40 * 1.5 * 4096) / (measurement >> 4); + #endif + return vbat40; +} + +#if 0 // fine voltage, 0 to 10.24V in 1/6400th V steps +inline uint16_t mcu_vdd_raw2fine(uint16_t measurement) { + // In : 65535 * 1.5 / Vbat + // Out: 65535 * (Vbat / 10) / 1.024V + uint16_t voltage = ((uint32_t)(1.5 * 4096 * 100 * 64 * 16) / measurement; + return voltage; +} +#endif + +#ifdef USE_VOLTAGE_DIVIDER +inline uint8_t mcu_vdivider_raw2cooked(uint16_t measurement) { + // In : 4095 * Vdiv / 1.1V + // Out: uint8_t: Vbat * 40 + // Vdiv = Vbat / 4.3 (typically) + // 1.1 = ADC Vref + const uint16_t adc_per_volt = + (((uint16_t)ADC_44 << 4) - ((uint16_t)ADC_22 << 4)) + / (4 * (44-22)); + uint8_t result = measurement / adc_per_volt; + return result; +} +#endif + +inline uint16_t mcu_temp_raw2cooked(uint16_t measurement) { + // convert raw ADC values to calibrated temperature + // In: ADC raw temperature (16-bit, or 12-bit left-aligned) + // Out: Kelvin << 6 + // Precision: 1/64th Kelvin (but noisy) + // attiny1616 datasheet section 30.3.2.6 + uint8_t sigrow_gain = SIGROW.TEMPSENSE0; // factory calibration data + int8_t sigrow_offset = SIGROW.TEMPSENSE1; + const uint32_t scaling_factor = 65536; // use all 16 bits of ADC data + uint32_t temp = measurement - (sigrow_offset << 6); + temp *= sigrow_gain; // 24-bit result + temp += scaling_factor / 8; // Add 1/8th K to get correct rounding on later divisions + temp = temp >> 8; // change (K << 14) to (K << 6) + return temp; // left-aligned uint16_t, 0 to 1023.98 Kelvin } inline uint8_t mcu_adc_lsb() { @@ -98,13 +171,15 @@ inline uint8_t mcu_adc_lsb() { inline void mcu_wdt_active() { RTC.PITINTCTRL = RTC_PI_bm; // enable the Periodic Interrupt while (RTC.PITSTATUS > 0) {} // make sure the register is ready to be updated - RTC.PITCTRLA = RTC_PERIOD_CYC512_gc | RTC_PITEN_bm; // Period = 16ms, enable the PI Timer + // Period = 16ms (64 Hz), enable the PI Timer + RTC.PITCTRLA = RTC_PERIOD_CYC512_gc | RTC_PITEN_bm; } inline void mcu_wdt_standby() { RTC.PITINTCTRL = RTC_PI_bm; // enable the Periodic Interrupt while (RTC.PITSTATUS > 0) {} // make sure the register is ready to be updated - RTC.PITCTRLA = (1<<6) | (STANDBY_TICK_SPEED<<3) | RTC_PITEN_bm; // Set period, enable the PI Timer + // Set period (64 Hz / STANDBY_TICK_SPEED = 8 Hz), enable the PI Timer + RTC.PITCTRLA = (1<<6) | (STANDBY_TICK_SPEED<<3) | RTC_PITEN_bm; } inline void mcu_wdt_stop() { @@ -148,6 +223,6 @@ void reboot() { inline void prevent_reboot_loop() { // prevent WDT from rebooting MCU again RSTCTRL.RSTFR &= ~(RSTCTRL_WDRF_bm); // reset status flag - wdt_disable(); + wdt_disable(); // from avr/wdt.h } |