From 4b22f60e516c3b4d647df7a88da4efc2af42cf36 Mon Sep 17 00:00:00 2001 From: Stephan Hadinger Date: Sun, 3 May 2020 10:39:38 +0200 Subject: [PATCH] Change PWM updated to latest Arduino Core #7213 --- tasmota/CHANGELOG.md | 1 + tasmota/core_esp8266_waveform.cpp | 445 ++++++++++++++++------------ tasmota/core_esp8266_wiring_pwm.cpp | 4 +- 3 files changed, 260 insertions(+), 190 deletions(-) diff --git a/tasmota/CHANGELOG.md b/tasmota/CHANGELOG.md index 8bdb07297..648dac861 100644 --- a/tasmota/CHANGELOG.md +++ b/tasmota/CHANGELOG.md @@ -3,6 +3,7 @@ ### 8.2.0.6 20200501 - Add experimental basic support for Tasmota on ESP32 based on work by Jörg Schüler-Maroldt +- Change PWM updated to latest Arduino Core #7213 ### 8.2.0.5 20200425 diff --git a/tasmota/core_esp8266_waveform.cpp b/tasmota/core_esp8266_waveform.cpp index 16bd7b40a..c39670686 100644 --- a/tasmota/core_esp8266_waveform.cpp +++ b/tasmota/core_esp8266_waveform.cpp @@ -5,23 +5,23 @@ Copyright (c) 2018 Earle F. Philhower, III. All rights reserved. The core idea is to have a programmable waveform generator with a unique - high and low period (defined in microseconds or CPU clock cycles). TIMER1 is - set to 1-shot mode and is always loaded with the time until the next edge - of any live waveforms. + high and low period (defined in microseconds or CPU clock cycles). TIMER1 + is set to 1-shot mode and is always loaded with the time until the next + edge of any live waveforms. Up to one waveform generator per pin supported. - Each waveform generator is synchronized to the ESP clock cycle counter, not the - timer. This allows for removing interrupt jitter and delay as the counter - always increments once per 80MHz clock. Changes to a waveform are + Each waveform generator is synchronized to the ESP clock cycle counter, not + the timer. This allows for removing interrupt jitter and delay as the + counter always increments once per 80MHz clock. Changes to a waveform are contiguous and only take effect on the next waveform transition, allowing for smooth transitions. This replaces older tone(), analogWrite(), and the Servo classes. Everywhere in the code where "cycles" is used, it means ESP.getCycleCount() - clock cycle count, or an interval measured in CPU clock cycles, but not TIMER1 - cycles (which may be 2 CPU clock cycles @ 160MHz). + clock cycle count, or an interval measured in CPU clock cycles, but not + TIMER1 cycles (which may be 2 CPU clock cycles @ 160MHz). This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public @@ -65,60 +65,62 @@ typedef struct { uint32_t expiryCycle; // For time-limited waveform, the cycle when this waveform must stop uint32_t timeHighCycles; // Currently running waveform period uint32_t timeLowCycles; // + uint32_t desiredHighCycles; // Currently running waveform period + uint32_t desiredLowCycles; // uint32_t gotoTimeHighCycles; // Copied over on the next period to preserve phase uint32_t gotoTimeLowCycles; // + uint32_t lastEdge; // } Waveform; -static Waveform waveform[17]; // State of all possible pins -static volatile uint32_t waveformState = 0; // Is the pin high or low, updated in NMI so no access outside the NMI code -static volatile uint32_t waveformEnabled = 0; // Is it actively running, updated in NMI so no access outside the NMI code +class WVFState { +public: + Waveform waveform[17]; // State of all possible pins + uint32_t waveformState = 0; // Is the pin high or low, updated in NMI so no access outside the NMI code + uint32_t waveformEnabled = 0; // Is it actively running, updated in NMI so no access outside the NMI code -// Enable lock-free by only allowing updates to waveformState and waveformEnabled from IRQ service routine -static volatile uint32_t waveformToEnable = 0; // Message to the NMI handler to start a waveform on a inactive pin -static volatile uint32_t waveformToDisable = 0; // Message to the NMI handler to disable a pin from waveform generation + // Enable lock-free by only allowing updates to waveformState and waveformEnabled from IRQ service routine + uint32_t waveformToEnable = 0; // Message to the NMI handler to start a waveform on a inactive pin + uint32_t waveformToDisable = 0; // Message to the NMI handler to disable a pin from waveform generation -volatile int32_t waveformToChange = -1; -volatile uint32_t waveformNewHigh = 0; -volatile uint32_t waveformNewLow = 0; + int32_t waveformToChange = -1; + uint32_t waveformNewHigh = 0; + uint32_t waveformNewLow = 0; -static uint32_t (*timer1CB)() = NULL; + uint32_t (*timer1CB)() = NULL; + + // Optimize the NMI inner loop by keeping track of the min and max GPIO that we + // are generating. In the common case (1 PWM) these may be the same pin and + // we can avoid looking at the other pins. + int startPin = 0; + int endPin = 0; +}; +static WVFState wvfState; + + +// Ensure everything is read/written to RAM +#define MEMBARRIER() { __asm__ volatile("" ::: "memory"); } // Non-speed critical bits #pragma GCC optimize ("Os") -static inline ICACHE_RAM_ATTR uint32_t GetCycleCount() { - uint32_t ccount; - __asm__ __volatile__("esync; rsr %0,ccount":"=a"(ccount)); - return ccount; -} - // Interrupt on/off control static ICACHE_RAM_ATTR void timer1Interrupt(); static bool timerRunning = false; static void initTimer() { - timer1_disable(); - ETS_FRC_TIMER1_INTR_ATTACH(NULL, NULL); - ETS_FRC_TIMER1_NMI_INTR_ATTACH(timer1Interrupt); - timer1_enable(TIM_DIV1, TIM_EDGE, TIM_SINGLE); - timerRunning = true; + if (!timerRunning) { + timer1_disable(); + ETS_FRC_TIMER1_INTR_ATTACH(NULL, NULL); + ETS_FRC_TIMER1_NMI_INTR_ATTACH(timer1Interrupt); + timer1_enable(TIM_DIV1, TIM_EDGE, TIM_SINGLE); + timerRunning = true; + timer1_write(microsecondsToClockCycles(10)); + } } -static void ICACHE_RAM_ATTR deinitTimer() { - ETS_FRC_TIMER1_NMI_INTR_ATTACH(NULL); - timer1_disable(); - timer1_isr_init(); - timerRunning = false; -} - -// Set a callback. Pass in NULL to stop it -void setTimer1Callback(uint32_t (*fn)()) { - timer1CB = fn; - if (!timerRunning && fn) { - initTimer(); - timer1_write(microsecondsToClockCycles(1)); // Cause an interrupt post-haste - } else if (timerRunning && !fn && !waveformEnabled) { - deinitTimer(); +static ICACHE_RAM_ATTR void forceTimerInterrupt() { + if (T1L > microsecondsToClockCycles(10)) { + T1L = microsecondsToClockCycles(10); } } @@ -135,24 +137,31 @@ void setTimer1Callback(uint32_t (*fn)()) { constexpr int maxPWMs = 8; -// PWM edge definition -typedef struct { - unsigned int pin : 8; - unsigned int delta : 24; -} PWMEntry; - // PWM machine state typedef struct { uint32_t mask; // Bitmask of active pins - uint8_t cnt; // How many entries - uint8_t idx; // Where the state machine is along the list - PWMEntry edge[maxPWMs + 1]; // Include space for terminal element + uint32_t cnt; // How many entries + uint32_t idx; // Where the state machine is along the list + uint8_t pin[maxPWMs + 1]; + uint32_t delta[maxPWMs + 1]; uint32_t nextServiceCycle; // Clock cycle for next step } PWMState; static PWMState pwmState; -static volatile PWMState *pwmUpdate = nullptr; // Set by main code, cleared by ISR -static uint32_t pwmPeriod = (1000000L * system_get_cpu_freq()) / 1000; +static PWMState *pwmUpdate = nullptr; // Set by main code, cleared by ISR +static uint32_t pwmPeriod = microsecondsToClockCycles(1000000UL) / 1000; + + + +static ICACHE_RAM_ATTR void disableIdleTimer() { + if (timerRunning && !wvfState.waveformEnabled && !pwmState.cnt && !wvfState.timer1CB) { + ETS_FRC_TIMER1_NMI_INTR_ATTACH(NULL); + timer1_disable(); + timer1_isr_init(); + timerRunning = false; + } +} + // Called when analogWriteFreq() changed to update the PWM total period void _setPWMPeriodCC(uint32_t cc) { @@ -168,111 +177,118 @@ void _setPWMPeriodCC(uint32_t cc) { PWMState p; // The working copy since we can't edit the one in use p = pwmState; uint32_t ttl = 0; - for (auto i = 0; i < p.cnt; i++) { - uint64_t val64p16 = ((uint64_t)p.edge[i].delta) << 16; + for (uint32_t i = 0; i < p.cnt; i++) { + uint64_t val64p16 = ((uint64_t)p.delta[i]) << 16; uint64_t newVal64p32 = val64p16 * ratio64p16; - p.edge[i].delta = newVal64p32 >> 32; - ttl += p.edge[i].delta; + p.delta[i] = newVal64p32 >> 32; + ttl += p.delta[i]; } - p.edge[p.cnt].delta = cc - ttl; // Final cleanup exactly cc total cycles + p.delta[p.cnt] = cc - ttl; // Final cleanup exactly cc total cycles // Update and wait for mailbox to be emptied pwmUpdate = &p; + MEMBARRIER(); + forceTimerInterrupt(); while (pwmUpdate) { delay(0); + // No mem barrier. The external function call guarantees it's re-read } } pwmPeriod = cc; } // Helper routine to remove an entry from the state machine -static void _removePWMEntry(int pin, PWMState *p) { - if (!((1<mask)) { - return; - } +static ICACHE_RAM_ATTR void _removePWMEntry(int pin, PWMState *p) { + uint32_t i; + + // Find the pin to pull out... + for (i = 0; p->pin[i] != pin; i++) { /* no-op */ } + auto delta = p->delta[i]; - int delta = 0; - int i; - for (i=0; i < p->cnt; i++) { - if (p->edge[i].pin == pin) { - delta = p->edge[i].delta; - break; - } - } // Add the removed previous pin delta to preserve absolute position - p->edge[i+1].delta += delta; - // Move everything back one and clean up + p->delta[i+1] += delta; + + // Move everything back one for (i++; i <= p->cnt; i++) { - p->edge[i-1] = p->edge[i]; + p->pin[i-1] = p->pin[i]; + p->delta[i-1] = p->delta[i]; } + // Remove the pin from the active list p->mask &= ~(1<cnt--; } // Called by analogWrite(0/100%) to disable PWM on a specific pin -bool _stopPWM(int pin) { +ICACHE_RAM_ATTR bool _stopPWM(int pin) { if (!((1<= maxPWMs) { return false; // No space left } else if (p.cnt == 0) { // Starting up from scratch, special case 1st element and PWM period - p.edge[0].pin = pin; - p.edge[0].delta = cc; - p.edge[1].pin = 0xff; - p.edge[1].delta = pwmPeriod - cc; + p.pin[0] = pin; + p.delta[0] = cc; + p.pin[1] = 0xff; + p.delta[1] = pwmPeriod - cc; p.cnt = 1; p.mask = 1<high transition. For immediate change, stopWaveform() // first, then it will immediately begin. @@ -284,44 +300,59 @@ int startWaveformClockCycles(uint8_t pin, uint32_t timeHighCycles, uint32_t time if ((pin > 16) || isFlashInterfacePin(pin)) { return false; } - Waveform *wave = &waveform[pin]; - wave->expiryCycle = runTimeCycles ? GetCycleCount() + runTimeCycles : 0; + Waveform *wave = &wvfState.waveform[pin]; + wave->expiryCycle = runTimeCycles ? ESP.getCycleCount() + runTimeCycles : 0; if (runTimeCycles && !wave->expiryCycle) { wave->expiryCycle = 1; // expiryCycle==0 means no timeout, so avoid setting it } + _stopPWM(pin); // Make sure there's no PWM live here + uint32_t mask = 1<= 0) { + MEMBARRIER(); + if (wvfState.waveformEnabled & mask) { + wvfState.waveformNewHigh = timeHighCycles; + wvfState.waveformNewLow = timeLowCycles; + MEMBARRIER(); + wvfState.waveformToChange = pin; + while (wvfState.waveformToChange >= 0) { delay(0); // Wait for waveform to update + // No mem barrier here, the call to a global function implies global state updated } - } else { // if (!(waveformEnabled & mask)) { + } else { // if (!(wvfState.waveformEnabled & mask)) { wave->timeHighCycles = timeHighCycles; wave->timeLowCycles = timeLowCycles; + wave->desiredHighCycles = wave->timeHighCycles; + wave->desiredLowCycles = wave->timeLowCycles; + wave->lastEdge = 0; wave->gotoTimeHighCycles = wave->timeHighCycles; wave->gotoTimeLowCycles = wave->timeLowCycles; // Actually set the pin high or low in the IRQ service to guarantee times - wave->nextServiceCycle = GetCycleCount() + microsecondsToClockCycles(1); - waveformToEnable |= mask; - if (!timerRunning) { - initTimer(); - timer1_write(microsecondsToClockCycles(10)); - } else { - // Ensure timely service.... - if (T1L > microsecondsToClockCycles(10)) { - timer1_write(microsecondsToClockCycles(10)); - } - } - while (waveformToEnable) { + wave->nextServiceCycle = ESP.getCycleCount() + microsecondsToClockCycles(1); + wvfState.waveformToEnable |= mask; + MEMBARRIER(); + initTimer(); + forceTimerInterrupt(); + while (wvfState.waveformToEnable) { delay(0); // Wait for waveform to update + // No mem barrier here, the call to a global function implies global state updated } } return true; } + +// Set a callback. Pass in NULL to stop it +void setTimer1Callback(uint32_t (*fn)()) { + wvfState.timer1CB = fn; + if (fn) { + initTimer(); + forceTimerInterrupt(); + } + disableIdleTimer(); +} + + // Speed critical bits #pragma GCC optimize ("O2") // Normally would not want two copies like this, but due to different @@ -349,76 +380,87 @@ int ICACHE_RAM_ATTR stopWaveform(uint8_t pin) { } // If user sends in a pin >16 but <32, this will always point to a 0 bit // If they send >=32, then the shift will result in 0 and it will also return false - uint32_t mask = 1< microsecondsToClockCycles(10)) { - timer1_write(microsecondsToClockCycles(10)); - } - while (waveformToDisable) { - /* no-op */ // Can't delay() since stopWaveform may be called from an IRQ - } - if (!waveformEnabled && !pwmState.cnt && !timer1CB) { - deinitTimer(); + if (wvfState.waveformEnabled & (1UL << pin)) { + wvfState.waveformToDisable = 1UL << pin; + forceTimerInterrupt(); + while (wvfState.waveformToDisable) { + MEMBARRIER(); // If it wasn't written yet, it has to be by now + /* no-op */ // Can't delay() since stopWaveform may be called from an IRQ + } } + disableIdleTimer(); return true; } // The SDK and hardware take some time to actually get to our NMI code, so // decrement the next IRQ's timer value by a bit so we can actually catch the // real CPU cycle counter we want for the waveforms. + +// The SDK also sometimes is running at a different speed the the Arduino core +// so the ESP cycle counter is actually running at a variable speed. +// adjust(x) takes care of adjusting a delta clock cycle amount accordingly. #if F_CPU == 80000000 #define DELTAIRQ (microsecondsToClockCycles(3)) + #define adjust(x) ((x) << (turbo ? 1 : 0)) #else #define DELTAIRQ (microsecondsToClockCycles(2)) + #define adjust(x) ((x) >> (turbo ? 0 : 1)) +#endif + +#define ENABLE_ADJUST // Adjust takes 36 bytes +#define ENABLE_FEEDBACK // Feedback costs 68 bytes +#define ENABLE_PWM // PWM takes 160 bytes + +#ifndef ENABLE_ADJUST + #undef adjust + #define adjust(x) (x) #endif static ICACHE_RAM_ATTR void timer1Interrupt() { - // Optimize the NMI inner loop by keeping track of the min and max GPIO that we - // are generating. In the common case (1 PWM) these may be the same pin and - // we can avoid looking at the other pins. - static int startPin = 0; - static int endPin = 0; + // Flag if the core is at 160 MHz, for use by adjust() + bool turbo = (*(uint32_t*)0x3FF00014) & 1 ? true : false; uint32_t nextEventCycles = microsecondsToClockCycles(MAXIRQUS); uint32_t timeoutCycle = GetCycleCountIRQ() + microsecondsToClockCycles(14); - if (waveformToEnable || waveformToDisable) { + if (wvfState.waveformToEnable || wvfState.waveformToDisable) { // Handle enable/disable requests from main app - waveformEnabled = (waveformEnabled & ~waveformToDisable) | waveformToEnable; // Set the requested waveforms on/off - waveformState &= ~waveformToEnable; // And clear the state of any just started - waveformToEnable = 0; - waveformToDisable = 0; + wvfState.waveformEnabled = (wvfState.waveformEnabled & ~wvfState.waveformToDisable) | wvfState.waveformToEnable; // Set the requested waveforms on/off + wvfState.waveformState &= ~wvfState.waveformToEnable; // And clear the state of any just started + wvfState.waveformToEnable = 0; + wvfState.waveformToDisable = 0; + // No mem barrier. Globals must be written to RAM on ISR exit. // Find the first GPIO being generated by checking GCC's find-first-set (returns 1 + the bit of the first 1 in an int32_t) - startPin = __builtin_ffs(waveformEnabled) - 1; + wvfState.startPin = __builtin_ffs(wvfState.waveformEnabled) - 1; // Find the last bit by subtracting off GCC's count-leading-zeros (no offset in this one) - endPin = 32 - __builtin_clz(waveformEnabled); + wvfState.endPin = 32 - __builtin_clz(wvfState.waveformEnabled); +#ifdef ENABLE_PWM } else if (!pwmState.cnt && pwmUpdate) { // Start up the PWM generator by copying from the mailbox - pwmState = *(PWMState*)pwmUpdate; - pwmUpdate = nullptr; + pwmState.cnt = 1; + pwmState.idx = 1; // Ensure copy this cycle, cause it to start at t=0 pwmState.nextServiceCycle = GetCycleCountIRQ(); // Do it this loop! - pwmState.idx = pwmState.cnt; // Cause it to start at t=0 - } else if (waveformToChange >=0) { - waveform[waveformToChange].gotoTimeHighCycles = waveformNewHigh; - waveform[waveformToChange].gotoTimeLowCycles = waveformNewLow; - waveformToChange = -1; + // No need for mem barrier here. Global must be written by IRQ exit +#endif + } else if (wvfState.waveformToChange >= 0) { + wvfState.waveform[wvfState.waveformToChange].gotoTimeHighCycles = wvfState.waveformNewHigh; + wvfState.waveform[wvfState.waveformToChange].gotoTimeLowCycles = wvfState.waveformNewLow; + wvfState.waveformToChange = -1; + // No need for memory barrier here. The global has to be written before exit the ISR. } bool done = false; - if (waveformEnabled || pwmState.cnt) { + if (wvfState.waveformEnabled || pwmState.cnt) { do { nextEventCycles = microsecondsToClockCycles(MAXIRQUS); - + +#ifdef ENABLE_PWM // PWM state machine implementation if (pwmState.cnt) { - uint32_t now = GetCycleCountIRQ(); + uint32_t now = GetCycleCountIRQ(); int32_t cyclesToGo = pwmState.nextServiceCycle - now; - if (cyclesToGo <= 10) { + if (cyclesToGo < 0) { if (pwmState.idx == pwmState.cnt) { // Start of pulses, possibly copy new if (pwmUpdate) { // Do the memory copy from temp to global and clear mailbox @@ -427,39 +469,39 @@ static ICACHE_RAM_ATTR void timer1Interrupt() { } GPOS = pwmState.mask; // Set all active pins high // GPIO16 isn't the same as the others - if (pwmState.mask & 0x100) { - GP16O |= 1; + if (pwmState.mask & (1<<16)) { + GP16O = 1; } pwmState.idx = 0; } else { do { // Drop the pin at this edge - GPOC = 1<expiryCycle - now; if (expiryToGo < 0) { // Done, remove! - waveformEnabled &= ~mask; + wvfState.waveformEnabled &= ~mask; if (i == 16) { - GP16O &= ~1; + GP16O = 0; } else { ClearGPIO(mask); } @@ -480,27 +522,58 @@ static ICACHE_RAM_ATTR void timer1Interrupt() { // Check for toggles int32_t cyclesToGo = wave->nextServiceCycle - now; if (cyclesToGo < 0) { - waveformState ^= mask; - if (waveformState & mask) { + uint32_t nextEdgeCycles; + uint32_t desired = 0; + uint32_t *timeToUpdate; + wvfState.waveformState ^= mask; + if (wvfState.waveformState & mask) { if (i == 16) { - GP16O |= 1; // GPIO16 write slow as it's RMW + GP16O = 1; // GPIO16 write slow as it's RMW } else { SetGPIO(mask); } - wave->nextServiceCycle = now + wave->timeHighCycles; - nextEventCycles = min_u32(nextEventCycles, wave->timeHighCycles); + if (wave->gotoTimeHighCycles) { + // Copy over next full-cycle timings + wave->timeHighCycles = wave->gotoTimeHighCycles; + wave->desiredHighCycles = wave->gotoTimeHighCycles; + wave->timeLowCycles = wave->gotoTimeLowCycles; + wave->desiredLowCycles = wave->gotoTimeLowCycles; + wave->gotoTimeHighCycles = 0; + } else { +#ifdef ENABLE_FEEDBACK + if (wave->lastEdge) { + desired = wave->desiredLowCycles; + timeToUpdate = &wave->timeLowCycles; + } + } +#endif + nextEdgeCycles = wave->timeHighCycles; } else { if (i == 16) { - GP16O &= ~1; // GPIO16 write slow as it's RMW + GP16O = 0; // GPIO16 write slow as it's RMW } else { ClearGPIO(mask); } - wave->nextServiceCycle = now + wave->timeLowCycles; - nextEventCycles = min_u32(nextEventCycles, wave->timeLowCycles); - // Copy over next full-cycle timings - wave->timeHighCycles = wave->gotoTimeHighCycles; - wave->timeLowCycles = wave->gotoTimeLowCycles; +#ifdef ENABLE_FEEDBACK + desired = wave->desiredHighCycles; + timeToUpdate = &wave->timeHighCycles; +#endif + nextEdgeCycles = wave->timeLowCycles; } +#ifdef ENABLE_FEEDBACK + if (desired) { + desired = adjust(desired); + int32_t err = desired - (now - wave->lastEdge); + if (abs(err) < desired) { // If we've lost > the entire phase, ignore this error signal + err /= 2; + *timeToUpdate += err; + } + } +#endif + nextEdgeCycles = adjust(nextEdgeCycles); + wave->nextServiceCycle = now + nextEdgeCycles; + nextEventCycles = min_u32(nextEventCycles, nextEdgeCycles); + wave->lastEdge = now; } else { uint32_t deltaCycles = wave->nextServiceCycle - now; nextEventCycles = min_u32(nextEventCycles, deltaCycles); @@ -513,10 +586,10 @@ static ICACHE_RAM_ATTR void timer1Interrupt() { int32_t cyclesLeftTimeout = timeoutCycle - now; done = (cycleDeltaNextEvent < 0) || (cyclesLeftTimeout < 0); } while (!done); - } // if (waveformEnabled) + } // if (wvfState.waveformEnabled) - if (timer1CB) { - nextEventCycles = min_u32(nextEventCycles, timer1CB()); + if (wvfState.timer1CB) { + nextEventCycles = min_u32(nextEventCycles, wvfState.timer1CB()); } if (nextEventCycles < microsecondsToClockCycles(5)) { @@ -525,11 +598,7 @@ static ICACHE_RAM_ATTR void timer1Interrupt() { nextEventCycles -= DELTAIRQ; // Do it here instead of global function to save time and because we know it's edge-IRQ -#if F_CPU == 160000000 - T1L = nextEventCycles >> 1; // Already know we're in range by MAXIRQUS -#else - T1L = nextEventCycles; // Already know we're in range by MAXIRQUS -#endif + T1L = nextEventCycles >> (turbo ? 1 : 0); TEIE |= TEIE1; // Edge int enable } diff --git a/tasmota/core_esp8266_wiring_pwm.cpp b/tasmota/core_esp8266_wiring_pwm.cpp index ec76b007b..90d69b313 100644 --- a/tasmota/core_esp8266_wiring_pwm.cpp +++ b/tasmota/core_esp8266_wiring_pwm.cpp @@ -47,8 +47,8 @@ extern void __analogWriteRange(uint32_t range) { extern void __analogWriteFreq(uint32_t freq) { if (freq < 100) { analogFreq = 100; - } else if (freq > 40000) { - analogFreq = 40000; + } else if (freq > 60000) { + analogFreq = 60000; } else { analogFreq = freq; }