- Important Change from v1.2.0
- Why do we need this megaAVR_Slow_PWM library
- Changelog
- Prerequisites
- Installation
- HOWTO Fix
Multiple Definitions
Linker Error - More useful Information
- Usage
- Examples
- Example ISR_8_PWMs_Array_Complex
- Debug Terminal Output Samples
- Debug
- Troubleshooting
- Issues
- TO DO
- DONE
- Contributions and Thanks
- Contributing
- License
- Copyright
Please have a look at HOWTO Fix Multiple Definitions
Linker Error
As more complex calculation and check inside ISR are introduced from v1.2.0, there is possibly some crash depending on use-case.
You can modify to use larger HW_TIMER_INTERVAL_US
, (from current 33.3uS), according to your board and use-case if crash happens.
// Don't change these numbers to make higher Timer freq. System can hang
#define HW_TIMER_INTERVAL_MS 0.0333f
#define HW_TIMER_INTERVAL_FREQ 30000L
Why do we need this megaAVR_Slow_PWM library
This library enables you to use ISR-based PWM channels on ATmega4809-based boards, such as UNO WiFi Rev2, AVR_Nano_Every, etc., using Arduino megaAVR core
to create and output PWM any GPIO pin. Because this library doesn't use the powerful purely hardware-controlled PWM with many limitations, the maximum PWM frequency is currently limited at 500Hz, which is still suitable for many real-life applications. Now you can change the PWM settings on-the-fly
This library enables you to use Interrupt from Hardware Timers on megaAVR-based boards to create and output PWM to pins. It now supports 16 ISR-based synchronized PWM channels, while consuming only 1 Hardware Timer. PWM interval can be very long (uint64_t microsecs / millisecs). The most important feature is they're ISR-based PWM channels. Therefore, their executions are not blocked by bad-behaving functions or tasks. This important feature is absolutely necessary for mission-critical tasks. These hardware PWM channels, using interrupt, still work even if other functions are blocking. Moreover, they are much more precise (certainly depending on clock frequency accuracy) than other software PWM using millis() or micros(). That's necessary if you need to measure some data requiring better accuracy.
As Hardware Timers are rare, and very precious assets of any board, this library now enables you to use up to 16 ISR-based synchronized PWM channels, while consuming only 1 Hardware Timer. Timers' interval is very long (ulong millisecs).
Now with these new 16 ISR-based PWM-channels, the maximum interval is practically unlimited (limited only by unsigned long milliseconds) while the accuracy is nearly perfect compared to software PWM channels.
The most important feature is they're ISR-based PWM channels. Therefore, their executions are not blocked by bad-behaving functions / tasks. This important feature is absolutely necessary for mission-critical tasks.
The ISR_8_PWMs_Array_Complex example will demonstrate the nearly perfect accuracy, compared to software PWM, by printing the actual period / duty-cycle in microsecs
of each of PWM-channels.
Being ISR-based PWM, their executions are not blocked by bad-behaving functions / tasks, such as connecting to WiFi, Internet or Blynk services. You can also have many (up to 16)
PWM channels to use.
This non-being-blocked important feature is absolutely necessary for mission-critical tasks.
You'll see software-based
SimpleTimer is blocked while system is connecting to WiFi / Internet / Blynk, as well as by blocking task
in loop(), using delay() function as an example. The elapsed time then is very unaccurate
Imagine you have a system with a mission-critical function, measuring water level and control the sump pump or doing something much more important. You normally use a software timer to poll, or even place the function in loop(). But what if another function is blocking the loop() or setup().
So your function might not be executed, and the result would be disastrous.
You'd prefer to have your function called, no matter what happening with other functions (busy loop, bug, etc.).
The correct choice is to use a Hardware Timer with Interrupt to call your function.
These hardware PWM channels, using interrupt, still work even if other functions are blocking. Moreover, they are much more precise (certainly depending on clock frequency accuracy) than other software PWM channels using millis() or micros(). That's necessary if you need to measure some data requiring better accuracy.
Functions using normal software PWM channels, relying on loop() and calling millis(), won't work if the loop() or setup() is blocked by certain operation. For example, certain function is blocking while it's connecting to WiFi or some services.
The catch is your function is now part of an ISR (Interrupt Service Routine), and must be lean / mean, and follow certain rules. More to read on:
- megaAVR-based boards such as UNO WiFi Rev2, AVR_Nano_Every, etc., using
Arduino megaAVR core
- megaAVR-based boards such as UNO WiFi Rev2, AVR_Nano_Every, ATmega4809, ATmega4808, ATmega3209, ATmega3208, ATmega1609, ATmega1608, ATmega809, ATmega808, etc., using
MegaCoreX megaAVR core
-
Inside the attached function, delay() won’t work and the value returned by millis() will not increment. Serial data received while in the function may be lost. You should declare as volatile any variables that you modify within the attached function.
-
Typically global variables are used to pass data between an ISR and the main program. To make sure variables shared between an ISR and the main program are updated correctly, declare them as volatile.
Arduino IDE 1.8.19+
for Arduino.Arduino megaAVR core 1.8.7+
for Arduino megaAVR boards. Use Arduino Board Manager to install..
MegaCoreX megaAVR core 1.1.0+
for Arduino megaAVR boards.. Follow How to install.
- To use with certain example
SimpleTimer library
for ISR_Timers_Array_Simple and ISR_16_Timers_Array_Complex examples.
The best and easiest way is to use Arduino Library Manager
. Search for megaAVR_Slow_PWM, then select / install the latest version.
You can also use this link for more detailed instructions.
Another way to install is to:
- Navigate to megaAVR_Slow_PWM page.
- Download the latest release
megaAVR_Slow_PWM-master.zip
. - Extract the zip file to
megaAVR_Slow_PWM-master
directory - Copy whole
megaAVR_Slow_PWM-master
folder to Arduino libraries' directory such as~/Arduino/libraries/
.
- Install VS Code
- Install PlatformIO
- Install megaAVR_Slow_PWM library by using Library Manager. Search for megaAVR_Slow_PWM in Platform.io Author's Libraries
- Use included platformio.ini file from examples to ensure that all dependent libraries will installed automatically. Please visit documentation for the other options and examples at Project Configuration File
The current library implementation, using xyz-Impl.h
instead of standard xyz.cpp
, possibly creates certain Multiple Definitions
Linker error in certain use cases.
You can include this .hpp
file
// Can be included as many times as necessary, without `Multiple Definitions` Linker Error
#include "megaAVR_Slow_PWM.hpp" //https://github.com/khoih-prog/megaAVR_Slow_PWM
in many files. But be sure to use the following .h
file in just 1 .h
, .cpp
or .ino
file, which must not be included in any other file, to avoid Multiple Definitions
Linker Error
// To be included only in main(), .ino with setup() to avoid `Multiple Definitions` Linker Error
#include "megaAVR_Slow_PWM.h" //https://github.com/khoih-prog/megaAVR_Slow_PWM
Check the new multiFileProject example for a HOWTO
demo.
Have a look at the discussion in Different behaviour using the src_cpp or src_h lib #80
TCB0-TCB3 are 16-bit timers.
Before using any Timer, you have to make sure the Timer has not been used by any other purpose.
// Select USING_16MHZ == true for 16MHz to Timer TCBx => shorter timer, but better accuracy
// Select USING_8MHZ == true for 8MHz to Timer TCBx => shorter timer, but better accuracy
// Select USING_250KHZ == true for 250KHz to Timer TCBx => shorter timer, but better accuracy
// Not select for default 250KHz to Timer TCBx => longer timer, but worse accuracy
#define USING_16MHZ true
#define USING_8MHZ false
#define USING_250KHZ false
#define USE_TIMER_0 false
#define USE_TIMER_1 true
#define USE_TIMER_2 false
#define USE_TIMER_3 false
// Init megaAVR_SLOW_PWM, each can service 16 different ISR-based PWM channels
megaAVR_SLOW_PWM ISR_PWM;
void irqCallbackStartFunc()
{
}
void irqCallbackStopFunc()
{
}
void setup()
{
....
// You can use this with PWM_Freq in Hz
ISR_PWM.setPWM(PWM_Pin, PWM_Freq, PWM_DutyCycle, irqCallbackStartFunc, irqCallbackStopFunc);
....
}
- ISR_8_PWMs_Array
- ISR_8_PWMs_Array_Complex
- ISR_8_PWMs_Array_Simple
- ISR_Changing_PWM
- ISR_Modify_PWM
- multiFileProject New
Example ISR_8_PWMs_Array_Complex
The following is the sample terminal output when running example ISR_8_PWMs_Array_Complex megaAVR Nano Every to demonstrate how to use multiple PWM channels with complex callback functions, the accuracy of ISR Hardware PWM-channels, especially when system is very busy. The ISR PWM-channels is running exactly according to corresponding programmed periods and duty-cycles
Starting ISR_8_PWMs_Array_Complex on megaAVR Nano Every
megaAVR_SLOW_PWM v1.2.1
CPU Frequency = 16 MHz
TCB Clock Frequency = 16MHz for highest accuracy
[PWM] TCB 1
[PWM] ==================
[PWM] Init, Timer = 1
[PWM] CTRLB = 0
[PWM] CCMP = 65535
[PWM] INTCTRL = 0
[PWM] CTRLA = 1
[PWM] ==================
[PWM] Frequency = 30000.00 , CLK_TCB_FREQ = 16000000
[PWM] setFrequency: _CCMPValueRemaining = 533
Starting ITimer1 OK, micros() = 2013580
Channel : 0 Period : 1000000 OnTime : 50000 Start_Time : 2015636
Channel : 1 Period : 500000 OnTime : 50000 Start_Time : 2021248
Channel : 2 Period : 333333 OnTime : 66666 Start_Time : 2027536
Channel : 3 Period : 250000 OnTime : 75000 Start_Time : 2033868
Channel : 4 Period : 200000 OnTime : 80000 Start_Time : 2040224
Channel : 5 Period : 166666 OnTime : 74999 Start_Time : 2047760
Channel : 6 Period : 142857 OnTime : 71428 Start_Time : 2056708
Channel : 7 Period : 125000 OnTime : 68750 Start_Time : 2065380
SimpleTimer (us): 2000, us : 12076620, Dus : 10061960
PWM Channel : 0, prog Period (ms): 1000.00, actual : 1000016, prog DutyCycle : 5, actual : 5.00
PWM Channel : 1, prog Period (ms): 500.00, actual : 500020, prog DutyCycle : 10, actual : 9.99
PWM Channel : 2, prog Period (ms): 333.33, actual : 333376, prog DutyCycle : 20, actual : 19.97
PWM Channel : 3, prog Period (ms): 250.00, actual : 250008, prog DutyCycle : 30, actual : 30.00
PWM Channel : 4, prog Period (ms): 200.00, actual : 200044, prog DutyCycle : 40, actual : 40.00
PWM Channel : 5, prog Period (ms): 166.67, actual : 166640, prog DutyCycle : 45, actual : 45.01
PWM Channel : 6, prog Period (ms): 142.86, actual : 142872, prog DutyCycle : 50, actual : 50.00
PWM Channel : 7, prog Period (ms): 125.00, actual : 124980, prog DutyCycle : 55, actual : 55.02
SimpleTimer (us): 2000, us : 22180588, Dus : 10103968
PWM Channel : 0, prog Period (ms): 1000.00, actual : 1000016, prog DutyCycle : 5, actual : 4.99
PWM Channel : 1, prog Period (ms): 500.00, actual : 500056, prog DutyCycle : 10, actual : 9.99
PWM Channel : 2, prog Period (ms): 333.33, actual : 333380, prog DutyCycle : 20, actual : 19.98
PWM Channel : 3, prog Period (ms): 250.00, actual : 249972, prog DutyCycle : 30, actual : 29.99
PWM Channel : 4, prog Period (ms): 200.00, actual : 199992, prog DutyCycle : 40, actual : 39.97
PWM Channel : 5, prog Period (ms): 166.67, actual : 166716, prog DutyCycle : 45, actual : 44.97
PWM Channel : 6, prog Period (ms): 142.86, actual : 142992, prog DutyCycle : 50, actual : 49.90
PWM Channel : 7, prog Period (ms): 125.00, actual : 125108, prog DutyCycle : 55, actual : 54.90
SimpleTimer (us): 2000, us : 32320408, Dus : 10139820
PWM Channel : 0, prog Period (ms): 1000.00, actual : 1000084, prog DutyCycle : 5, actual : 4.99
PWM Channel : 1, prog Period (ms): 500.00, actual : 500088, prog DutyCycle : 10, actual : 9.99
PWM Channel : 2, prog Period (ms): 333.33, actual : 333388, prog DutyCycle : 20, actual : 19.97
PWM Channel : 3, prog Period (ms): 250.00, actual : 250052, prog DutyCycle : 30, actual : 29.96
PWM Channel : 4, prog Period (ms): 200.00, actual : 200060, prog DutyCycle : 40, actual : 39.97
PWM Channel : 5, prog Period (ms): 166.67, actual : 166640, prog DutyCycle : 45, actual : 44.96
PWM Channel : 6, prog Period (ms): 142.86, actual : 142912, prog DutyCycle : 50, actual : 49.93
PWM Channel : 7, prog Period (ms): 125.00, actual : 125084, prog DutyCycle : 55, actual : 54.91
SimpleTimer (us): 2000, us : 42478424, Dus : 10158016
PWM Channel : 0, prog Period (ms): 1000.00, actual : 1000048, prog DutyCycle : 5, actual : 5.00
PWM Channel : 1, prog Period (ms): 500.00, actual : 500020, prog DutyCycle : 10, actual : 9.99
PWM Channel : 2, prog Period (ms): 333.33, actual : 333384, prog DutyCycle : 20, actual : 19.97
PWM Channel : 3, prog Period (ms): 250.00, actual : 250076, prog DutyCycle : 30, actual : 29.96
PWM Channel : 4, prog Period (ms): 200.00, actual : 200116, prog DutyCycle : 40, actual : 39.93
PWM Channel : 5, prog Period (ms): 166.67, actual : 166704, prog DutyCycle : 45, actual : 44.97
PWM Channel : 6, prog Period (ms): 142.86, actual : 142944, prog DutyCycle : 50, actual : 49.94
PWM Channel : 7, prog Period (ms): 125.00, actual : 125056, prog DutyCycle : 55, actual : 54.93
SimpleTimer (us): 2000, us : 52642384, Dus : 10163960
PWM Channel : 0, prog Period (ms): 1000.00, actual : 1000080, prog DutyCycle : 5, actual : 4.99
PWM Channel : 1, prog Period (ms): 500.00, actual : 500028, prog DutyCycle : 10, actual : 9.99
PWM Channel : 2, prog Period (ms): 333.33, actual : 333420, prog DutyCycle : 20, actual : 19.97
PWM Channel : 3, prog Period (ms): 250.00, actual : 250012, prog DutyCycle : 30, actual : 29.97
PWM Channel : 4, prog Period (ms): 200.00, actual : 200016, prog DutyCycle : 40, actual : 39.96
PWM Channel : 5, prog Period (ms): 166.67, actual : 166744, prog DutyCycle : 45, actual : 44.98
PWM Channel : 6, prog Period (ms): 142.86, actual : 142884, prog DutyCycle : 50, actual : 49.94
PWM Channel : 7, prog Period (ms): 125.00, actual : 124988, prog DutyCycle : 55, actual : 54.98
The following is the sample terminal output when running example ISR_8_PWMs_Array on megaAVR Nano Every to demonstrate how to use multiple PWM channels with simple callback functions.
Starting ISR_8_PWMs_Array on megaAVR Nano Every
megaAVR_SLOW_PWM v1.2.1
CPU Frequency = 16 MHz
TCB Clock Frequency = 16MHz for highest accuracy
[PWM] TCB 1
[PWM] ==================
[PWM] Init, Timer = 1
[PWM] CTRLB = 0
[PWM] CCMP = 65535
[PWM] INTCTRL = 0
[PWM] CTRLA = 1
[PWM] ==================
[PWM] Frequency = 30000.00 , CLK_TCB_FREQ = 16000000
[PWM] setFrequency: _CCMPValueRemaining = 533
Starting ITimer1 OK, micros() = 2012864
Channel : 0 Period : 1000000 OnTime : 50000 Start_Time : 2014864
Channel : 1 Period : 500000 OnTime : 50000 Start_Time : 2020544
Channel : 2 Period : 333333 OnTime : 66666 Start_Time : 2026820
Channel : 3 Period : 250000 OnTime : 75000 Start_Time : 2033152
Channel : 4 Period : 200000 OnTime : 80000 Start_Time : 2039500
Channel : 5 Period : 166666 OnTime : 74999 Start_Time : 2046984
Channel : 6 Period : 142857 OnTime : 71428 Start_Time : 2055924
Channel : 7 Period : 125000 OnTime : 68750 Start_Time : 2064600
The following is the sample terminal output when running example ISR_8_PWMs_Array_Simple on megaAVR Nano Every to demonstrate how to use multiple PWM channels.
Starting ISR_8_PWMs_Array_Simple on megaAVR Nano Every
megaAVR_SLOW_PWM v1.2.1
CPU Frequency = 16 MHz
TCB Clock Frequency = 16MHz for highest accuracy
[PWM] TCB 1
[PWM] ==================
[PWM] Init, Timer = 1
[PWM] CTRLB = 0
[PWM] CCMP = 65535
[PWM] INTCTRL = 0
[PWM] CTRLA = 1
[PWM] ==================
[PWM] Frequency = 30000.00 , CLK_TCB_FREQ = 16000000
[PWM] setFrequency: _CCMPValueRemaining = 533
Starting ITimer1 OK, micros() = 2012448
Channel : 0 Period : 1000000 OnTime : 50000 Start_Time : 2014448
Channel : 1 Period : 500000 OnTime : 50000 Start_Time : 2020112
Channel : 2 Period : 333333 OnTime : 66666 Start_Time : 2026388
Channel : 3 Period : 250000 OnTime : 75000 Start_Time : 2032672
Channel : 4 Period : 200000 OnTime : 80000 Start_Time : 2039076
Channel : 5 Period : 166666 OnTime : 74999 Start_Time : 2046548
Channel : 6 Period : 142857 OnTime : 71428 Start_Time : 2055500
Channel : 7 Period : 125000 OnTime : 68750 Start_Time : 2064172
The following is the sample terminal output when running example ISR_Modify_PWM on megaAVR Nano Every to demonstrate how to modify PWM settings on-the-fly without deleting the PWM channel
Starting ISR_Modify_PWM on megaAVR Nano Every
megaAVR_SLOW_PWM v1.2.1
CPU Frequency = 16 MHz
TCB Clock Frequency = 16MHz for highest accuracy
[PWM] TCB 1
[PWM] ==================
[PWM] Init, Timer = 1
[PWM] CTRLB = 0
[PWM] CCMP = 65535
[PWM] INTCTRL = 0
[PWM] CTRLA = 1
[PWM] ==================
[PWM] Frequency = 30000.00 , CLK_TCB_FREQ = 16000000
[PWM] setFrequency: _CCMPValueRemaining = 533
Starting ITimer1 OK, micros() = 2012696
Using PWM Freq = 200.00, PWM DutyCycle = 1.00
Channel : 0 Period : 5000 OnTime : 50 Start_Time : 2018636
Channel : 0 Period : 10000 OnTime : 555 Start_Time : 12026148
Channel : 0 Period : 5000 OnTime : 50 Start_Time : 22018624
Channel : 0 Period : 10000 OnTime : 555 Start_Time : 32026252
Channel : 0 Period : 5000 OnTime : 50 Start_Time : 42023732
Channel : 0 Period : 10000 OnTime : 555 Start_Time : 52031224
Channel : 0 Period : 5000 OnTime : 50 Start_Time : 62023700
Channel : 0 Period : 10000 OnTime : 555 Start_Time : 72031192
The following is the sample terminal output when running example ISR_Changing_PWM on megaAVR Nano Every to demonstrate how to modify PWM settings on-the-fly by deleting the PWM channel and reinit the PWM channel
Starting ISR_Changing_PWM on megaAVR Nano Every
megaAVR_SLOW_PWM v1.2.1
CPU Frequency = 16 MHz
TCB Clock Frequency = 16MHz for highest accuracy
[PWM] TCB 1
[PWM] ==================
[PWM] Init, Timer = 1
[PWM] CTRLB = 0
[PWM] CCMP = 65535
[PWM] INTCTRL = 0
[PWM] CTRLA = 1
[PWM] ==================
[PWM] Frequency = 30000.00 , CLK_TCB_FREQ = 16000000
[PWM] setFrequency: _CCMPValueRemaining = 533
Starting ITimer1 OK, micros() = 2012575
Using PWM Freq = 1.00, PWM DutyCycle = 50.00
Channel : 0 Period : 1000000 OnTime : 500000 Start_Time : 2018587
Using PWM Freq = 2.00, PWM DutyCycle = 90.00
Channel : 0 Period : 500000 OnTime : 450000 Start_Time : 12026819
Using PWM Freq = 1.00, PWM DutyCycle = 50.00
Channel : 0 Period : 1000000 OnTime : 500000 Start_Time : 22033842
Using PWM Freq = 2.00, PWM DutyCycle = 90.00
Channel : 0 Period : 500000 OnTime : 450000 Start_Time : 32041005
Using PWM Freq = 1.00, PWM DutyCycle = 50.00
Channel : 0 Period : 1000000 OnTime : 500000 Start_Time : 42048026
Using PWM Freq = 2.00, PWM DutyCycle = 90.00
Channel : 0 Period : 500000 OnTime : 450000 Start_Time : 52055177
Using PWM Freq = 1.00, PWM DutyCycle = 50.00
Channel : 0 Period : 1000000 OnTime : 500000 Start_Time : 62062218
Using PWM Freq = 2.00, PWM DutyCycle = 90.00
Channel : 0 Period : 500000 OnTime : 450000 Start_Time : 72069373
Using PWM Freq = 1.00, PWM DutyCycle = 50.00
Channel : 0 Period : 1000000 OnTime : 500000 Start_Time : 82076404
Using PWM Freq = 2.00, PWM DutyCycle = 90.00
Channel : 0 Period : 500000 OnTime : 450000 Start_Time : 92083560
Using PWM Freq = 1.00, PWM DutyCycle = 50.00
Channel : 0 Period : 1000000 OnTime : 500000 Start_Time : 102090588
The following is the sample terminal output when running example ISR_8_PWMs_Array_Complex MegaCoreX Nano Every to demonstrate how to use multiple PWM channels with complex callback functions, the accuracy of ISR Hardware PWM-channels, especially when system is very busy. The ISR PWM-channels is running exactly according to corresponding programmed periods and duty-cycles
Starting ISR_8_PWMs_Array_Complex on MegaCoreX Nano Every
megaAVR_SLOW_PWM v1.2.1
CPU Frequency = 16 MHz
TCB Clock Frequency = 16MHz for highest accuracy
[PWM] TCB 1
[PWM] ==================
[PWM] Init, Timer = 1
[PWM] CTRLB = 0
[PWM] CCMP = 65535
[PWM] INTCTRL = 0
[PWM] CTRLA = 1
[PWM] ==================
[PWM] Frequency = 30000.00 , CLK_TCB_FREQ = 16000000
[PWM] setFrequency: _CCMPValueRemaining = 533
Starting ITimer1 OK, micros() = 2013258
Channel : 0 Period : 1000000 OnTime : 50000 Start_Time : 2015189
Channel : 1 Period : 500000 OnTime : 50000 Start_Time : 2020809
Channel : 2 Period : 333333 OnTime : 66666 Start_Time : 2027083
Channel : 3 Period : 250000 OnTime : 75000 Start_Time : 2033362
Channel : 4 Period : 200000 OnTime : 80000 Start_Time : 2039701
Channel : 5 Period : 166666 OnTime : 74999 Start_Time : 2046513
Channel : 6 Period : 142857 OnTime : 71428 Start_Time : 2054578
Channel : 7 Period : 125000 OnTime : 68750 Start_Time : 2063400
SimpleTimer (us): 2000, us : 12073263, Dus : 10058994
PWM Channel : 0, prog Period (ms): 1000.00, actual : 1000082, prog DutyCycle : 5, actual : 4.99
PWM Channel : 1, prog Period (ms): 500.00, actual : 500023, prog DutyCycle : 10, actual : 9.99
PWM Channel : 2, prog Period (ms): 333.33, actual : 333377, prog DutyCycle : 20, actual : 19.98
PWM Channel : 3, prog Period (ms): 250.00, actual : 250008, prog DutyCycle : 30, actual : 29.99
PWM Channel : 4, prog Period (ms): 200.00, actual : 200010, prog DutyCycle : 40, actual : 39.99
PWM Channel : 5, prog Period (ms): 166.67, actual : 166667, prog DutyCycle : 45, actual : 45.00
PWM Channel : 6, prog Period (ms): 142.86, actual : 142869, prog DutyCycle : 50, actual : 50.00
PWM Channel : 7, prog Period (ms): 125.00, actual : 125015, prog DutyCycle : 55, actual : 55.01
SimpleTimer (us): 2000, us : 22182603, Dus : 10109340
PWM Channel : 0, prog Period (ms): 1000.00, actual : 1000049, prog DutyCycle : 5, actual : 4.99
PWM Channel : 1, prog Period (ms): 500.00, actual : 500022, prog DutyCycle : 10, actual : 9.99
PWM Channel : 2, prog Period (ms): 333.33, actual : 333410, prog DutyCycle : 20, actual : 19.98
PWM Channel : 3, prog Period (ms): 250.00, actual : 250049, prog DutyCycle : 30, actual : 29.98
PWM Channel : 4, prog Period (ms): 200.00, actual : 200058, prog DutyCycle : 40, actual : 39.97
PWM Channel : 5, prog Period (ms): 166.67, actual : 166641, prog DutyCycle : 45, actual : 44.96
PWM Channel : 6, prog Period (ms): 142.86, actual : 142910, prog DutyCycle : 50, actual : 49.93
PWM Channel : 7, prog Period (ms): 125.00, actual : 125054, prog DutyCycle : 55, actual : 54.93
SimpleTimer (us): 2000, us : 32535226, Dus : 10352623
PWM Channel : 0, prog Period (ms): 1000.00, actual : 1000049, prog DutyCycle : 5, actual : 4.99
PWM Channel : 1, prog Period (ms): 500.00, actual : 500026, prog DutyCycle : 10, actual : 9.99
PWM Channel : 2, prog Period (ms): 333.33, actual : 333385, prog DutyCycle : 20, actual : 19.98
PWM Channel : 3, prog Period (ms): 250.00, actual : 250013, prog DutyCycle : 30, actual : 29.98
PWM Channel : 4, prog Period (ms): 200.00, actual : 200016, prog DutyCycle : 40, actual : 39.96
PWM Channel : 5, prog Period (ms): 166.67, actual : 166673, prog DutyCycle : 45, actual : 44.98
PWM Channel : 6, prog Period (ms): 142.86, actual : 142877, prog DutyCycle : 50, actual : 49.94
PWM Channel : 7, prog Period (ms): 125.00, actual : 125057, prog DutyCycle : 55, actual : 54.94
SimpleTimer (us): 2000, us : 42973223, Dus : 10437997
PWM Channel : 0, prog Period (ms): 1000.00, actual : 1000015, prog DutyCycle : 5, actual : 5.00
PWM Channel : 1, prog Period (ms): 500.00, actual : 500060, prog DutyCycle : 10, actual : 9.99
PWM Channel : 2, prog Period (ms): 333.33, actual : 333346, prog DutyCycle : 20, actual : 19.97
PWM Channel : 3, prog Period (ms): 250.00, actual : 249974, prog DutyCycle : 30, actual : 29.97
PWM Channel : 4, prog Period (ms): 200.00, actual : 200042, prog DutyCycle : 40, actual : 39.98
PWM Channel : 5, prog Period (ms): 166.67, actual : 166633, prog DutyCycle : 45, actual : 44.99
PWM Channel : 6, prog Period (ms): 142.86, actual : 142872, prog DutyCycle : 50, actual : 49.98
PWM Channel : 7, prog Period (ms): 125.00, actual : 125017, prog DutyCycle : 55, actual : 55.01
Debug is enabled by default on Serial.
You can also change the debugging level _PWM_LOGLEVEL_
from 0 to 4
// Don't define _PWM_LOGLEVEL_ > 0. Only for special ISR debugging only. Can hang the system.
#define _PWM_LOGLEVEL_ 0
If you get compilation errors, more often than not, you may need to install a newer version of the core for Arduino boards.
Sometimes, the library will only work if you update the board core to the latest version because I am using newly added functions.
Submit issues to: megaAVR_Slow_PWM issues
- Search for bug and improvement.
- Similar features for remaining Arduino boards
- Basic hardware multi-channel PWM for Arduino megaAVR boards, such as UNO WiFi Rev2, AVR_Nano_Every, etc. using
Arduino megaAVR core
- Add Table of Contents
- Add functions to modify PWM settings on-the-fly
- Fix
multiple-definitions
linker error - Optimize library code by using
reference-passing
instead ofvalue-passing
- Add support to
MegaCoreX megaAVR core
core, including ATmega4809, ATmega4808, ATmega3209, ATmega3208, ATmega1609, ATmega1608, ATmega809 and ATmega808 - Improve accuracy by using
float
, instead ofuint32_t
fordutycycle
- DutyCycle to be optionally updated at the end current PWM period instead of immediately.
- Display informational warning only when
_PWM_LOGLEVEL_
> 3
Many thanks for everyone for bug reporting, new feature suggesting, testing and contributing to the development of this library.
If you want to contribute to this project:
- Report bugs and errors
- Ask for enhancements
- Create issues and pull requests
- Tell other people about this library
- The library is licensed under MIT
Copyright (c) 2021- Khoi Hoang