PWMControl

PWMControl allows you to setup up to two PWM outputs by directly controlling the approprieate timer registers. The application is written for the STM32f103C8T6, a.k.a. BluePill, but may be easily ported to other controllers of the STM32 family.
After you've compiled and flashed the binary, a virtual COM-Port will appear that allows you to configure the timers.

Features

• Control two PWM outputs independently.
• Serial over USB. Just connect via USB and go!
• Extendable! Missing some features? PWMControl is easy to extend!

Commands

The command syntax is as follows:
<timer>:<command>[:<argument>]
where <timer> is the desired timer t1or t2.<command> and <argument> are described below:

Command	Function	Arguments
start	Starts the timer	N/A
stop	Stops timer execution	N/A
duty	Sets the duty cycle	0..100
period	Sets the period	[0..65535]
compare	Sets the comare value	[0..65535]
prescaler	Sets the prescaler	[0..65535]
status	Prints the status of the timer	N/A

Each recognized command is acknowledged with an OK. The only exception to this scheme is the helpcommand. In order to get help, just type help.

Examples

help example

The output of help is as follows:

help
OK
Syntax: <timer>:<command>[:<argument>]

<timer>...... [t1,t2]
    t1........... Timer connected to A8
    t2........... Timer connected to A9
<command>[:<arguments>]
    start ....... starts PWM
    stop ........ stops PWM
    duty ........ sets duty cycle [0..100]
    period ...... sets the period [0..65535]
    compare ..... sets compare value [0.65535]
    prescaler ... sets the prescaler [0..65535]
    status ...... prints the current configuration

status example

The output of t1:status may look as follows:

t1:status
OK
Clock: 72000000MHz
Prescaler: 0
Period: 80
Compare: 27

PWM example

In order to run timer1 with 50% dutycycle and a period of 1ms assuming the the clock is running at 72MHz issue the following commands:

t1:prescaler:719
OK
t1:period:99
OK
t1:compare:49
OK
t1:start
OK

t1:prescaler:7199 will set the prescaler to 719. At a clock speed of 72MHz the timer clock will become 100kHz. Then the period is set to 99 and compare 49. If you are confused due to of the odd values, dont't forget that the timer values period, prescaler and compare are always substracted by 1.

Pinout

Pin	Function
PA6	Timer1 Output
PA8	Timer2 Output