Re: Wrong time.sleep if time < 17ms

[Ian Molton]

This isnt a compiler specific problem, but you might want to try
disassembling the code and seeing whats different -

objdump -D is your friend :)

-Ian

On 15/08/2021 19:30, D.Umbricht wrote:
>  Hi all
> I try to move a go program from a raspberry pi to an arduino uno using
> tinygo on the arduino.
> The program works basically but there's one problem.
> For the multiplexing of LED's I use the time.sleep function.
> With time.sleep(17*time.Milliseconds) the delay is appr. 17ms.
> However whenever the sleep time is < 17ms it actually the delay is only
> appr. 50us.
> I assume a problem in the time library but are not an expert.
> 
> $tinygo version
> tinygo version 0.19.0 linux/amd64 (using go version go1.16.7 and LLVM
> version 11.0.0)
> 
> I use the following test program:
> package main
> 
> import (
>     "machine"
>     "time"
> )
> 
> var gpio = []machine.Pin{
>         machine.ADC0,
>         machine.ADC1,
>         machine.D2,
>         machine.D3,
>         machine.D4,
>         machine.D5,
> }
> 
> 
> func main() {
> 
>     // define gpio as output and set them LOW
>     for i := 0; i < len(gpio); i++ {
>         gpio[i].Configure(machine.PinConfig{Mode: machine.PinOutput})
>         gpio[i].Low()
>     }
> 
> 
>   for {
>        gpio[0].High()  // pulse is app. 4us wide
>        gpio[0].Low()
> 
>        gpio[1].High()
>        time.Sleep(time.Millisecond*50) // sleep time appr. 33.9ms
>        gpio[1].Low()
> 
>        gpio[2].High()
>        time.Sleep(50*time.Microsecond) // sleep time appr. 52us
>        gpio[2].Low()
> 
>        gpio[3].High()
>        time.Sleep(17*time.Millisecond) // sleep time appr. 17ms
>        gpio[3].Low()
> 
>        gpio[4].High()
>        time.Sleep(16*time.Millisecond) // sleep time appr. 48us
>        gpio[4].Low()
> 
> 
>     } //end forloop
> } //end
> 
> gcc version 5.4.0 (GCC)
> avr-libc/focal,focal,now 1:2.0.0+Atmel3.6.1-2 all [installed]
> 
> Any help in this matter is very much appreciated.
>