core13: An Arduino core for the Attiny13 *testers wanted*

[smeezekitty]

Where is the attiny def for boards.txt?

There is a lot of boards.txt that are kicking around.
Some are more correct than others. I hacked this together:

Code: [Select]


########################

attiny13a.name=Attiny 13A standalone 128khz
attiny13a.upload.using=arduino:arduinoisp
attiny13a.upload.maximum_size=1024
attiny13a.upload.speed=19200
attiny13a.bootloader.low_fuses=0x7b
attiny13a.bootloader.high_fuses=0xFF
attiny13a.bootloader.path=empty
attiny13a.bootloader.file=empty
attiny13a.bootloader.unlock_bits=0xFF
attiny13a.bootloader.lock_bits=0xFF
attiny13a.build.mcu=attiny13
attiny13a.build.f_cpu=128000L
attiny13a.build.core=core13
#######################

attiny13f.name=Attiny 13A standalone 600khz
attiny13f.upload.using=arduino:arduinoisp
attiny13f.upload.maximum_size=1024
attiny13f.upload.speed=19200
attiny13f.bootloader.low_fuses=0x69
attiny13f.bootloader.high_fuses=0xFF
attiny13f.bootloader.path=empty
attiny13f.bootloader.file=empty
attiny13f.bootloader.unlock_bits=0xFF
attiny13f.bootloader.lock_bits=0xFF
attiny13f.build.mcu=attiny13
attiny13f.build.f_cpu=600000L
attiny13f.build.core=core13
#######################

attiny13c.name=Attiny 13A standalone 1.2mhz
attiny13c.upload.using=arduino:arduinoisp
attiny13c.upload.maximum_size=1024
attiny13c.upload.speed=19200
attiny13c.bootloader.low_fuses=0x6a
attiny13c.bootloader.high_fuses=0xFF
attiny13c.bootloader.path=empty
attiny13c.bootloader.file=empty
attiny13c.bootloader.unlock_bits=0xFF
attiny13c.bootloader.lock_bits=0xFF
attiny13c.build.mcu=attiny13
attiny13c.build.f_cpu=1200000L
attiny13c.build.core=core13

#######################
attiny13d.name=Attiny 13A standalone 4.8Mhz
attiny13d.upload.using=arduino:arduinoisp
attiny13d.upload.maximum_size=1024
attiny13d.upload.speed=19200
attiny13d.bootloader.low_fuses=0x79
attiny13d.bootloader.high_fuses=0xFF
attiny13d.bootloader.path=empty
attiny13d.bootloader.file=empty
attiny13d.bootloader.unlock_bits=0xFF
attiny13d.bootloader.lock_bits=0xFF
attiny13d.build.mcu=attiny13
attiny13d.build.f_cpu=4800000L
attiny13d.build.core=core13
#######################
attiny13e.name=Attiny 13A standalone 9.6Mhz
attiny13e.upload.using=arduino:arduinoisp
attiny13e.upload.maximum_size=1024
attiny13e.upload.speed=19200
attiny13e.bootloader.low_fuses=0x7A
attiny13e.bootloader.high_fuses=0xFF
attiny13e.bootloader.path=empty
attiny13e.bootloader.file=empty
attiny13e.bootloader.unlock_bits=0xFF
attiny13e.bootloader.lock_bits=0xFF
attiny13e.build.mcu=attiny13
attiny13e.build.f_cpu=9600000L
attiny13e.build.core=core13


It works with Attiny13A?

It works on all Attiny13 series

[karlboll]

Yay! My AtTiny13A's just arrived. 10 days from Shenzhen to Scandinavia must be some kind of record :-)

[sudhirkhamari]

Just received two attiny13a PU.
Plan 1: use it to drive a 4-pin RGB led. User shud be able to control intensity of each color using a push-button.

Plan 2: use it to drive a single(may be multiple, but don't really need it now) WS2812 based neoPixcel. Here also user should be able to control the individual color using push buttons.

In both of above case, either 3 push switch can be used to change individual color intensity with a step value of say 32 or 64. OR 2 push switch can be used; one for select the color to change and other to change the color intensity by a step value.

Should I burn a bootloader to the tiny? Please suggest how can I keep the code below 1K.

[mcnobby]

Plan 2: use it to drive a single(may be multiple, but don't really need it now) WS2812 based neoPixcel. Here also user should be able to control the individual color using push buttons.

I did THIS on attiny13a, most is not relevant here, but I wrote a fast ws2812 driving routine in assembler which works a treat !!

[sudhirkhamari]

Thanks mcnobby. I hv gone through your post on dmx/attiny. I am planning to leverage from the same. This is the t13 i bought:http://m.ebay.com/itm/201190520005?nav=SEARCH
Could you please suggest me what should i put in boards.txt file.

[evildave_666]

I've found this WorldSemi library useful: https://github.com/cpldcpu/light_ws2812

I've used it on attiny13 with the raw avr libraries.

[mcnobby]

I use this boards.txt entry for 9.6mhz attiny13a

Code: [Select]

attiny13at9.name=ATtiny13 @ 9.6MHz (internal 9.6 MHz clock)
attiny13at9.bootloader.low_fuses=0x3a
attiny13at9.bootloader.high_fuses=0xff
attiny13at9.upload.maximum_size=1024
attiny13at9.build.mcu=attiny13
attiny13at9.build.f_cpu=1200000
attiny13at9.build.core=core13


and this entry for driving at 32mhz from an external clock

Code: [Select]


attiny13-32.name=ATtiny13A (32mhz MHz clock gen)
attiny13-32.bootloader.low_fuses=0x70
attiny13-32.bootloader.high_fuses=0xff
attiny13-32.upload.maximum_size=1024
attiny13-32.build.mcu=attiny13
attiny13-32.build.f_cpu=9600000L
attiny13-32.build.core=core13


[smeezekitty]

Just received two attiny13a PU.
Plan 1: use it to drive a 4-pin RGB led. User shud be able to control intensity of each color using a push-button.

Plan 2: use it to drive a single(may be multiple, but don't really need it now) WS2812 based neoPixcel. Here also user should be able to control the individual color using push buttons.

In both of above case, either 3 push switch can be used to change individual color intensity with a step value of say 32 or 64. OR 2 push switch can be used; one for select the color to change and other to change the color intensity by a step value.

Should I burn a bootloader to the tiny? Please suggest how can I keep the code below 1K.

The Attiny13 has 5 usable I/O pins so it should be okay to drive a 4 pin RGB LED
and two push buttons. You may be able to use multiplexing to use less I/O pins.

Keeping the code under 1k ... well you should follow common sense to optimize code
and then just try it out and see where it lands.

No bootloader needed when programming with SPi

I use this boards.txt entry for 9.6mhz attiny13a

This is wrong.

Code: [Select]


attiny13at9.build.f_cpu=1200000


should be

Code: [Select]


attiny13at9.build.f_cpu=9600000


[mcnobby]

This is wrong.

Code: [Select]


attiny13at9.build.f_cpu=1200000

should be

Code: [Select]


attiny13at9.build.f_cpu=9600000


I think I went through this before trying to set frequency to 9.6mhz, bot sure why I ended up with the first entry but it seems to work fine.

As far as I know low fuse bits 0 & 1 also select internal oscillator and divider.

Is F_CPU only in there as a contant for the compiler ?

[smeezekitty]

I think I went through this before trying to set frequency to 9.6mhz, bot sure why I ended up with the first entry but it seems to work fine.

As far as I know low fuse bits 0 & 1 also select internal oscillator and divider.

Is F_CPU only in there as a contant for the compiler ?

F_CPU is a constant used by avr-libc and any Arduino core.
If it is incorrect, all timing and delay functions will be wrong.
And the ADC may be set up incorrectly.

[mcnobby]

ah ok, so thats probably why I didnt notice any problem, if I wasnt using any timing related functions it wouldnt matter

Thanks for the heads up

[Winnie_The_Pooh]

hi!

analogWrite makes 4 KHz output frequency.

Is it possible to make it approx 10 times smaller? e.g. 400-800 Hz

Thanks!

[smeezekitty]

hi!

analogWrite makes 4 KHz output frequency.

Is it possible to make it approx 10 times smaller? e.g. 400-800 Hz

Thanks!

I'm curious why? To be honest, I have never actually measured
the frequency.

You could lower the microcontroller clock which would no doubt
slow down the PWM rate

[Winnie_The_Pooh]

I'm using PWM to dim LED driver. Manual says that pwm frequency should be lower than 1000 Hz.


Lowering the clock is a little bit brute


May be I can play with divider here:


void analogWrite(uint8_t pin, uint8_t val){


24
       if(pin == 0){
25
           TCCR0A |= (1 << COM0A1);
26
           OCR0A = (val / 16) * 16;


Changing COM0A1 to COM0A2 will encrease the divider to 8. I think so

Any side effects?

[smeezekitty]

I'm using PWM to dim LED driver. Manual says that pwm frequency should be lower than 1000 Hz.


Lowering the clock is a little bit brute


May be I can play with divider here:


void analogWrite(uint8_t pin, uint8_t val){


24
       if(pin == 0){
25
           TCCR0A |= (1 << COM0A1);
26
           OCR0A = (val / 16) * 16;


Changing COM0A1 to COM0A2 will encrease the divider to 8. I think so

Any side effects?

It should be okay. Just toss this

Code: [Select]


(val / 16) * 16


and make it just "val"

That was part of testing code that has since been removed. Newer versions fixed it