I rewrote write_bit() in OneWire.cpp to match (more or less) what was working on the maple. This seems to work for me without any delay(1);! Works on both the little ds18b20 sketch and the Examples>OneWire>DS18x20_temperature.
void OneWire::write_bit(uint8_t v)
{
IO_REG_TYPE mask=bitmask;
volatile IO_REG_TYPE *reg IO_REG_ASM = baseReg;
if (v & 1) {
// noInterrupts();
DIRECT_MODE_OUTPUT(reg, mask); // drive output low
DIRECT_WRITE_LOW(reg, mask);
delayMicroseconds(5);
// DIRECT_WRITE_HIGH(reg, mask); // drive output high
DIRECT_MODE_INPUT(reg, mask); // let pin float, pull up will raise
delayMicroseconds(60);
//interrupts();
} else {
//noInterrupts();
DIRECT_MODE_OUTPUT(reg, mask); // drive output low
DIRECT_WRITE_LOW(reg, mask);
delayMicroseconds(60);
DIRECT_MODE_INPUT(reg, mask); // let pin float, pull up will raise
//DIRECT_WRITE_HIGH(reg, mask); // drive output high
//interrupts();
}
delayMicroseconds(10); // 10uSec recovery time
}
I combined mantoui's updated OneWire::write_bit function along with the changes made by alvesjc and I'm now able to run the DS18x20_Temperature right out of the box.
This effort should go a long way in getting other people moved over to the Due because so many projects have requirements to read temperatures and interact with other one wire devices.
Thanks for all your help in getting this working.
I've put all the stuff in a zip file for others to test without having to edit the files.
I'm current the de-facto maintainer of OneWire, but only because it was essentially abandoned when I picked it up and fixed the many bugs. If anyone else really wants the position, it's open....
Long-term, is the ODSR (presumably will work starting with 1.5.2) or CODR and SODR approach the best way?
mantoui:
I rewrote write_bit() in OneWire.cpp to match (more or less) what was working on the maple. This seems to work for me without any delay(1);! Works on both the little ds18b20 sketch and the Examples>OneWire>DS18x20_temperature.
I combined mantoui's updated OneWire::write_bit function along with the changes made by alvesjc and I'm now able to run the DS18x20_Temperature right out of the box.
This effort should go a long way in getting other people moved over to the Due because so many projects have requirements to read temperatures and interact with other one wire devices.
Thanks for all your help in getting this working.
I've put all the stuff in a zip file for others to test without having to edit the files.
So many people already complained about onewire, so I thought you're just gone of the Arduino world and took the initiative to try to make this work for everyone in this great new platform.
I has needing this lib for my project, so I started to dig on this.
You're most welcome to include the changes in your git!
Though read_bit() seemed to be working, I modified it as well to match the maple version. The two sketches seemed to work with the slimmer version. NO delay(1)'s required.
uint8_t OneWire::read_bit(void)
{
IO_REG_TYPE mask=bitmask;
volatile IO_REG_TYPE *reg IO_REG_ASM = baseReg;
uint8_t r;
DIRECT_MODE_OUTPUT(reg, mask);
DIRECT_WRITE_LOW(reg, mask);
delayMicroseconds(5);
DIRECT_MODE_INPUT(reg, mask); // let pin float, pull up will raise
delayMicroseconds(5);
r = DIRECT_READ(reg, mask);
delayMicroseconds(60);
return r;
}
alvesjc:
I' had it running with other timers, but would have failures from time to time, some of them were very spaced in time.
I can believe that. Several of the code fragments above have the interrupt disable removed. If an interrupt occurs during a bit read or write, it will lengthen the timing. On ARM, the problem is probably less, because the process is so much faster, especially with interrupt overhead (the context is saved by hardware, utilizing a separate bus, rather than by code in the interrupt routine). This was one of the 2 major bugs before I made version 2.0.
I've been running the OneWire code that I posted in the ZIP file in a previous post for over 12 hours with no errors pulling data from three DS18B20's.
I have not been able to incorporate mantoui's updated read_bit function but I will do that later tonight when I'm home.
ROM = 28 A0 CE 49 3 0 0 55
Chip = DS18B20
Data = 1 A3 1 4B 46 7F FF D 10 CE CRC=CE
Temperature = 26.19 Celsius, 79.14 Fahrenheit
ROM = 28 F6 C3 49 3 0 0 25
Chip = DS18B20
Data = 1 A2 1 4B 46 7F FF E 10 D8 CRC=D8
Temperature = 26.12 Celsius, 79.03 Fahrenheit
ROM = 28 6B C7 49 3 0 0 C1
Chip = DS18B20
Data = 1 A3 1 4B 46 7F FF D 10 CE CRC=CE
Temperature = 26.19 Celsius, 79.14 Fahrenheit
No more addresses.
I noticed in the Examples folder there is also a sketch for a DS2408 which is an 8 channel addressable switch. I have a number of those lying around so I may be able to test the sketch later against one and let you know the results.
[quote author=Paul Stoffregen link=topic=141030.msg1067752#msg1067752 date=1357937038]
Does Due have a tone() function yet? If so, please output an infinite duration 15 kHz tone on a pin during the test.
I believe the tone functions are still not ported.
[/quote]
I'm not sure what this has to do with onewire thread, but I have a proof-of-concept tone(), see tone1.ino in