ezChronos headcount and first 2011 project start ?

[Catalin]

I believe there are at least 3 ezChronos owners around and since now I am looking into a 'HEQ firmware' for those models (and not necessarily just for my own watch) there might be a few questions involved:

- who has one (or more) ?

- have you tried programming a different firmware inside (for instance the supplied data-logger) ?

- do you have other temperature-related 'hardware' (similar to the mini-fridge that we have discussed in other threads) ?

- are you willing to do watch accuracy-measurements (or have you done so already - not necessary on the ezChronos but on any quartz watch - for instance with the video method) ?

There are still a number of problems to be solved but it seems that in the absence of a special (dedicated) hardware device to 'calibrate' each watch, the simplest approach would be to assume that the raw quartz from inside has a temperature response that can be well described with something like a*t^2 + b*t + c = 0 , but until we see otherwise we should assume that the a/b/c coefficients above are specific to each quartz and we should each try to measure those with decent accuracy - which IMHO would be feasible by having 3 timing measurements of around 2 weeks each at 3 'temperature points' - and since it is very unlikely that all of us will be able to keep the watch within 0.1 C for a full 2 weeks it is acceptable to keep it in a range of plus or minus 1-2C but with temperature-logging in effect for the interval (which will also help us in calibrating the results against the actual temperature that is seen by the watch). The 3 'target temperatures' should be something like 'fridge temperature', 'room temperature' and 'warm temperature'.

We should also discuss if it might be OK for this thread to become the 'home' for the 'ezChronos HEQ' or if we will just use some other approach.

[webvan]

Sounds good to me!

Let's see :
1. One, the 915Mhz version
2. Yes, I switched to the datalogger firmware thanks to your instructions (copied below)
3. No, just my fridge, office for room and wrist for worn
I had it in the fridge for 15 days but unfortunately didn't make a precise note of the time for accuracy testing (I was testing the Precisionist and 8F35), all I can see is that it is now running 20 seconds fast and looking at the Datalogger PC app it seems like I set it on 01/09, presumably at the correct time, so that's not too good. The problem with the datalogger mode is that you can't set the time directly on the watch. Will reset it now.
4. Yes

Other info

Logging capability : logging only temperature at the maximum 1/255s rate I got 11.25 days
start : 12.01.2011,13:29:22,0,17.6,0
end : 23.01.2011,20:55:22,0,3.5,0

How to flash to datalogger firmware :
Copied from another topic :

Catalin : To switch to the data logger you need to go to RFBSL mode (the one where you can program a new firmware over wireless) and then program

\Program Files\Texas Instruments\eZ430-Chronos\Recovery\Chronos Watch\Applications\eZ430_Chronos_ Datalogger_XXXMHz_1_5.txt

The datalogger is an alternate smaller firmware (4 top + 4 bottom modes, vs 7+8 on the 'normal' version) where you have to use a separate PC program to 'sync' (Chronos Data Logger vs. Chronos Control Center) but it can record temperatures - at first I was also logging the altitude (as it could be seen in the file above) but on the current segment I am only logging temperature and I am curious if I can go over one week without having to download and erase the data

[Catalin]

...
3. No, just my fridge, office for room and wrist for worn
I had it in the fridge for 15 days but unfortunately didn't make a precise note of the time for accuracy testing (I was testing the Precisionist and 8F35), all I can see is that it is now running 20 seconds fast and looking at the Datalogger PC app it seems like I set it on 01/09, presumably at the correct time, so that not too good. The problem with the datalogger mode is that you can't set the time directly on the watch. Will reset it inow.
...

Yes, the code is very tight on the existing datalogger - but the bigger problem with the existing program is that when you set anything (from the PC program) you also change the internal 'temperature calibration' - I was very careful in my first two tests but in the 3rd (ended this Sunday) I have a 0.2C difference in the average (which could also be from the fact that I had in tests two solar watches and I kept them and the ezChronos for a few hours on 2 days in a 'crown up, face to the sun' position instead of the normal 'face down on the warm source' position).

The other problems with the existing datalogger PC program and watch firmware are that reading time can only be done with 1 second accuracy and calibration values can not be read (or set with some decent repeatable accuracy).

Coding a slightly better one proved to be a small pain - the 'free CCS' (code-size limited) has a buggy library and for the moment can not be used reliably, and using msp430-gcc was also quite 'unfriendly' - since I had first to update my cygwin environment and then basically compile msp430-gcc from sources. Right now I am using that on one system and the 'full CCS' on another with a 30-days evaluation license (which can be extended with another 90 days). And all that time lost was before playing with the PC-part (where the existing programs are Tcl/Tk compiled stuff)

The current plan is to try to have a more usable pair of firmware + PC-program probably by late Saturday / early Sunday and after that at some point start the first of those 3 timing + temperature logging measurements on my ezChronos (I will also double-check on that with the video method, which seems to be usable on it). Of course that the software will also be posted so that other people will be able to start their own tests

[5seikos]

Yes, the code is very tight on the existing datalogger - but the bigger problem with the existing program is that when you set anything (from the PC program) you also change the internal 'temperature calibration' - I was very careful in my first two tests but in the 3rd (ended this Sunday) I have a 0.2C difference in the average (which could also be from the fact that I had in tests two solar watches and I kept them and the ezChronos for a few hours on 2 days in a 'crown up, face to the sun' position instead of the normal 'face down on the warm source' position).

The other problems with the existing datalogger PC program and watch firmware are that reading time can only be done with 1 second accuracy and calibration values can not be read (or set with some decent repeatable accuracy).

Coding a slightly better one proved to be a small pain - the 'free CCS' (code-size limited) has a buggy library and for the moment can not be used reliably, and using msp430-gcc was also quite 'unfriendly' - since I had first to update my cygwin environment and then basically compile msp430-gcc from sources. Right now I am using that on one system and the 'full CCS' on another with a 30-days evaluation license (which can be extended with another 90 days). And all that time lost was before playing with the PC-part (where the existing programs are Tcl/Tk compiled stuff)

The current plan is to try to have a more usable pair of firmware + PC-program probably by late Saturday / early Sunday and after that at some point start the first of those 3 timing + temperature logging measurements on my ezChronos (I will also double-check on that with the video method, which seems to be usable on it). Of course that the software will also be posted so that other people will be able to start their own tests

If youre interested in simply recording the temperature, there are cheap voltmeters with thermocouple input and data logging using a serial port on a PC. Im sure there are small stand alone temp logger that transfer its data via usb. On these themocouples, they can read 1-2 degrees off. IRC RTDs are more precise.
As far as taking data faster than every 1 second, I think watches has enough mass that its temp will not likely change faster than that, even if the environments temp changes wildly.

I cant wait to get my quartz tender built and start getting some baseline data on my Bulova,

Rob T

[Catalin]

If youre interested in simply recording the temperature, there are cheap voltmeters with thermocouple input and data logging using a serial port on a PC. Im sure there are small stand alone temp logger that transfer its data via usb. On these themocouples, they can read 1-2 degrees off. IRC RTDs are more precise.
As far as taking data faster than every 1 second, I think watches has enough mass that its temp will not likely change faster than that, even if the environments temp changes wildly.

I cant wait to get my quartz tender built and start getting some baseline data on my Bulova,

Rob T

The major point is to have the temperature as read by the internal sensor from the watch - since that value will be used to implement the temperature correction

Also the observation on 1-second limit was not related to the temperature readings - the problem is that the API to read the time from inside the watch only returns to 1 second accuracy - so video method is a better alternative than that

[ronalddheld]

I have to US version and have switched to the datalogger. I expect to be doing more as the project progresses.

[5seikos]

The major point is to have the temperature as read by the internal sensor from the watch - since that value will be used to implement the temperature correction

Also the observation on 1-second limit was not related to the temperature readings - the problem is that the API to read the time from inside the watch only returns to 1 second accuracy - so video method is a better alternative than that

Sorry- My mistake. I didnt know youre T/C-ing your watch.
Is there a way to correct the pulses in the counters before its formatted for display? or later?

Regards,
Rob T

[Catalin]

Sorry- My mistake. I didnt know youre T/C-ing your watch.
Is there a way to correct the pulses in the counters before its formatted for display? or later?

Regards,
Rob T

Surprisingly NONE of the 3 major firmware that I am currently aware of (the original TI full watch plus datalogger and the OpenChronos project) are using the internal hardware clock (RTC_A) but instead use the separate timer (TIMER_A) for 1-second interrupts and do ALL the timekeeping in software - which is slightly simpler to implement/change but is probably a little suboptimal in terms of power consumption - however I guess not by much since the software still needs to update the display every second, so the CPU is still waken-up from low-power mode every 1 second in 'normal mode'.

[5seikos]

Surprisingly NONE of the 3 major firmware that I am currently aware of (the original TI full watch plus datalogger and the OpenChronos project) are using the internal hardware clock (RTC_A) but instead use the separate timer (TIMER_A) for 1-second interrupts and do ALL the timekeeping in software - which is slightly simpler to implement/change but is probably a little suboptimal in terms of power consumption - however I guess not by much since the software still needs to update the display every second, so the CPU is still waken-up from low-power mode every 1 second in 'normal mode'.

Given that the quartz crystal is probably of the regular 32k variety and with the +-15/month spread, have you figured out how well it would improve if you implement a stardard correction( based on a typical temp curve specs)? Do you know where the peak of the curve is on the temperature line? What is the 'ideal' average daily temp the manufacturer has chosen to use in calculating the error?
BTW- is the device's temp sensor designed to read environmental temp as opposed to the devices internal temp?

[ronalddheld]

I thought that it was internal temperatur but Catalin would know better.