Search found 1055 matches

by mstrens
Mon May 15, 2017 6:41 am
Forum: openTx
Topic: Help needed for a lua script.
Replies: 5
Views: 212

Re: Help needed for a lua script.

OK, thanks, it works with other ID's (from the 28 valid).

Perhaps that I had to replace
sportTelemetryPush( 0x48 , 0x32 , 0x52FF , 0)
by
ret = sportTelemetryPush( 0x48 , 0x32 , 0x52FF , 0)
by mstrens
Sun May 14, 2017 5:52 pm
Forum: openTx
Topic: Help needed for a lua script.
Replies: 5
Views: 212

Re: Help needed for a lua script.

Thanks for your info.
I just modified my script in order to use 0x0D as sensor ID in the sportTelemetryPush() and it works.

If it is required to use this value, it should be useful to add it in the openTX documentation for this function.
by mstrens
Sun May 14, 2017 3:03 pm
Forum: openTx
Topic: Help needed for a lua script.
Replies: 5
Views: 212

Help needed for a lua script.

I would like to let my taranis send some commands to a sensor (openXsensor) connected to the Rx on the SPORT bus. I installed the latest version of openTx 2.2 on the taranis and I activated the options lua and luac in companion. I wrote a short lua script (here below). local timeprev local running =...
by mstrens
Tue May 09, 2017 6:46 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: I cant compile oXs with "ALT_TEMP_COMPENSATION"
Replies: 4
Views: 167

Re: I cant compile oXs with "ALT_TEMP_COMPENSATION"

Ok, I see: There is currently a bug. Even if it is a MS5611, it tries to compile the file for the BMP280 and the error occurs in this file. To avoid the compilation error, please make a small change in file oXs_BMP280.cpp. At line 51 there is currently #ifdef ALT_TEMP_COMPENSATION alt_temp_compensat...
by mstrens
Tue May 09, 2017 5:53 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: I cant compile oXs with "ALT_TEMP_COMPENSATION"
Replies: 4
Views: 167

Re: I cant compile oXs with "ALT_TEMP_COMPENSATION"

I presume you are using a BMP280 baro sensor. In fact the parameter defined by the line "#define ALT_TEMP_COMPENSATION 800" can only be used for a MS5611 sensor. I will change the code to avoid this compilation error in the future. In the mean time, please keep this line as comment in your config fi...
by mstrens
Thu May 04, 2017 7:07 am
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

I have no experience but I read that silicone can support temperature up to 300 °C. Still I am not sure that the most common one (for e.g. bathroom) can support 300°C. I see that there are plenty of offers when I search for silicone high temperature. I expect you can even find them in normal hobby s...
by mstrens
Wed May 03, 2017 8:22 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

I think that silicone support higher temp than epoxy.
by mstrens
Tue May 02, 2017 12:30 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

Perhaps you are becoming out of range for your multitester temp sensor? If you have an electric oven with a thermostat,I think it could be used. Accuracy of thermostat is probably be about 10 °c . So it will already be better than 50/60 degree. Alternative is an electric fryer. It has a thermostat t...
by mstrens
Mon May 01, 2017 5:05 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

the formula to calculate A B C based on the 3 sets of resistance/temperature is given in wikipedia
see here (under the title Steinhart–Hart coefficients)
https://en.wikipedia.org/wiki/Steinhart ... efficients

It is not so difficult to implement in xls
by mstrens
Mon May 01, 2017 4:06 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

As long as your NTC fit the datasheet, with the new formula you should get 150 °C when temperature is 150 °C because the parameters are just just calculated in order to get exactly 25, 100 and 150 when the resistors are equal to the values given by the datasheet. Errors at 25, 100 and 150 should be ...
by mstrens
Mon May 01, 2017 2:01 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

Ok, I just did it and it compiled But what about the other settings in the config file that i just changed as per your suggestion? Can they remain like that? Thanks João The 3 settings about #define TERMISTOR_NOMINAL 100000 // nominal resistor of NTC (in Ohm) #define TEMPERATURE_NOMINAL 25 // nomin...
by mstrens
Mon May 01, 2017 1:57 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

If later you want to get A B C parameters for your device instead of using the data from the datasheet, you could make 3 sets of measurement. - put the NTC in water at normal temperature and measure resistance with multimeter and temperature with a normal thermometer. - put the NTC in boiling water ...
by mstrens
Mon May 01, 2017 1:50 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

No need to comment something. New code overwrite the old one. I could cleant it up later.
by mstrens
Mon May 01, 2017 1:37 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

Currently at the end of file oXs_voltage.cpp you have some thing like float media = SERIE_RESISTOR / ( (1023000.0 / voltage ) - 1 ) ; float temperatura = media / TERMISTOR_NOMINAL; // (R/Ro) temperatura = log(temperatura); // ln(R/Ro) temperatura /= B_COEFFICIENT; // 1/B * ln(R/Ro) temperatura += 1....
by mstrens
Mon May 01, 2017 1:00 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

If you use the resistance you measured, you should normally get a better accuracy because you avoid already the 1% tolerance of the manufacter. In the mean time, I also calculated the A B C parameters based on your datatsheet for 25, 100 and 150 °c. Those parameters could now immediately be recalcul...
by mstrens
Mon May 01, 2017 12:29 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

I checked the datasheet of your thermistor. In fact the B_COEFFICIENT is not constant over the whole range of temperature. The value of 3950 is for the range 25/50 When I calculate it for the range 25/200, I get 4150 For best results over the range 100/150 you could apply following parameters (based...
by mstrens
Mon May 01, 2017 11:59 am
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

You can try changing B_COEFFICIENT. If you increase the value (by e.g. 100), you will probably get a lower value from oXs. This change will normally has a higher effect for the high temperatures. Better accuracy in the range 100 / 150 °c is possible if you can measure the resistor of NTC at about 10...
by mstrens
Mon May 01, 2017 9:46 am
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

I just made a test with one of my NTC connected to oXs. At room temperature, I got 20 °c and in water that had boiled a few second ago (NTC being in a plastic bac) I got 95 °c In a second test I got about 105 °c but I suspect that the resistance was to low due to some humidity. So it seems me that o...
by mstrens
Mon May 01, 2017 6:43 am
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

I did not saw it, but it confirms that resistors should be about 7k at 100 °C
by mstrens
Sun Apr 30, 2017 8:01 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

I checked again the formula (based on documentation on the web) and it seems me OK. Still I got some thermistors from aliexpress and I made a test. My thermistors where given as 100k with Beta 3950. When I measure the resistance with an ohmmeter I get - 100 k at 25 °c (OK) - 7 k at 100 °c (boiling ...
by mstrens
Sun Apr 30, 2017 4:26 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

FYI, I just made a test with the 5 thermistor I got. Putting them at the same time in boiling water, I got some differences in the resistance (measured with an ohmmeter). It varies from 6.7 k up to 7.k. Keeping the same B_parameter, it would make a difference of about 2 °c at 100 °c. So for best res...
by mstrens
Sun Apr 30, 2017 3:38 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

I checked again the formula (based on documentation on the web) and it seems me OK. Still I got some thermistors from aliexpress and I made a test. My thermistors where given as 100k with Beta 3950. When I measure the resistance with an ohmmeter I get - 100 k at 25 °c (OK) - 7 k at 100 °c (boiling w...
by mstrens
Mon Apr 24, 2017 6:03 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

I have no feed back on accuracy but I expect that good results should be achieved when the resistor is selected in order to get about Vcc/2 on arduino pin for the expected temperature. Do not expect an accuracy of 1°C. I think that there are some tolerances on NTC, that the temperature of NTC is not...
by mstrens
Mon Apr 24, 2017 5:35 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

indeed , if you have #define REFERENCE_VOLTAGE 5026 then you should use scale 1000*1023/5026 = 203.54 If #define REFERENCE_VOLTAGE is set as comment, then oXs supposes that Vcc = 5000. If you only measures NTC, in fact the value for reference voltage does not matter because arduino ADC will return t...
by mstrens
Mon Apr 24, 2017 4:39 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

About resistors, the doc says * If no divider is used for some voltage, set both resistors to 0 (zero) and the config #define RESISTOR_TO_GROUND 36 , 20 , 0 , 0 , 0 , 0 // set value to 0 when no divider is used for a voltage; can contains decimals #define RESISTOR_TO_VOLTAGE 670 , 100.1 , 200 , 39 ,...
by mstrens
Mon Apr 24, 2017 3:48 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

jhsa wrote:
Mon Apr 24, 2017 2:45 pm
Also, for sending the temperature to the radio (HUB protocol), do I need to configure a field, or is this one of the default fields??

Thanks

João
Hou need to configure it. There is no default for voltages (and derived measurements)
by mstrens
Mon Apr 24, 2017 3:46 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

In my opinion the voltage offset should also be in the basic config.h file, along with scale voltage. Question, for the NTC, using VOLT_5, shall I set both resistor to voltage and to ground with a value of "0 (zero)?? Thanks João The doc gives already the reply I think * Therefore, in section 6.1 a...
by mstrens
Mon Apr 24, 2017 6:23 am
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 380
Views: 20888

Re: New beta version of openXsensor (=openXvario)

Ok, this is the datasheet of the Thermistor I bought. It is a 3950 with a resistance of 100K at 25ºC. The temperature range is -30ºC to 270ºC, so what temperature must be inserted in the config file? the temperature range I need to measure is around 110 or 120ºC if the engine is not overheating, so...

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