Search found 1060 matches

by mstrens
Sat Jul 01, 2017 6:14 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: GPS sensor
Replies: 400
Views: 21204

Re: GPS sensor

At start up, oXs send a set of commands to GPS in order to force some wel defined configuration. It assumes that after reset the GPS uses the default setup (in order to accept the commands beng sent by oXs). I had to do it in this way because my first GPS board had a bad eeprom. I would recomend to ...
by mstrens
Sat Jul 01, 2017 5:36 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: GPS sensor
Replies: 400
Views: 21204

Re: GPS sensor

I had a short look at the code and I think that you have to try with a physical GPS sensor.
I expect that the buffer use in simulation does not contain the data that will simulate a fix.
by mstrens
Sat Jul 01, 2017 1:56 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: GPS sensor
Replies: 400
Views: 21204

Re: GPS sensor

oXs can send GPS data even if there is no baro sensor. In your config, you should keep this line as comment (as you are not using an ADS1115. #define ADS_MEASURE A0_TO_GND , A1_TO_GND , A2_TO_GND , ADS_OFF I suggest that you also try keeping the debug line as comment (#define DEBUG). Please note tha...
by mstrens
Thu Jun 29, 2017 6:37 am
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: Brainstorm: oXs as wing level indication system
Replies: 27
Views: 1264

Re: Brainstorm: oXs as wing level indication system

the 6050 is running his own code in order to provide the 3D orientation of the sensor. This code uses as well the gyro as the accelerometer informations. Gyros are good for quick changes but are known to drift over time. Accelerometers data are then used to realign the position. In order to achieve ...
by mstrens
Sun May 28, 2017 7:19 pm
Forum: OpenXVario - an open source vario supported by the open source firmwares!!
Topic: New beta version of openXsensor (=openXvario)
Replies: 385
Views: 23537

Re: New beta version of openXsensor (=openXvario)

When an ADS1115 is used, current version of oXs let send to Tx the (up to) 4 voltages being measured. It does not calculate each cell voltage nor the minimum. I expect that with openTx you can perform the calculations you ask for based on the 4 voltages. Perhaps you can do it using calculated fields...
by mstrens
Mon May 15, 2017 6:41 am
Forum: openTx
Topic: Help needed for a lua script.
Replies: 5
Views: 394

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: 394

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: 394

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: 303

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: 303

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: 385
Views: 23537

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: 385
Views: 23537

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: 385
Views: 23537

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: 385
Views: 23537

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: 385
Views: 23537

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: 385
Views: 23537

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: 385
Views: 23537

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: 385
Views: 23537

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: 385
Views: 23537

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: 385
Views: 23537

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: 385
Views: 23537

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: 385
Views: 23537

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: 385
Views: 23537

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: 385
Views: 23537

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: 385
Views: 23537

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: 385
Views: 23537

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: 385
Views: 23537

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: 385
Views: 23537

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...

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