$ 100 car telemetry
It turned out that I have been interested in cars and motor sports for a long time, but my main work is directly related to the development of mobile platforms - and I have always been interested in the possibilities for connecting technologies from these different worlds. Fortunately, the last time for this has become much more opportunities. In this post I want to briefly share my experience with automotive telemetry.
Professional racing teams have been familiar with this topic for a long time and, as a rule, install very expensive recording systems (and sometimes live transmissions) of telemetry. Lovers usually do not want to spend such money, and it makes no sense. Below - about how cheap and cheerful to solve this problem.
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Many people know that modern cars have diagnostic connectors, to which dealer scanners are usually connected to troubleshoot various components; they are usually called obd-2. In addition to the service function, various data on the condition of the vehicle can also be obtained in real time via this data bus, such as engine speed, speed, boost pressure, coolant temperature, throttle position, etc. This data can be “obtained” from the vehicle by connecting a device to the connector that decodes these signals and converts them into symbols understandable for the computer. If such a device is equipped with a Bluetooth transmitter, then this data can later be transferred wirelessly to a laptop or smartphone. These adapters are surprisingly inexpensive, ranging in price from 12 to 20 dollars they can be ordered on eBay. I used this adapter here .
Smartphones based on the Android OS (and, unfortunately, the iPhone doesn’t fit at all — it simply doesn’t allow you to work with such devices via Bluetooth) to receive and process data. There are many Android applications that allow you to display, save and analyze data from the on-board computer of the car. Two of the most functional applications with which I experimented - Torque Pro and aLapRecorder HD , which will be discussed later.
In addition to the parameters of the car, full telemetry should also include data from the GPS receiver - coordinates, speed, acceleration of the car. Standard GPS receivers embedded in smartphones are not suitable for racing telemetry - they update data too rarely, no more than once a second. The track (trajectory) from such points will be broken and hardly useful. Therefore, we use an external GPS receiver that provides GPS data 10 times per second, for example, QStarz BT 818 XT . It can also be connected to an Android smartphone.
In addition to OBD-2 and GPS, the smartphone itself has a number of sensors, information from which can be useful for telemetry - it is an accelerometer (acceleration sensor along three axes), a compass, a gyroscope, and of course a camera for recording video.
Collecting all this data, synchronizing it in time, showing and saving is not an easy task. Therefore, it is not surprising that programs that perform such functions cost money, usually from $ 5 to $ 10. However, compared to professional telemetry systems, it is very, very inexpensive.
In addition to the above, you will also need a car charger with a USB output and a phone holder. To find a good holder that minimizes vibrations is a separate task, I have not yet succeeded.
A set of such equipment and programs allows you to save and view telemetry, if desired, in combination with onboard video, and export it to a computer for further analysis.
It can also be used for amateur karting races, as a tool for comparing speeds or maintaining individual timings.
Another potentially interesting example is the use of such a kit for transmitting telemetry to a computer in real time on a ring road. Such a project is currently being actively developed, those who wish can pay attention to the free WifiLapper application in the Android application store; project website is here .
The data saved in text formats can then be imported into professional telemetry analysis software (AIM Race Studio, GEMS Data Analysis), or in Excel in the simplest case, to plot the dependencies of the parameters of interest.
Unfortunately, the described option of receiving telemetry is hardly suitable for professional ring or rally teams, for several reasons:
- you need three pieces of equipment (telephone, OBD-2 adapter, GPS), for all you need power and mount
- programs for the phone need to be turned on and configured, they cannot be started and stopped with one button - as is usually required in sports
- the system is far from 100% reliable due to the large number of components, the factor of wireless communication, errors in programs
However, for fans of such an opportunity to trace the parameters of the car, as well as see their actions and analyze the errors can be really useful. I would also like to add that there are already a lot of applications for working with such equipment, and even the listed programs provide a lot of different possibilities - read the descriptions of the programs, watch the video and surely you will also be interested in this topic!
Once again, briefly about what you need to have for the realization of the described purpose:
- modern Android smartphone (from $ 200)
- Bluetooth OBD-2 adapter on ELM-327 chip ($ 15)
- Bluetooth 10 Hz GPS, for example QStarz BT-818XT ($ 80)
- Program aLapRecorder HD (52 UAH) or Torque Pro ($ 5) with the plug-in Track Recorder
- USB charger and phone holder (optional)
Equipment can be purchased and ordered by regular mail; usually within a month the parcels arrive.
In conclusion, links to several videos that I recorded as part of testing aLapHD and Torque Pro applications. I am pleased to answer questions on this topic :)
Professional racing teams have been familiar with this topic for a long time and, as a rule, install very expensive recording systems (and sometimes live transmissions) of telemetry. Lovers usually do not want to spend such money, and it makes no sense. Below - about how cheap and cheerful to solve this problem.
')
Many people know that modern cars have diagnostic connectors, to which dealer scanners are usually connected to troubleshoot various components; they are usually called obd-2. In addition to the service function, various data on the condition of the vehicle can also be obtained in real time via this data bus, such as engine speed, speed, boost pressure, coolant temperature, throttle position, etc. This data can be “obtained” from the vehicle by connecting a device to the connector that decodes these signals and converts them into symbols understandable for the computer. If such a device is equipped with a Bluetooth transmitter, then this data can later be transferred wirelessly to a laptop or smartphone. These adapters are surprisingly inexpensive, ranging in price from 12 to 20 dollars they can be ordered on eBay. I used this adapter here .
Smartphones based on the Android OS (and, unfortunately, the iPhone doesn’t fit at all — it simply doesn’t allow you to work with such devices via Bluetooth) to receive and process data. There are many Android applications that allow you to display, save and analyze data from the on-board computer of the car. Two of the most functional applications with which I experimented - Torque Pro and aLapRecorder HD , which will be discussed later.
In addition to the parameters of the car, full telemetry should also include data from the GPS receiver - coordinates, speed, acceleration of the car. Standard GPS receivers embedded in smartphones are not suitable for racing telemetry - they update data too rarely, no more than once a second. The track (trajectory) from such points will be broken and hardly useful. Therefore, we use an external GPS receiver that provides GPS data 10 times per second, for example, QStarz BT 818 XT . It can also be connected to an Android smartphone.
In addition to OBD-2 and GPS, the smartphone itself has a number of sensors, information from which can be useful for telemetry - it is an accelerometer (acceleration sensor along three axes), a compass, a gyroscope, and of course a camera for recording video.
Collecting all this data, synchronizing it in time, showing and saving is not an easy task. Therefore, it is not surprising that programs that perform such functions cost money, usually from $ 5 to $ 10. However, compared to professional telemetry systems, it is very, very inexpensive.
In addition to the above, you will also need a car charger with a USB output and a phone holder. To find a good holder that minimizes vibrations is a separate task, I have not yet succeeded.
A set of such equipment and programs allows you to save and view telemetry, if desired, in combination with onboard video, and export it to a computer for further analysis.
It can also be used for amateur karting races, as a tool for comparing speeds or maintaining individual timings.
Another potentially interesting example is the use of such a kit for transmitting telemetry to a computer in real time on a ring road. Such a project is currently being actively developed, those who wish can pay attention to the free WifiLapper application in the Android application store; project website is here .
The data saved in text formats can then be imported into professional telemetry analysis software (AIM Race Studio, GEMS Data Analysis), or in Excel in the simplest case, to plot the dependencies of the parameters of interest.
Unfortunately, the described option of receiving telemetry is hardly suitable for professional ring or rally teams, for several reasons:
- you need three pieces of equipment (telephone, OBD-2 adapter, GPS), for all you need power and mount
- programs for the phone need to be turned on and configured, they cannot be started and stopped with one button - as is usually required in sports
- the system is far from 100% reliable due to the large number of components, the factor of wireless communication, errors in programs
However, for fans of such an opportunity to trace the parameters of the car, as well as see their actions and analyze the errors can be really useful. I would also like to add that there are already a lot of applications for working with such equipment, and even the listed programs provide a lot of different possibilities - read the descriptions of the programs, watch the video and surely you will also be interested in this topic!
Once again, briefly about what you need to have for the realization of the described purpose:
- modern Android smartphone (from $ 200)
- Bluetooth OBD-2 adapter on ELM-327 chip ($ 15)
- Bluetooth 10 Hz GPS, for example QStarz BT-818XT ($ 80)
- Program aLapRecorder HD (52 UAH) or Torque Pro ($ 5) with the plug-in Track Recorder
- USB charger and phone holder (optional)
Equipment can be purchased and ordered by regular mail; usually within a month the parcels arrive.
In conclusion, links to several videos that I recorded as part of testing aLapHD and Torque Pro applications. I am pleased to answer questions on this topic :)
Source: https://habr.com/ru/post/156841/
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