Data-logging and telemetry, open source projects
Continuing with the theme of the previous post where we’ve seen COTS data loggers, here I will list all the open source projects I’ve found during my research. Those projects are a good starting point because most of them offer their source code, and even the schematics.
One of the most full featured open source data loggers I found out there is RaceCapture/Pro by Autosport Labs. Here, their Indiegogo campaign promo:
Race Capture Pro isn’t just a powerful data acquisition and control system; It’s an Open Source Hardware and Software project. We will open the design for your inspection, tweaking, and customization. No secret file formats and no expensive, proprietary add-ons. Frankly, we think this is silly and it’s time that a project like this exists to serve the enthusiasts first. And we’re excited to share it and see where we all can take it together!
That just sounds great. Let’s take a look at the features:
- 7 analog input channels
- 3 frequency input channels
- 4 analog or frequency output (PWM) channels
- 3 configurable digital channels, settable for input or output
- 4 Axis Accelerometer: 3 channel accelerometer module plus Z-axis gyro
- 10Hz GPS module input
- Auxiliary Serial Port
- Digital expansion port
- SD Memory card slot for data acquisition
- 48MHz 32 bit ARM processor
Nothing to envy a professional data-logger. But no data-logger is complete without a companion analysis software. The boys at Autosport Labs have developed Race Analyzer which reads simple comma-separated value (CSV), no secret nor complex file format; thus, we can take advantage of the already-developed analysis tools for our own projects and/or adapt it to our own needs.
Another sort-of open source car data-logger is the Vehicle Telemetry Platform I already mentioned in a previous post. In this project they get most of the data from the ECU using an OBD-II adapter, combine this data with a GPS module and save all the values in plain CSV on a memory stick. They include a simple script that converts the raw data into KML, which can the be visualized in Google Earth as shown in Figure 1.
Another project to take into account is ArduPilot, an open source UAV platform. As autonomous aerial vehicles need accurate positioning, the project can give us an insight on what components are best suited for this task (GPS modules, accelerometers, gyros…). Furthermore, autonomous vehicles are usually remotely connected to a base station, hence can serve as a guide on RF modules, which play an important role in telemetry.
By combining those projects one can end up with a real bad-ass telemetry and data-logging system.