|Surveyor Robotics Journal|
Mon, 31 Mar 2008
2.5Mbps test firmware for Matchport & SRV-1 Blackfin
We have test build of firmware from Lantronix which enables us to run the SRV-1 Blackfin with the Matchport at 2.5Mbps. This is a special build that is available only to SRV-1 users, and all support for this version of firmware needs to go through Surveyor, not Lantronix.
Configuration instructions are found here -
Tue, 25 Mar 2008
3.6mm f2.0 lens is now standard with SRV-1 Blackfin camera
We have made a small change in the standard configuration of the SRV-1 Blackfin camera board. The standard lens is now the 3.6mm f2.0 previously offered as an option, replacing the 6.3mm f3.2 lens that originally shipped. The 3.6mm is a very nice lens, with much better light gathering than the 6.3mm.
We are still offering the 2.2mm f2.5 wide angle lens as an option, combined with a right angle adapter to lay the OV9655 camera module parallel to the Blackfin processor card.
Mon, 24 Mar 2008
YARB 1.0 web page; perhaps some blimp kits in the future
To chart our robotic blimp development, there's now a web page devoted to YARB 1.0 (and successors), which includes some links to other interesting blimp sites.
There has been a fair amount of interest in this project, so we are starting to give some thought to offering a blimp kit to SRV-1 users. While we will continue to provide complete DIY information for low cost solutions, our current concept is to standardize on a somewhat higher-end platform with brushless motors and shrouds for the propellors. We're talking with a few potential suppliers, and will post additional info when available. Please send an email to email@example.com if you have an active interest in this project.
Tue, 18 Mar 2008
robotic blimp (YARB 1.0) update - sensors added
The blimp now have some additional sensors - a pair of Maxbotics EZ0 ultrasonic ranging modules and a Honeywell HMC6532 I2C compass. Also, the camera module now points downward about 30-degrees via a simple extender. The camera angle is pretty good now - the wide angle lens has a field-of-view of approx 120-degrees, so the bottom of the frame captures the scenary almost directly below.
At the moment, the sensor data is unfiltered, which allows us to get an idea of how much variation there might be. The ultrasonic data is pretty solid - the forward looking readings bounce around a bit, but the download readings are fairly consistent. However, I think we will change to a narrower beam module - probably the EZ1. Also, it would be nice to have a couple of side-looking modules to enable some degree of mapping capability.
The compass is less consistent, and it turns out that we're getting magnetic field interference from the motors when they are running. At the time I recorded the video clip below, I wasn't paying attention to the readings, but subsequent tests show that the readings are varying by as much as 15-degrees when the motors are powered. Either we will have to move the compass, or add some compensation in software.
Here's a snapshot of the gondola with the additional sensors -
The plan is to make changes in the sensors to clean up the data, and then to write a script using the onboard C interpreter to let the blimp wander around on its own, perhaps following a course based on heading. After that, we will add some logic to use the camera to lock onto an object and follow it around while maintaining altitude and avoiding collision - that will be a bit more challenging.
Here's some video captured from yesterday's test session. The caption overlay shows heading, forward distance and height above ground in inches.
Fri, 14 Mar 2008
YARB 1.0 (Yet Another Robotic Blimp) - first untethered flight
In my never-ending quest to defy gravity with the SRV-1 Blackfin, I installed the camera board and radio on a 66-inch helium blimp (ordered without their motor controller for a $100 savings) - interfacing the H-bridge on the SRV-1 combo radio/motor board directly to the two prop motors and one of the Blackfin's timer channels to the servo which vectors the prop thrust.
Here's SRV1Console with some different buttons that control the vectoring of the props and invert the video (the Blackfin board is suspended upside-down from the blimp gondola).
Using SRV1Console's archiving feature, I captured the video feed while piloting the blimp around the hallway and front room from my office. The blimp is surprisingly easy to pilot - this was my first attempt, and I didn't break anything, though there were some close encounters. The camera's a bit out of focus in the following video and the afternoon light washes out the scene somewhat, but you get the general idea.
Next step is to add ultrasonic sensors and a compass in order to start programming some autonomous exploration. This promises to be a very interesting project.
Wed, 05 Mar 2008
new test version of SRV-1 Blackfin firmware
A new test build of firmware has been posted, as discussed on the robot forum -
and posted to SVN at
The following changes/additions to srv-blackfin-022608 are included in this test version -