There is a green room backstage with two stage entrances just off of the theater. It contains two large countertops with mirrors, as well as a sink. Monitors provide an audio feed from the theatre. The green room also provides a route to the restrooms and water fountains without passing through the theatre.
As a blackbox-style theatre, there is not a dedicated stage, which means the addition of more chairs will reduce the available space for a performance or presentation. Up to two rows of chairs can be placed on risers to create a stadium-seating feel.
Chisel BlackBoxes are used to instantiate externally defined modules. This construct is usefulfor hardware constructs that cannot be described in Chisel and for connecting to FPGA or other IP not defined in Chisel.
Unlike Module, BlackBox has no implicit clock and reset.BlackBox's clock and reset ports must be explicitly declared and connected to input signals.Ports declared in the IO Bundle will be generated with the requested name (ie. no preceding io_).
Chisel provides the following ways of delivering the code underlying the blackbox. Consider the following blackbox thatadds two real numbers together. The numbers are represented in chisel3 as 64-bit unsigned integers.
In order to deliver the verilog snippet above to the backend simulator, chisel3 provides the following tools based on the chisel/firrtl annotation system. Add the trait HasBlackBoxResource to the declaration, and then call a function in the body to say where the system can find the verilog. The Module now looks like
The verilog snippet above gets put into a resource file names real_math.v. What is a resource file? It comes froma java convention of keeping files in a project that are automatically included in library distributions. In a typicalChisel project, see chisel-template, this would be a directory in thesource hierarchy: src/main/resources/real_math.v.
This mechanism of delivering verilog content to the testing backends is implemented via chisel/firrtl annotations. Thetwo methods, inline and resource, are two kinds of annotations that are created via the setInline andsetResource methods calls. Those annotations are passed through to the chisel-testers which in turn passes themon to firrtl. The default firrtl verilog compilers have a pass that detects the annotations and moves the files orinline test into the build directory. For each unique file added, the transform adds a line to a fileblack_box_verilog_files.f, this file is added to the command line constructed for verilator or vcs to inform them whereto look.The dsptools project is a good example of using this feature to build a realnumber simulation tester based on black boxes.
In this tutorial I will explain how to record Blackbox logs, the ins and outs of Blackbox Explorer, and show you some examples on how to interpret the graphs for basic tuning and troubleshooting of a Betaflight FPV drone.
Blackbox will start recording as soon as you arm, and it will stop when you disarm or when memory is full. Personally I prefer to start/stop Blackbox whenever I want using a switch. You can do this in the Modes tab by assigning an AUX channel to Blackbox.
FC with onboard memory will only create separate log files after a power cycle, otherwise all logs are stored in the same file. Using SD card however, will save the logs in separate files when Blackbox is activated every time (e.g. disarm and arm) without power cycling the quad.
Finally, if during the same lipo, you have armed and disarmed your quad several times, the log will be divided into several parts. You will be able to access each of the flights made on the LiPo using the drop-down list at the top of the right column in Blackbox Explorer.
On the top left of the graph, you have a representation of the drone, it shows the current attitude and the outputs of the motors. On the top right you have the current stick inputs. These are overlays and you can turn them off if you want.
On the right hand column, you can select what traces and graphs you want to look at. On the bottom, there are 3 options above the Graph Setup button. You can use Expo to see traces with a bit higher fidelity, Smoothing to get rid of excessive vibration in the traces if you just interested in the average trend of the traces.
The best way to sync is to find the spot where you do the first roll or flip. Press the M key (marker) in the log where your stick begin to move to do a roll/flip. Then scroll through your video until you see the moment you start to flip/roll, then press ALT + M, it will sync the log and video together.
To focus on a specific group of traces, click on name of the group. It will remove all the other groups of graph. To go back to the original view, just press 0 on your keyboard (back to the original workspace).
This is how traces look like in a roll/flip. The cursor is in the center of the roll, and in the legend, you can see Gyro is reporting 703 deg/s, which corresponds to the maximum rotational velocity set in the Rates.
When P is too high (or D is too low), P will overshoot or even oscillate in worse cases as you move the stick, and those wiggles can get into the gyro trace. To fix it, you can increase D to dampen it, or decrease P.
Feedforward can help gyro track setpoint better, but too much Feedforward can cause it to overshoot. In this case you can see the gyro line moves before the setpoint, it actually causes P and D to move the opposite direction of the stick to try to slow down the gyro.
When hovering, one motor is working harder than the rest. This is usually an indication of an ESC or motor issue. try swapping around the motors. In this example, motor 1 clearly has issue, so after swapping the motors around, if the same motor still having issue, then the ESC is the culprit.
An ESC desync occurs when one of the motors stalls (stops spinning and thus stops producing thrust), prompting the drone to command that motor to spin harder, causing the motor signal to reach its maximum of 100%. Learn how to fix ESC desync here: -esc-desync/
Just had my drone fall out of the sky literally, I was cruising and then it started spinning and went down. Luckly I managed to recover it and now can use BB data for analysis. Blackbox shows that right before it starts spinning one of motors goes to zero output. Diagonal motor goes to 100% apparently one compensating the other. Am I safe to assume that my prop just fell off (and if so, which one, on the motor that goes to 0 or the one that goes to 100 trying to grasp thin air without a prop?) If not, what does it make sense to look for further?
Thank you for the quick reply. It was just as you suspected. The setting was at 800Hz. I have now increased to 1600Hz. 2000Hz I can not set (BMI270).
Thanks for the good support and all the info.
Yea I am planning to do some content on PIDtoolbox.
I still find it faster to tune quads by ears and looking at googles, then fine tune looking at blackbox. But if someone has no idea how to tune at all, PIDtoolbox is foolproof for sure.
The blackbox is a simulation, I do not think it is possible to write a backward for it. I attempted to call back() on the output of RNN directly giving the error as all the gradients, it failed the system.
The computation graph is built during the forward pass and is used in the backward pass to calculate the gradients.
If you are detaching some tensors from the graph, you would need to write the backward manually, as explained.
I am facing a similar problem. I apply RNN (LSTM/ or GRU or TFT) to generate driving signals, however, there is no label data(target signal) to calculate loss function directly. However, there is one-to-one relationship (pre-known with certain unknown noises) between the driving signals and the response signal. The response signal has target data to generate loss function.
I am wondering to applied decoder (another LSTM to model the relation-ship between driving signal and the response), however, this might increase the complexity (since the relationship between driving signal and the response is 90% known in advance).
Now I am learning the autograd of Pytorch, hoping that the parameters of RNN could be auto-corrected by the indirect loss function. I try to make the response signal to be (requires_grad=True), however, it does not update the model at all, since the loss keeps all the same during training.
I delete all state variables, and it can train successfully. However, It is necessary to pass this variable for response simulation.
For real experiments, this response simulation will be replaced by sensor signals. It is supposed to jump out this problem.
Separation of macros into blackbox ones and whitebox ones is a feature of Scala 2.11.x and Scala 2.12.x. The blackbox/whitebox separation is not supported in Scala 2.10.x. It is also not supported in macro paradise for Scala 2.10.x.
With macros becoming a part of the official Scala 2.10 release, programmers in research and industry have found creative ways of using macros to address all sorts of problems, far extending our original expectations.
In fact, macros became an important part of our ecosystem so quickly that just a couple of months after the release of Scala 2.10, when macros were introduced in experimental capacity, we had a Scala language team meeting and decided to standardize macros and make them a full-fledged feature of Scala by 2.12.
UPDATE It turned out that it was not that simple to stabilize macros by Scala 2.12. Our research into that has resulted in establishing a new metaprogramming foundation for Scala, called scala.meta, whose first beta is expected to be released simultaneously with Scala 2.12 and might later be included in future versions of Scala. In the meanwhile, Scala 2.12 is not going to see any changes to reflection and macros - everything is going to stay experimental as it was in Scala 2.10 and Scala 2.11, and no features are going to be removed. However, even though circumstances under which this document has been written have changed, the information still remains relevant, so please continue reading.
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