To be honest the Meade Autostar is better suited for tracking slow moving deep space objects instead of that which is considered more “local.” At least I can only assume it to be true as likewise I have yet to have success with the unit in the former arena. However the hardware is there: two-axis motor control with positional-encoder feedback, all via UART. The problem is, however, that the hardware interface is via a UART to a controller that is well documented to have buffering issues which ultimately leads to processor hangs and motor runaway.

More problematic is that there are only a few speed settings available via the uart; FAST! slooow, stop, reverse time-travel. The video below shows attempt at putting aircraft in track via a simple PI loop. The tracker attempt to lock, overshoots the target then hangs. Subsequent attempts to bring the target back into track succeed temporarily and ultimately results in a runaway gimbal.

The next step is to open the Autostar, tap into the DC motor wiring, and provide a nice dynamic range of control speeds via the Amani GT and an H-Bridge PMOD. The UART connection will be maintained for positional encoder data.

It should be noted the control-loop bandwidth will then be limited by the Arduino/Nootripics assembly. While the video experimenter is a fantastic proof-of-concept tool, the design will eventually be migrated to an FPGA-based system where data can be collected and processed in real-time and passed to the host machine via ethernet. Moreover the control-loop itself will reside in the electronics package; the host PC will only provide a user control interface and data display.

Open Autostar picture courtesy of RobRoy.

Happily, the Amani F1 is now in Alpha testing, the Beta test will be available to the public in relatively short order. If you would like to be part of the Alpha testing process, you are more than welcome to join, just email me to discuss the details.

Based on the EP1C3, the F1 will feature 2900 LE’s, 65 user I/O, and 7.5KB of user ram. Of course the standard Arduino, PMOD, and ASM carrier headers will be provided for additional RAM or other peripheral devices.

The Amani F1 is intended to be an entry-level FPGA development system, compatible with the Arduino. Subsequent Amani F-series boards are in the works, with more horsepower and will diverge from the traditional Arduino form factor. Stay tuned!

Featuring two CY7C1049DV33 4MBIT SRAM ICs featuring parallel interfaces for transfers up to 10ns. This daughter card also features its own regulator section, as a stuffing option, but is not required. When viewing the schematic, “DNI” indicates “Do Not Install.”

Feel free to download the Eagle files, submit to your favorite PCB manufacturer, and share your results!

Now I should state here, due to legal reasons, I have no intention of tracking the aircraft via radio waves. Instead I would like to test a video tracking system, which would augment a radar when the target object is low enough in elevation to cause multi-path issues for the radar. The cheapest and fastest path-forward was to utilize the Video Experimenter Board from Nootropic Design.

The electronics package consists of the Nootropic shield interfaced with and Arduino. To control the telescope positioner, the electronics package must communicate with the Autostar via RS232. An Amani GT is used to bridge between the Arduino UART and a Digilent Pmod232.

The Amani is also being used to handle an issue I am having with the video shield/Arduino stopping the video tracking arbitrarily. Serving as a watchdog, the Amani looks for a heartbeat signal and resets the Arduino when loss of heartbeat is detected.

Of course this configuration is just a method of rapid prototyping, for proof-of-concept and experimentation. The VTE issue must be ironed out eventually, however to get the tracking algorithm development going the Amani-reset will serve as a patch in the short-term.

Progress thus far has involved sitting the unit in the window and observing the video tracker’s ability to resolve and track aircraft while I steer the gimbal manually. With minor code revisions to the sketch provided at Nootripic Design, I was able to develop an error vector, seen below, which will serve as the input error to the tracking loop.

Currently I am ironing out the Autostar commands I found online, some if not most of which do not seem to work. If anything I’ll need to sniff the comms between the Astrofinder software on the PC and the Autostar. It should be noted that the PC software is not involved in this project and is just used for troubleshooting and communications study. A PC will be included in this system to provide graphical data to the user as well as a general control interface. The biggest issue I have is not being able to control speed. If necessary I’ll open the gimbal itself, cut into the motor controllers, and take control via the electronics unit.

I do have feed back from the positioner in the form of encoder counts, which is vital for closing the tracking loop. Currently I use the building across the way for boresiting the unit and calibrating the encoders.

The Meade ETX-60AT itself is a beginner’s telescope, better suited for terrestrial viewing. As it is integrated into the controller base, I cannot remove it without compromising the internal optics, thus it serves as platform for the camera to piggy-back on. It does open possibilities of integrating the telescope into the system, for distant-object tracking.

Even more interesting, and a definite DO NOT ATTEMPT, would be to integrate a laser range-finding system into the telescope while the camera provides the video tracking. This solution would provide fully-integrated TSPI data for under $400.

Check back for progress and project documentation.

-Eric

The video is an excellent primer for not only using the new AmaniGTX, but all the Amani derivatives and the Quartus II development tool.

The project source featured in the video is found here Simply unzip the project file in to the Altera project directory of choice and follow along with the video!

Use this guide when you are writing an Arduino sketch and need to know how Arduino PIN A on PORT X connects to the seated Amani Shield PIN B on the same port.

“The Amani64 is used for PWM RGB output and controlling the 8 leds. The Arduino’s SPI library is used for communicating the duty cycle and led settings to the Amani64.

Arduino/breadboard mount, RGB led, red leds and patch wires are from Arduino inventor’s kit.”

More info will be presented when made available.

The tutorial series can be brought up manually via your browser (you fill in the X’s):

C:/altera/11.XspX/quartus/common/help/tutorial/qtutorial.htm

The Amani GTX is a rapid-prototyping tool based on programmable-logic technology. At its core is the Altera MAXII EPM240 CPLD. As you progress through the class you will become more familiar with programmable logic, CPLD’s, and FPGA’s, and their myriad of applications.

The Amani GTX, along with its predecessors the 64 and GT, was designed to interface with the popular Arduino, , an AVR-based microcontroller platform that you will become familiar with as you progress through your studies. The Amani line was also designed to interface with the Digilent PMOD Interface Boards, application-specific I/O modules featuring Ethernet, WiFi, SC Cards, Joysticks, and more!

The Amani GTX also brings two new features to the Amani line of development tools. The first being integrated USB-based JTAG In-System Programming. The second feature includes an embedded Microchip PIC microcontroller for added functionality. With it you can create a USB-based UART to the CPLD, an embedded controller that interfaces via I2C, or something completely of your own creation.

Follow this link to pre-order your Amani GTX laboratory kit for this semester. Included in the kit is the MODsevseg, featuring a four-digit seven-segment display as well as four push-buttons for a user-interface to your Amani GTX. The kits are not yet available, so this is pre-order only.

Good luck this semester!

-Eric
www.amani64.com

Using the PicKit3 and a modified version of the USB-Blaster firmware by Satoshi of SA89A.net, (no, not the inventor of Bitcoin), the bitJTAG was programmed successfully and tested versus various Amani CPLD Shields and firmwares.

The bitJTAG can also be used as a PIC18F14K50 development kit. Get started programming USB by going through the exercises in the Low Pin Count USB Development Kit Guide with the bitJTAG development kit. Then reload the JTAG firmware and continue your Altera CPLD and FPGA development.

The bitJTAG is currently in Beta test and is available here. Design files and firmware posted very soon.