This week I take a look at the Cypress Analog Co Processor Kit. The official website is at http://www.cypress.com/products/psoc-analog-coprocessor and in my video, I take a look at the PSOC Kit as well as the PSOC Creator Software.
A sensor doesn’t necessarily mean sight. Some times a sensor is able to pick up much more information like temperature, light, color, velocity, acceleration, inclination, altitude, depth, pressure etc. Depending upon the quantity to be measured and the environment where it will be measured, the sensors will vary. The basic principle however remain the same. Balanced whetstone, conversion techniques etc all are used even in the most advanced sensors. I won’t go into the history of things since I expect that my readers have already read the books. I will however explain some basics and assembly of sensors at a more practical level.
A robot is not necessarily a machine with arms or legs or even wheels. If the robot is a stationary machine as in case of robots like arm(welding and assembly line) robots, then the power supply is usually as simple as having transformers or SMPS etc. then using regulators for supplying the required currents.
If however the robot is a mobile autonomous robot, then we need to consider batteries. There are various types of batteries each with their own pros and cons. eg. Lead acid batts are longer lasting but are really heavy etc. Here is some info. as taken from the robot builder’s bonanza book.
Zinc batteries are the staple of the battery industry and are often referred to simply as “flashlight” cells. The chemical makeup of zinc batteries takes two forms: carbon zinc and zinc chloride. Carbon zinc, or “regular-duty,” batteries die out the quickest and are unsuited to robotic applications. Zinc chloride, or “heavy-duty,” batteries provide a little more power than regular carbon zinc cells and last 25 to 50 percent longer. Despite the added energy, zinc chloride batteries are also unsuitable for most robotics applications. Both carbon zinc and zinc chloride batteries can be “rejuvenated” a few times after being drained. See the section “Battery Recharging” later in the chapter for more information on recharging batteries. Zinc batteries are available in all the standard flashlight (D, C, A, AA, and AAA) and lantern battery sizes.
Alkaline cells use a special alkaline manganese dioxide formula that lasts up to 800 percent longer than carbon zinc batteries. The actual increase in life expectancy ranges from about 300 percent to 800 percent, depending on the application. In robotics, where the batteries are driving motors, solenoids, and electronics, the average increase is a reasonable 450 to 550 percent.
When you think “rechargeable battery,” you undoubtedly think nickel-cadmium—or “Ni-Cad” for short. Ni-Cads aren’t the only battery specifically engineered to be recharged, but they are among the least expensive and easiest to get. Ni-Cads are ideal for most all robotics applications.
NICKEL METAL HYDRIDE
Nickel metal hydride (NiMH) batteries represent one of the best of the affordable rechargeable battery technologies. NiMH batteries can be recharged 400 or more times and have a low internal resistance, so they can deliver high amounts of current (read more about internal resistance and current in “Battery Ratings,” later in the chapter). Nickel metal hydride batteries are about the same size and weight as Ni-Cads, but they deliver about 50 percent more operating juice than Ni-Cads. In fact, NiMH batteries work best when they are used in very high current situations. Unlike Ni-Cads, NiMH batteries do not exhibit any memory effect, nor do they contain cadmium, a highly toxic material.
While NiMH batteries are discharging, especially at high currents, they can get quite hot. You should consider this when you place the batteries in your robot. If the NiMH pack will be pressed into high-current service, be sure it is located away from any components that may be affected by the heat. This includes any control circuitry or the microcontroller.
A lot more material is available on the internet about batteries and battery care and recharging. From my experience however this is what I have to share.
For very small and short lived projects, you might consider simply using a step down transformer and using a regulator with it. The adapter is reuable and is cheap and is easy to use and store.
For mid-sized projects with time limits, I recomend using zinc or alkaline batteries. They are cheap and easily available and give you mobility.
For long lived projects that don’t require immediate ‘put the battery on the board’, consider going for a 12V lead acid battery. They dont need frequent recharges and give you mobility more or less.
For more permanently mobile battery solutions that I used, I used rechargable Ni-MH batts. Lots of em. clubbed with regulators. I bought them in bulk and I usually have one pair in the recharger all the time cause of my usage.
I simply put two packs together and on a small PCB put an 7805 with the necessary components and a whole lot of connectors. And this is what I use.
I am doing a repeat of a a series I published on my site a few years back. This series most of the topics of DIY robots and related topics. Feedback is encouraged because I need to know what everyone wants to read. 🙂
The poorman’s robotics kit is the basic modules approach for a hoybist or student to start with robotics projects. In India resources like Multilayer PCBs, high-end micrcontrollers etc are not available everywhere. Lego Mindstorms does provide robotics materials but in India, instruments like CROs and microcontrollers are not very common.
So what is the purpose of this documents?
The answer is that when a student or interested individual goes to buy things for experimentation, he will know exactly what they are getting into and what are the basic components needed. I am not yet commercially selling such kits to individuals, but different versions of this kit are available to students that undergo training by us. I am not promising support to anyone, but the email ID of my friends and myself are given in the contacts section so you may email us doubts and questions and we will try our best to help you out.
I was involved briefly in some training projects in Pune, India. The students did a great jobm but while they were leaving, I could not help but think that some activities become restricted due to lack of resources like programmers. Since I have been experimenting with electronics for the past 15 years(since my 3rd grade in 1993) I have tried to add some cost effective solutions to robotics design and some of my own ideas on how to hack-up toys etc to get the electronics and mechanical parts needed. Where to find all that is in your hands now.
The Building Blocks
I wont start with table-top kits and all that because I assume you have worked with them at your colleges.
Q. Why do we have table-top kits since they are not the hardware that are going to be used in actual robots?
A. It is correct that the standard ‘kits’ are not going to be used in practical projects. These are not exactly developement tools, but rather learning tools. Imagine that you have to make a simple robot. After you freeze your specifications, you assemble your hardware and then write your software. When you put them together and they dont work where is the problem? Since both hardware and software are untested, how do you know where to start debugging? If however, you have a standard kit that you are sure works, then you can test the software and if the same working workware does not work on your hardware, you know where the fault is.
For any basic practical robotics experiment there are some fundamental modules necessary. These being:
Processor or Controller or Control Logic: This is the brain of your robot and has the algorithm on it. It is responsible for controlling the activities of the robot like reading from sensors, decision making and controlling the actuators etc.
The Power Supply: Other than the obvious, the power supply is expected to produced all required voltage levels and regulated/unregulated outputs that may be mutually isolated.
Sensors: The eyes of the robot- For any real-time task, the robot need inputs that may be regarding objects, temperature, voltage levels and even position. Advanced robots include electronic compases and gyros and accelerometers etc.
The Chassis: If your robot is needed to move around, it needs wheels. If it is an arm robot, then it needs the physical arm joints etc. A physical structure that will include the wheels, grippers, motors, gears etc.
Drivers: The Processor or Controller or Control Logic usually cannot supply enough to directly run motors etc. So transistors or FETS etc are used to drive them.
Programmer: To download the algorithm to microcontroller, or ROM or CPLD or FPGA.
Diagnostic Tools: Simple circuit that can be very useful
Communications: Sometime there is a need to connect to a robot.
I have made this kit in terms of modules. The modules can be connected to each other in different ways for different robots. I will be covering these in this series.