My FYP Idea

[yh88]

I am having an idea for my Final Year Project but not very sure it whether it fit my budget.

I would like to control a robot via the internet. For example, I will turn on my PC at home which is used to control the robot. Then, let's say I am in my office, I am capable to control the robot via the internet.The GUI would be web based. I saw some sample which is using a wireless router which is too costly for my project. So, I prefer not to use it.

Does my idea workable and is it going to cost a lot to me?
My budget is around RM500-RM700.

[ober]

depend on how you design your system. Your robot should be wireless controlled. If you want to use wireless router, you need to use WiFi at your robot, which is not cheap. If you want to use Bluetooth, the straight forward way is to have a computer at your home connecting to LAN and translate command or information to Bluetooth and your robot should have Bluetooth. The cost also come from the robot and controller, 500-600 is very tie budget.

Good luck.

[sich]

Yes, your idea is workable. Actually you can search for home automation system. I think you can find a lot of example and control method there. The difference is home automation system usually controls home appliances and for your case, you control a robot. I strongly believe future home automation system must include a robot too. So I take your idea positively

Generally this is the rough picture in my mind if you want a low-cost solution:

PC (remote) <--- Internet ---> PC (home) <--- Bluetooth/ZigBee/low freq RF ---> Robot

[yh88]

Thanks for the advice.
Due to the cost and time limitation, I think I have to eliminate some of the feature like control via internet.

For the wireless module, I think I can use RF for transmission because bluetooth module like Xbee/Zigbee are very high in cost. So, now my question is, is there any module available for the two way transmission in RF since I need to get feedback from my robot.

Or

I need to have two RF module with different frequency to support the two way transmission.

Transmission reliability:
I used the one-way transmission RF module before but sometimes the data transmission is not that good. Is there any way to improve its reliability and robustness(interrupt by other RF frequency)?

[robosang]

If you are using low cost RF module, that is the drawback you need to accept - Interference from other source. maybe you can lower down your communication rate. It should reduce the error rate.

[sich]

You can use some encoding techniques to reduce or even eliminate the interference. For example Manchester Encoding.

Lately, Cytron sent some engineers to witness the Robogamez 2009 in UNITEN. We talked to some UM students who participate in the game. They told us that one of their team is using the low-cost RF modules to control their combat robot wirelessly. Before they apply the encoding in the communication, they also encounter the same issue like what you are facing now. However, the problem is solved after applied encoding. We didn't ask them the type of encoding they use but practically they proved that it works!

[yh88]

Thanks for your info and I have found the proper encoder/decoder for the RF module.
For the decoder IC, there are two modes available which are momentary and latch. According to my understanding, the output of the latch mode encoder will remain the same until the next bits of data is received. The momentary mode should be the other way.

So, in order to control the robot, which mode i suppose to use? Let's say I want my robot to execute an action like blink the LED once a command is received. If I am using the latch mode the command received is repeating, so the LED will keep blinking? Is my statement correct? Or May be I can control it blinks once by using end command in the programming part while those action like (moving) without the end command.

Point it out if I am wrong.

[aurora]

Hi yh88,

You are right about the latching definition. The IC will send a constant output (high/low) interchangeable only when you change the signal (or more precisely, a pulse, due to the press and depress action). You just need to poll for the high signal from the IC to command your LED to blink. Alternately, you can use momentary mode, but you need to program your PIC to poll for pulse. Basically it's the same function, except you transfer it from the IC to your PIC.

For robot movement, you use the momentary mode. Poll high for action, low for non-action.

If you require high RF stability, additional channel, faster response, try the 2.4ghz module. Normally use by RC hobbyist in helicopter and airplane. You can find those in RC hobby shop, price start from RM150.

[yh88]

Hi yh88,

You are right about the latching definition. The IC will send a constant output (high/low) interchangeable only when you change the signal (or more precisely, a pulse, due to the press and depress action). You just need to poll for the high signal from the IC to command your LED to blink. Alternately, you can use momentary mode, but you need to program your PIC to poll for pulse. Basically it's the same function, except you transfer it from the IC to your PIC.

For robot movement, you use the momentary mode. Poll high for action, low for non-action.

If you require high RF stability, additional channel, faster response, try the 2.4ghz module. Normally use by RC hobbyist in helicopter and airplane. You can find those in RC hobby shop, price start from RM150.

Thanks for your information. 1 channel will do for me and the 2.4GHz that you mentioned is too much for my project. By the way, thank you.

[yh88]

I find out that the members in this forum are willing to help. So, I think i will post up my question and my project progress here. Actually my project will only start in the Jan 2010. Now, it is just under planning stage. Thanks for all the information.