Hi guys. I'm thinking of getting the ICD2 LE, programmer with in-circuit debugger capability. Microchip is having a 60% discount. The price after discount is about RM200+ including delivery. The usual price is RM400+.

Anyone interested to get one so that we could share the delivery cost?

This post has been edited by Aurora: Dec 7 2008, 10:33 PM

Hi guys. Not much thread count since the last time I visited. Out of blue, it appears on first page of hobbies forum

I am an electronic enthusiast here, a humble hobbyist though Don't know much about electronics actually, my background is mechanical. Did a robotic project back in my final year, and screw up the electronics part.

My main interest is in microcontroller and robotic. Currently relearning the microchip PIC programming (not at atmel fan here). Just started recently. Got a few lame LED running . Now working on RGB LED, typical control like fading, etc. and LCD control.

Nothing much in mind. Probably will try to do a simple calculator via the LCD, then move on the GLCD for graph plotting

Once got a hand on those then will only try get back into robotics.

You can build a spacecraft but dont know how to build a blinking circuit? jk

Try google for "RC circuit LED", or "555 Timer LED".

This is a typical final year project. I know there are people who are willing to get paid to do this project for you.

PIC16F873A is a microchip product, try download MPLAB from microchip website. It’s a free assembly software and compiler.

You should be doing your research, and generate your own source code…. No offense, but this is as much as I can help (unless I get paid if you want free info )

mikroC is a C compiler, using C language, not assembly. I am not familiar with mikroC codes, but generally it should be identical as other C compiler. I am using PIC C Compiler.

C is easier than assembly, why not use C?

I assume that your uni use mikroC product and programmer?

Have you found the answer you are looking for? There are a few types of battery available in the market, the most popular one are namely the Lipo and NiMH. Lipo are more expensive than NiMH, however they are lighter and provide better current output. Retail charger for Lipo are also much more expensive than NiMH. If you are looking for cheaper battery, I suggest you try the typical rechargeable battery (GP, Sanyo, Energizer). You would need 6 cells, 1 NiMH charger, which come to about RM100++.

There aren't any datasheet for battery (I have yet to come across any ) Unless you application is drawing high current, it should do fine. Estimation for rechargable battery duration = (mAh rating) / (mA drawed by circuit).

With 2000mAh battery, it would last you 1 hour for 2000mA circuit, or 2 hours for 1000mA circuit, and etc.

Actually, I am (just started) planning to build my own Lipo charger. Still doing some reading here and there.

Anyway, I am also looking for a suitable high current (10-15A) voltage regulator, from 7.2VDC to 6.0VDC. I have yet to find the right chip, or circuit. Any recommendation? Anyone?

This post has been edited by Aurora: May 8 2009, 11:23 PM

Where did you get the information that the RC rechargeable liftcycle is 30 to 50? Those are Li-ion/NiMH, shouldn't all their lifecycle standard? Which is 500-1000? Care to share the link?

I'm trying some linear regulator now, the low dropout type. With that, I'm still throwing some 12W of heat. Not that practical. I need those 10A to drive few motors I found this link High Current Regulator Supply using LM317.

I'm new to electric power, not aware of switching regulator, I'll start looking and see what I can get

Probably right. RC motor draws high Amp. But battery technology is pacing. The battery university link was written few years back. (No wonder I can't find any info on Lipo). Lipo technology has advanced since it was first introduced few years ago.

I have the LM317 (max 1A), and LM338 (max 5A) continuous application. The LM338 is in TO3 form as you described. I have not try it, my circuit is still not ready

I plan to use Lipo 7.2 VDC (at least 4000mAh) for my application, and would last me about 20-30 mins. A fully charge Lipo has 8.4V, which drop to 7.2V in 5-10 mins and stabilize. All I need is to stepdown the voltage to 6V for my motors, and another 5V for circuit and control.

Since my supply voltage is considerably low and stable, switching regulator looks pretty promising.

The circuit would draw about 100-200mA only, I'm using LM317 for that. Worst case I'll be using 2x LM338.

You have good link/resource for switching? I reading a few here and there

Typical lipo output voltage during operation is 3.7V per cell. For complete charging, it require 4.2V, and usually a complete charge would give 4.25V. Off the charger, it would generally gives 4.2V. Upon load, it would drop gradually to 3.7V on the first 10% of discharge/usage. Thereafter, it would maintain at 3.7V until it reach 30% before it start dipping.

For NiMH, 1.2V is typical output voltage, while complete charge is usually 1.25V.

I'm using 2 Lipo cells in series, so that is would give typical 7.4V and 8.4V off charger. I have take care of all major motor related issue I have consider pass transistor, but isn't that the result same as regulator? A lot of power and heat dissipation?

I'm digging into buck converter and SMPS. I notice that it is normally use for regulating 24V to 12V, mostly more than 50%. My application of 8.4V to 6.0V looks like peanuts only Hopefully it can handle.

This post has been edited by Aurora: May 9 2009, 06:23 PM

It depends how fast and how powerful you want your go kart to be. For faster acceleration, you'll need a stronger motor. Seems like you will need a motor rated for few hp to be competitive enough. 1 hp = 745.7 watt. You will need motor with rating of several thousand watts. Try ask in go-kart thread (if any )

---

Added on June 10, 2009, 10:45 pmI have reach the final stage of circuit prototyping, and will be moving on the the next step, which is PCB fabrication. Currently stuck on trace sizing. How wide should it be, for a 6v, 6A (typical) and 8A (peak) current? I googled around, and there are several version. I like to hear from someone who has experience it, if any.

Here's few sneak peek of the electronics:


The 2nd picture maybe familiar to some RC fan.

This post has been edited by Aurora: Jun 10 2009, 10:45 PM

How big of a sonal panel? There are shops at Jalan Pasar selling solar panel about the size of a wallet, I saw it last month. Not sure how much it cost. There are also some super big solar panel.

Good point.. Actually charging is more dangerous than draining. Never leave Lipo charging unattended, while draining from Lipo, not encourage to overdrain. As soon as there is sign that battery is running flat, charge it immediately.

Those ppl is RC forum knows better in Lipo handling, because they use it on expensive equipment! heli and plane bah...

I think the intention of the guide is to establish direct communication between hdd and PC only with a TTL-RS232 converter.

Anyway, you can connect the tx/rx directly to the hdd, provided you step down the voltage. This can be easily done with simple transistor circuit.

As for the communication between PIC and PC, you can use the circuit in your book, how to connect a MAX232 to your PIC. The circuit is common, you can't go wrong with that. You can get MAX232 chip in jalan pasar.

For starter, I think best if you leave out the hdd first. Try work on the communication between PC and PIC. Connect a few LED to your PIC, and try to send command via hyperterminal. Just relay the bits to the LED. Next try with few push buttons, and test if the PC received the signal from the PIC. One step at a time, it's easier to troubleshoot this way, especially when you are writing the software UART code.

To insert your code, used the {code}{/code} (Replace {} with [])

Yup, as the guide suggested, it was meant to connect directly from hdd to com port. Rewriting the entire code is just messy. Since com port can communicate directly via hyperterminal on XP, (which is sweet), just follow the guide and you won't be wrong. The only thing you need to figure out is to either buy the same converter (recommended), or you need to figure out the right chip and circuit. Try to look around for the circuit (check the chip datasheet in used for the said converter, and look for the application note). Try look around Perlis first. Just let me know if you can't find the chip there, I can buy for you, provided it's not urgent. (I usually go there once a month to pick up some component for my project)


Erm, aren't you suppose to do some research first before asking? Since it's FYP, some people are willing to do it for you, at a price of course. jk

Anyway, which stepper motor are you using? i.e. the rating, spec, etc. I think parallel port is phasing out slowly, not sure if the new motherboard still got or not. I trust that your PC still have it. There are abundance of for communicating using parallel port. Cause we don't know what is your level and application, I think best if you google first, find a nice guide that really suit your need, and try to read first. If you still can't understand, post here and we are glad to help.

Depends on your audio quality, a very simple song (i.e. bepper type, sound quality is like dinosour-age nokia 3310 ringtone) can be produce with just a programmable micro-controller, the smallest and cheapest one is probably around RM10 (check lelong.com.my), not much component require. But the chip is quite big la, you can't really get those small circuit like they sell in bookstore. If you want better quality, like MP3 (i.e. instrument with you singing the song).... That one more expensive, you need to get a MP3 encoder/decoder chip. Even I haven't play with that before. You can try google DIY MP3 circuit. This idea is best if you want to make a customize music box, cause the circuit+battery itself is just no sense to put onto a card...

Bro, FYP is meant to work by yourself le.... We can help on trouble-shooting, i.e. share with you which ingredient is the best to prepare the meal, but don't come and ask us to feed you le... Seriously, I'm also dead lazy to search for the literature on how to do it. Go google, and if you find some link that you can't understand, post here and we will guide you.


Any pin count will do, you don't need all the pins. But need to check the internal memory. I haven't write a music program file before, my guess is even the smallest size will do. Like tgrrr said, just engage the PWM, then change the duty factor and you can get your music already. See if I'm free to do a simple demo or not this weekend. First need to get a beeper/speaker, maybe steal from my PC casing.

Not familiar with ARM or ARC, not exactly a popular chip for hobbyist. How does it compare with other uC? Maybe will do a little google if had time. Sure like to play around with it, if the chip can be purchase over the counter.

I tried before DIY PCB etching up to 0.012", which turns out to be quite good, but that is for through-hole PCB. 0.010" should be achievable. Like what tgrrr say, aligning the pattern for the via can be a pain, well, unless you make the via thicker, so you have some tolerance in case it slips.

I haven't make my trip yet since my last post, been quite busy recently. If it is not urgent, I can check out for you. But you need to tell me exactly what chip are you looking for ah... How much is your budget? If it happen to be within your budget, you want me to quick grab for you?

Thanks for pointing out. I think ARM are quite high end chip, like use in mobile device. Anyway, you have any idea what IC/uC used to read camera module? I saw a cheap camera module in Sparkfun, and seems like 40mHz just barely able to read the camera module. I like to do something like wifi camera. Any suggestion? Maybe will get a cheap 2nd hand handphone with VGA camera, hack and see what they use inside.

e-fatty, nicotyne: I just saw this thread This guy has a lot of components for sale, maybe you can try ask him.

e-fatty: it was mention in the link that hdd Vss is only +3.3v, max232 chip is rated for 4.5-5.5v (typ. 5v). You need to take a look at max3221, and the application note, usually it will show you few circuit example to how to connect the chip.

tgrrr: Honestly, I don't know what I'm looking for. Camera module usually transmit in i2c, with other information available by the reading the rest of the pins. I read the datasheet, seems like need to write down a lot of code if I were to use uC. In case there is already a better solution... like a specific chip or module My target is to at least able to read, say 50x50 line out of the entire resolution (VGA or higher). I'm working on a project similar to line-following robot, but can't use the typical close-range IR to scan the line, due to terrain constraint. VGA would worth a try. Let me know if you have other ideas

fantasy1989: to spin a motor the other way, just reverse the polarity (+ve connect to -ve, and -ve connect to +ve). If you want better control, can try H-bridge circuit. H-bridge has the advantage of speed control and brake. To design H-bridge circuit, first need to know what motor you use, and what is the motor load (what the motor is use for). You can read up in wikipedia to understand the basic of H-bridge. Let us know what the motor is used for, we'll suggest a better way to that. Cheers

This sensor look kinda expensive, got water-prove somemore, want to install outdoor is it? Maybe you can try Jalan Pasar, try those shop that sell light, alarm. They may not have the specific model, but if you tell them what is your application, usually they can recommend you the alternative. But this only apply for manufactured parts

HB2E-DC5V, pin 3 and 14 are your input, give it a 5v supply and the relay will engage.
When engage, pin 8 and 2 will short, (aka connected), and pin 9 and 15 will short also.
When disengage, pin 8 and 1 will short, and pin 9 and 16 will short.
Usually this type of relay are used when you have 3 different circuit that run on different voltage supply. i.e., your switching supply run on 5v, and you need to use it to switch on a 12v circuit (pin 8 and 2, or 1) and another 24v circuit (pin 9 and 15, or 16).

What type of IR sensor? For what application?