Microcontroller mayhem

296

Jul 7, 2006 at 11:05 AM

Hey all, I've gotten a bit antsy about having something new to play with and have decided to once again try to pick up a microcontroller. I figured I deserved something little for my birthday. [wink] I don't know about many microcontrollers, but I really like this kit -- it's a multicore microcontroller with a Python-like high level language, VGA, TV, PS/2 and a decent amount of memory. There are 3D games running on it already, apparently, and it seems like a great deal. The only problem is that the software for it is Windows-only. I have a Windows box, and I'll be running Parallels Desktop on my MBP, but I'm not a terribly large fan of Windows for new software development. So I'm not really pleased with the tools at the moment, but this is what I'll probably end up buying (if only for the awesome video support and the cool demos that have been written thus far). I've also been looking at the Atmel AVR Butterfly because it's unbelievably cheap, and the tools are mature and very nice (avr-gcc is my friend). As well, I've been looking at some of Parallax's BASIC stamps and the oopic. Zilog seems to have a new embedded CPU, the Z108, but no evaluation board with it that I can poke around with. [crying] I also can't find any evaluation boards from Freescale, nor any ARM7/ARM9 hobbyist boards at a decent price. The SX52 is a bit underpowered for my taste (again with very poor tools), but if the price is right I'd like to pick one of those up too. The Javelin stamp is also really cool, but the starter kit seems a bit expensive and is back-ordered. I'm also pretty shit at surface-mount soldering, so excessive amounts of soldering (e.g. CPU pins) will probably be duffed up by me. The occasional cable mount solder is probably fine. I'm more or less getting this to hack software. Also, does anyone know if Atmel will let me request an AVR Butterfly for a free sample from their "free samples" page? Might as well save me some cash. [wink] Hell, I'd probably take anything usable from them for free. Are there any microcontroller kits that I've missed? I'd at least like some tools, a cable and some documentation. Bonus points if I can build apps on Linux or Mac OS X. My price range is pretty much sub-$300, though I'd really prefer sub-$200.

526

Jul 7, 2006 at 11:10 AM

If you decide to go for the BASIC Stamp - look at PICAXE microcontrollers instead, and save yourself some money.

Author

296

Jul 7, 2006 at 11:13 AM

Quote:
Original post by benryves
If you decide to go for the BASIC Stamp - look at PICAXE microcontrollers instead, and save yourself some money.

Wow, that's really cheap. I'm still quite tempted by the Propeller for the video-out capability; it reminds me of a NUON on chip. I wonder if I could chain PICs to make some sort of super-PIC. [wink]

Also, come to think of it... I think I still have that TI-89 Titanium I bought and then never used. I wonder if I can hook it up to a nicer display somehow. I was looking for a 68K or PPC board from Freescale, but they don't appear to sell them at hobbyist prices (> $500)

Maybe even a GP2X is a better idea than this, though I do really like the easy concurrency on the Propeller (and the GP2X is like $60 more). Graar. So many toys.

526

Jul 7, 2006 at 11:27 AM

Aye, built-in video is cool, but building your own video signals in software is even cooler [wink] (Though, for timing reasons, that's pushing you more to assembly coding). If you're more into the software side, going for a kit that does a lot of the hardware for you (eg Propeller) seems a better bet rather than going for the very simplistic low-end microcontrollers; not something I can really comment on.

As long as you can get the microcontrollers in a DIL package (DIP), couldn't you get a bunch of breadboards rather than rely on soldering?

Whichever way you go, I'll be interested to see what you can get out of it...

Author

296

Jul 7, 2006 at 11:30 AM

I think I will end up buying the Propeller just because I'd rather hack software -- the multitude of ports looks like it'll also be simple for me to hook up retarded hardware and make it work.

I do appreciate the mention of cheap PICs; what's the assembly language like for those little bastards? All I can see on their site is documentation for Basic.

526

Jul 7, 2006 at 11:41 AM

Quote:
Original post by Ravuya
I do appreciate the mention of cheap PICs; what's the assembly language like for those little bastards? All I can see on their site is documentation for Basic.

PICAXE chips (and the like) are actually regular PICs with a bit of extra firmware preinstalled on them (that's what you pay for, in effect) - for example, that firmware provides the RS232 interface used by the programming cable to copy your program to the chip, rather than having to shell out for the programmer hardware you'd need to buy if you were writing to blank PICs. As such, assembly programming is not possible on a PICAXE (as far as I'm aware) unless you send your own program onto the chip using a standard PIC programmer.

As for the assembly language on these PICs... describing them as 'little bastards' is close enough for me (tiny stack, few registers - very confined environment).

Author

296

Jul 7, 2006 at 11:47 AM

So many things to buy. Would you happen to know what kinds of free shit Atmel will send a hobbyist, or do I have to pretend to be a giant engineering corporation to get a blister pack of AVRs?

137

Jul 7, 2006 at 12:30 PM

Well the only way to find out is to try, however looking at their order samples page I reckon they won't send samples to hobbyists no harm in trying though [grin] Other companies freely send out samples though, Microchip and Maxim IC (They have a huge range of various useful ICs) are two to check out for that.

Personally I'm gonna be buying a Spartan-3E Development Board soon and attempting to get something game-like out of it though that's got an FPGA so you've gotta build your own processor pretty much (it does come with a full implementation you can use).

Spark Fun have some nice stuff though it can be a tad expensive.

110

Jul 7, 2006 at 12:52 PM

Try Analog's Blackfin boards if you're also into DSP. Blackfin's are a great cross between traditional microcontrollers and DSPs. These guys have AVR/Blackfin boards, which you can find cheap on eBay. Analog also sells their own boards, in single-core and dual-core variations, along with a bunch of expansion boards. And, there's a STAMP variation which runs uCLinux if you're interested, which is being sold at a good discount here.

CrimsonSun

Jul 7, 2006 at 12:53 PM

I'm currently using the OOPic for a project of mine, and I must say I am very pleased with it. It has plenty of I/O lines and has SCP capability. It's also expandable as you can hook up more OOPics in network fashion.

This probably isn't in your budget, but I saw it when I was browsing around for a microcontroller, but it looks very interesting.

DrjonesDW3d

Jul 7, 2006 at 1:01 PM

If you want a linux environment, check out the Blackfin family.

They were designed as DSP chips, so have some interesting applications.

The nice thing is that there is a version of uclinux that runs on them. Thus, you can write linux code that will control what the chip does.

The stamp board for the BF537 is just under $200 I believe, and will basically runn uclinux out of the box. I believe there are modules and things you can purchase to get video output.

Depending on what you are doing, the blackfin chips might be overkill. However, there are a decent number of microcontrollers suppored under uclinux, so you might check them out.

Author

296

Jul 7, 2006 at 1:23 PM

I... don't know if I'm into DSP. [wink]

I probably don't need complex DSPs to write simple games, do I? I'd look into something like the XGameStation were it not based on the hated SX52 chip. I think the next generation XGameStation is to be based on the Propeller.

The Blackfin hardware looks totally awesome (especially uClinux -- being able to get experience with uClinux on something other than a uCdimm would be a feather in my cap), but the starter kit is very expensive.

Extrarius

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Extrarius

Jul 7, 2006 at 2:06 PM

Quote:
Original post by Ravuya
[...]it's a multicore microcontroller with a Python-like high level language

What is the purpose of programming a microcontroller in a high-level language? If you want to do that, you might as well just target a PDA or handheld console. IMO, the point in playing with microcontrollers is to either play with hardware or low-level software.
If you don't mind shelling out for a PIC programmer, you can get them for free from MicroChip in limited quantities.
A little more info is available in my previous thread "PIC Microcontroller Programming ". I don't know whether tools exist for OSes besides Windows, though.

Author

296

Jul 7, 2006 at 2:25 PM

Quote:
Original post by Extrarius
Quote:
Original post by Ravuya
[...]it's a multicore microcontroller with a Python-like high level language
What is the purpose of programming a microcontroller in a high-level language? If you want to do that, you might as well just target a PDA or handheld console. IMO, the point in playing with microcontrollers is to either play with hardware or low-level software.

It has assembly language too, but it looks like the Propeller is effectively a NUON with video hardware. The board is pretty tricked-out; I'll probably be using it to play with games in a tight, multicore environment. Besides, I want to play with cool little boards and I don't care much about the classification, particularly if the aforementioned cool little board has a shitload of processing power. I can also launch your precious assembly on a thread from within it.

Also, isn't a BASIC Stamp a microcontroller? You program those little guys in BASIC (or Java or C-like HLL with the oopic and javelin).

Quote:
If you don't mind shelling out for a PIC programmer, you can get them for free from MicroChip in limited quantities.
A little more info is available in my previous thread "PIC Microcontroller Programming ". I don't know whether tools exist for OSes besides Windows, though

I'll look, but I probably need a board and power supply or something to get those little PICs to do something interesting.

[Edited by - Ravuya on July 7, 2006 10:25:31 PM]

133

Jul 7, 2006 at 3:14 PM

I second Monder's suggestion for using an FPGA. The Spartan 3 is quite nice and a couple semesters ago I built a very simple 8-bit frame buffered video game system using a Spartan 3 (on the eval. board) and a Z80 microprocessor.

See here under "Circuits."

The nice thing about using sub-20MHz processors is that you don't have to worry about RF issues and PCBs. You can breadboard your designs and easily interface them to an FPGA evaluation board. The boards will often provide a VGA port. One company makes an evaluation board with a 1 million gate Spartan 3 and a VGA port with a 512-color DAC for $200.

Author

296

Jul 7, 2006 at 10:33 PM

Digi-Key seems to have a Xilinx Spartan3 starter kit (122-1471-ND) for $99 USD but I see no mention of this kit on Xilinx's website outside of a PDF manual for the model number (they have a similar kit for the same amount of money as the Propeller kit, as DigiKey seems to be out of the 122-1471-ND). I'd still like to futz around with the Propeller kit, but the Xilinx kit is an FPGA, something I've wanted to buy for awhile.

110

Jul 8, 2006 at 12:20 AM

Don't get a Spartan 3 if you want a decent display. It has a VGA output with just 3-bit colour, so unless you're prepared to build yourself a decent DAC you wont get much out of it on that front. Good board otherwise, however. Note that the Spartan 3 and Spartan 3E are different boards, the 3E might offer a better DAC. You might also try some of Altera's FPGAs and CPLDs, they might offer cheap boards with better video output.

137

Jul 8, 2006 at 3:54 AM

Quote:
It has a VGA output with just 3-bit colour, so unless you're prepared to build yourself a decent DAC you wont get much out of it on that front.

Yeah I know, the plan is to build a DAC, the board has a 4 channel one on however I don't think it'll be fast enough (I was hoping to drive a standard PC monitor at 640x480 with 8-bit colour on each channel). I would appreciate some advice on how to go about sorting this out actually, as I've been researching it a bit and I'm not entirely sure what to do.

roel

Jul 8, 2006 at 4:32 AM

I used 3 different microcontrollers in my life: motorola's 68hc11, an ancient philips which name I cant remember and various Atmels, and I had the best experience with those from Atmel.

But it really depends on what you want to do with your microcontroller, say, there is quite a big difference between automating your lights in your home or processing digital video data.

133