Silicon Labs ARM Cortex-M3 processors

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Andy Peters

Well-known member
Joined
Oct 30, 2007
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2,031
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Sunny Tucson
I would like to point out that you can buy the SiM3C167, an 80 MHz ARM with two 1 MHz 10-bit ADCs, two DACs, onboard decently-accurate oscillator, tons of timers, UARTs, USARTs, I2C, SPI, up to 65 I/O, 256 kB flash, and 32 kB RAM, all in a DIY-friendly TQFP-80 for eight bucks, quantity one from Mouser, right now.

If you need less flash and less RAM, the SiMC136 is $4.25.

Eval kits are cheap. C compiler is free. Debug dongle is $35.

I can't see why I'd use an 8051 ever again.

-a
 
Andy,

as a counterpoint:http://www.ti.com/tool/ek-lm4f120xl

Stellaris Launchpad board is all ready to rock for $12.99

There should be a ton of software available for it too.

However, I'm still dabbling with the MSP430. (Launchpad is $4.30 inc shipping) Right now, I have trouble filling 1MHz (without crystal) with instructions!

/R
 
I cut my teeth on Microchip PICs so lean that way.

My current DIY project is to make a smart time of day temperature controlled controller for a small 850W heater I have laying around. I figure making this smart, can supplant my dumb in wall heater running 24x7 in my bedroom.

I have an old demo board for early 8 bit PIC family with a temperature sense IC on the demo board, but i can make a good enough temp sensor from a few diodes using the sundry A/D inputs. In fact I could use a few diodes in series, located around the room to get an average temp. Who cares about precision. This will be a lot more repeatable than my current crude mechanical thermostat on the in-wall heater.

Right now I am collecting parts.  I already bought the 16A TRIAC, when I was planning to make this (7A) heater adjustable with a low current lamp dimmer, but now I need to buy an opto-triac, to interface between my low voltage PIC micro controller platform and high current mains voltage TRAIC. I see some  $0.65 cent in one ea, 1a trigger opto-triacs, so this looks easy peasy.  PIC to opto 1A to 16A to heater.

Now I need to find time to crank out the DIY code..  just like Andy I don't want to go back to the old 8 bit micro so may modify one of my new 16 bit boards... At least one of my old 8 bit demo boards has an LCD display so that is tempting while the LCD is actually run from 4 bit interface... The easy path is to write this for the old 8 bit demo board platform. that buys me a real temp sensor and alpha-numeric readout.  Decisions decisions....

Simple time of day temp targets, and real time temp sensing. I plan to do a proportional controller running heating element for increments of full on/off cycles rather than phase control like regular lamp dimmers. The heating element has a long enough time constant that I don't need to fine regulate it.

I may sniff the low voltage AC to generate a clock time base, for TOD and roughly turn the triac on/off in full cycle increments.

OK the rough design is finished, where's my junior programmer to code it ??? nah, I'm the junior programmer too.... :-(

JR
 
Easy way to switch zero crossing all in one SSRs http://www.omega.com/pptst/G3NA.html is an example.

Someone I know that is going to build a nice Sous Vide told me about a web site that has nice under $40.00 PID temp controllers and inexpensive RTDs, I am looking for the website I forgot to save the bookmark.  Some temp controllers have adaptive PID and proportional control and other options.
Found it http://www.lightobject.com/

 
Gus said:
Easy way to switch zero crossing all in one SSRs http://www.omega.com/pptst/G3NA.html is an example.

Someone I know that is going to build a nice Sous Vide told me about a web site that has nice under $40.00 PID temp controllers and inexpensive RTDs, I am looking for the website I forgot to save the bookmark.  Some temp controllers have adaptive PID and proportional control and other options.
Found it http://www.lightobject.com/

I like that big dog SSR if I decide to expand smart control to my existing in wall radiant heating elements. But for now I am messing with a more modest 7A portable heater, so a couple dollars of triac, I already have in hand with a cheap opto-triac to trigger that will work for now and give me isolation from the mains. .

I actually worked on (repaired) a proportional controller back in the '70s so I understand the difference between light dimmers and heater coils. 

Who knows, if I like the result with my small heater, I might connect up to the bigger in-wall unit.

JR
 
http://www.lightobject.com/25A-Solid-State-Relay-SSR-DC-In-AC-Out-P61.aspx
look at the price.
 
Gus said:
http://www.lightobject.com/25A-Solid-State-Relay-SSR-DC-In-AC-Out-P61.aspx
look at the price.

Um  yes?  The guts are still << expensive than that. I like that package with screw terminals if I mess with my house wiring, but for now, I'm just plugging into outlets, so if anything it' s a little big and bulky.

I saved the link. JIC it makes sense later.

JR
 
The new ARM Cortex-M4F processors with some floating point DSP functionality are great and the evaluation kits inexpensive. For an example the Infineon XMC4500 Relax Lite kit which is only 10 EUR (+VAT+shipping):

http://www.infineon.com/cms/en/product/microcontrollers/32-bit-xmc4000-industrial-microcontrollers-arm-registered-cortex-tm-m4/xmc4000-development-tools,-software-and-kits/xmc4500-relax/relax-lite-kit/channel.html?channel=db3a30433a747525013a97f6e265721e

It's got three I2S interfaces (which Infineon oddly calls IIS, and uses strange names for the I2S signals as well) , FLASH and some SRAM (not much though). With 120 MHz CPU you could handle couple of biquads for speaker crossovers for an example.
 
Andy,

  Does the Cortex M3 have the full set of ARM 32 bit instructions? I know some ARM version dropped the old 32 bit barrel shifter from ALU ops. For example the instruction BIC r3,r2,r1 lsl r0

In a past life I wrote 100K+ of assembly language pixel twiddling code for ARMs but it used the full 32 bit instruction set with barrel shiffter.

I would love to find a low cost platform to run that code.

Bob K.
 
rkondner said:
Andy,

  Does the Cortex M3 have the full set of ARM 32 bit instructions? I know some ARM version dropped the old 32 bit barrel shifter from ALU ops. For example the instruction BIC r3,r2,r1 lsl r0

In a past life I wrote 100K+ of assembly language pixel twiddling code for ARMs but it used the full 32 bit instruction set with barrel shiffter.

I would love to find a low cost platform to run that code.

Bob K.

Honestly, there are too many variants and flavors, so I don't know whether the instruction set implemented in M3 devices is the "full set" or not.

According to this, the barrel shifter is included in the ALU data path.

BTW, I do everything in C.

-a
 
It is stunning the amount of performance that can be packed into simple micro controllers for just a few dollars.  For essentially $10, you can have the performance of 20-30 IBM PC XT systems in the size of a postage stamp, costing only a 100mW of power.
 
Matador said:
It is stunning the amount of performance that can be packed into simple micro controllers for just a few dollars.  For essentially $10, you can have the performance of 20-30 IBM PC XT systems in the size of a postage stamp, costing only a 100mW of power.

+100

JR
 
Matador said:
It is stunning the amount of performance that can be packed into simple micro controllers for just a few dollars.  For essentially $10, you can have the performance of 20-30 IBM PC XT systems in the size of a postage stamp, costing only a 100mW of power.

Oh how we laughed!

Regards,
the year 2070
 
I've always wanted a Kyma, but could never afford one. Now I'm wondering if a bunch of processors like these on a board running some kind of Lisp-based DSP engine could do a lot of what I'd like, and be easier to deal with than DSPs.

Except most of the cost of the Kyma is probably the software.
 

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