Cheap ARM development boards with 64K RAM or more?

[splin]

STM32F103C8T6 boards can be had for $2.15 each on Aliexpress but only have 64K FLASH and 20K RAM. Moving up to the Maple mini clones gets you 128K FLASH for $4 each including shipping but still only 20K RAM.

It's hard to beat boards that cost less than the individual components - the STM32F103CBT6 alone on the Maple mini cost $6.43 a piece from Digikey, so probably $10+ with shipping, taxes etc. in small quantities!

So any suggestions for any cheap, and preferably reasonably small, ARM boards with, say, 128K FLASH and plenty of RAM - 64K or more would be good?

Any Cortex core would be OK but an M3 or M4 would be good. I don't need USB or fancy peripherals although some decent timers and 8 or more 12bit ADC channels would be good. Doesn't need to be an ST device; their Nucleo boards are OK but a bit big and probably at least $16 all in - which is still excellent value but is there anything cheaper?

I see the LPC54101J256UK49Z is very aggressively priced at 1K quantity at less than $2.8 for 100MHz M4, 256K FLASH 104K RAM. Are there any low cost boards which use it?

[jeremy]

the TI 1294XL are pretty neat. 1MB flash and 256k SRAM for ~$20 USD from digikey. Also has the onboard debugger, etc as you would expect.

[zapta]

The teensys are popular with good library support.

https://www.pjrc.com/teensy/teensy31.html#specs

[f1rmb]

Hi,

   The STM32F103VET6 have 512k of flash and 64k of SRAM:

http://www.ebay.com/itm/NEW-STM32F103VET6-ARM-STM32-Minimum-System-Development-Board-Cortex-m3-GM-/262136737783?hash=item3d08912ff7:g:S7YAAOSwYHxWIMcm


Cheers.
---
Daniel

[michaeliv]

Are you looking for cheap boards or cheap micros ? What quantity ?
For your scenario chips can be bought much cheaper than boards.
Here is cheapest meating your specs :
$12 for 64kb/512kb - http://www.aliexpress.com/item/1pcs-STM32F103VET6-ARM-STM32-Minimum-System-Development-Board-Cortex-m3/32346393972.html

Chips are way cheaper
$2.50 for 64kb/64kb - http://www.aliexpress.com/af/STM32F105R8T6.html?ltype=wholesale&d=y&origin=n&isViewCP=y&site=glo&shipCountry=US&SortType=price_asc&SearchText=STM32F105R8T6&isFreeShip=y&isUnitPrice=y&maxQuantity=200&page=1
$2.80 for 384kb/64kb - http://www.aliexpress.com/af/STM32F103RDT6.html?ltype=wholesale&d=y&origin=n&isViewCP=y&site=glo&shipCountry=US&SortType=price_asc&SearchText=STM32F103RDT6&isFreeShip=y&isUnitPrice=y&maxQuantity=200&page=1

[sca]

STM32F429 discovery?

sca

[westfw]

Someone has to say it:  Raspberry Pi?  C.H.I.P ?

[daybyter]

http://m.aliexpress.com/item/32603308880.html

[michaeliv]

A somewhat unrelated question -- How do they manage to make the chips on the Raspberry pi Zero / Orange Pi / CHIP so cheaply. The Chip + RAM + board + passives are cheaper than a lower spec micro.
Is it only volume ? Anyone have any idea how much the micro on the Raspberry pi Zero costs and how much the RAM costs ?

[Rasz]

A somewhat unrelated question -- How do they manage to make the chips on the Raspberry pi Zero / Orange Pi / CHIP so cheaply. The Chip + RAM + board + passives are cheaper than a lower spec micro.
Is it only volume ? Anyone have any idea how much the micro on the Raspberry pi Zero costs and how much the RAM costs ?

they dont, 20KB ram micros sold at $2 are a TOTAL effin RIPOFF, pee zero is sold ~at a cost.
This is why chinese are making stm32 clones and selling them at 1/5 the price still making good profit.

[Kilrah]

The Pi Zero is most likely sold at a loss that is billed to the marketing account. Was an awesome tool to get the entire world to talk about it, but now it's perpetually out of stock because obviously the more you sell the more you lose, so gotta trickle the output to the minimum that still lets people believe they have a chance to get one.

[splin]

Thanks for all the suggestions but apart from the Pi zero they are all, including the (teensy @ $20) more expensive than the much more powerful Nucleo STM32F446RET6 (180MHz M4, 512K/128K) at just less than $11 + tax, so $13 here in the UK from RS. There's no shipping or customs charges as I can collect them locally.

The Pi and Orange Pi are both cheap but I am after a Cortex Mx solution. The power consumption is likely to be too high as well. The ST discovery boards are good but they are a touch more expensive than the Nucleos and have various unwanted peripheral devices, using more power and using up some of the I/O ports.

Are you looking for cheap boards or cheap micros ? What quantity ?
For your scenario chips can be bought much cheaper than boards.
Here is cheapest meating your specs :
$12 for 64kb/512kb - http://www.aliexpress.com/item/1pcs-STM32F103VET6-ARM-STM32-Minimum-System-Development-Board-Cortex-m3/32346393972.html

Chips are way cheaper
$2.50 for 64kb/64kb - http://www.aliexpress.com/af/STM32F105R8T6.html?ltype=wholesale&d=y&origin=n&isViewCP=y&site=glo&shipCountry=US&SortType=price_asc&SearchText=STM32F105R8T6&isFreeShip=y&isUnitPrice=y&maxQuantity=200&page=1
$2.80 for 384kb/64kb - http://www.aliexpress.com/af/STM32F103RDT6.html?ltype=wholesale&d=y&origin=n&isViewCP=y&site=glo&shipCountry=US&SortType=price_asc&SearchText=STM32F103RDT6&isFreeShip=y&isUnitPrice=y&maxQuantity=200&page=1

Amazing isn't it. Assuming they are genuine ST chips, $2.38 @ 50 off including shipping for the 384k/64k part compared to Digikey who want nearly tree times as much - $6.74 @ 100 off!

For now I want boards but will eventually move to a custom PCB. Because I don't need much in the way of integrated peripherals apart from an ADC and timers it's not essential to find a development board that has the same micro as the eventual target board as the firmware changes shouldn't be too significant.

Main problem with the Nucleos, is that it is presumably subsidized and targeted at developers to get them hooked on ST parts. I don't know what their attitude would be to them being used in quantity (< 100), for use in prototypes/first run production items. I was wondering if there were any Chinese bargains, like the $2 STM32F103 boards, but with more RAM. It doesn't look like it unfortunately as there size is also just about perfect too.

A somewhat unrelated question -- How do they manage to make the chips on the Raspberry pi Zero / Orange Pi / CHIP so cheaply. The Chip + RAM + board + passives are cheaper than a lower spec micro.
Is it only volume ? Anyone have any idea how much the micro on the Raspberry pi Zero costs and how much the RAM costs ?

they dont, 20KB ram micros sold at $2 are a TOTAL effin RIPOFF, pee zero is sold ~at a cost.
This is why chinese are making stm32 clones and selling them at 1/5 the price still making good profit.

Ah - your reply came in as I was typing the above. OK, so perhaps they are clones, but does that apply to most ST micros from China or just the almost ubiquitous (in all sorts of Chinese products) STM8S103F3P6 and the lower end STM32F103 parts?

[Rasz]

they dont, 20KB ram micros sold at $2 are a TOTAL effin RIPOFF, pee zero is sold ~at a cost.
This is why chinese are making stm32 clones and selling them at 1/5 the price still making good profit.

Ah - your reply came in as I was typing the above. OK, so perhaps they are clones, but does that apply to most ST micros from China or just the almost ubiquitous (in all sorts of Chinese products) STM8S103F3P6 and the lower end STM32F103 parts?

http://www.gigadevice.com/product-category/11.html

you misunderstood me, chinese clone lowest stm32 part

EDIT: forgot to finish my thought
chinese clone lowest stm32 model, but that doesnt mean all cheap parts are clones, ST is forced to sell cheaply or be replaced by domestic micros - this is why you can get individual original stm32 parts from china at 1/2 farnell full reel discount price.

$2-15 for a piece of silicon with a size that is a FRACTION of 2GBits memory chip, when you can buy DIMM module with 8 of those 2GBit chips at $9 RETAIL should tell you something.
http://www.amazon.com/Crucial-PC3-12800-Unbuffered-240-Pin-CT25664BA160B/dp/B006YG88QC
just let that sink in, ~16 billion transistors / $9 = ~1.7 billion transistors for a dollar, retail
Cortex-M3 has afair ~100K transistors, another 700K for fattest sram/rom option and we end up at ~1mil transistors. 1000 less than what you get in a ram chip at similar price point.

Whole ram/flash price differentiation is a huge scam, the most expensive part of any ARM microcontroller is packaging
Most lower end stm32 parts are same silicon across whole family, just fused differently. Sometimes they dont even bother and you end up with stm32f103c8t6 (theoretical 64KB flash) having 128KB.

[Kilrah]

more expensive than the much more powerful Nucleo STM32F446RET6 (180MHz M4, 512K/128K) at just less than $11 + tax, so $13 here in the UK from RS.

Main problem with the Nucleos, is that it is presumably subsidized and targeted at developers to get them hooked on ST parts.

Obviously, the whole point of dev boards costing about nothing (sometimes less than the chip itself) nowadays is to lower the entry point as much as possible, and make it very easy for you to get into, hoping that once you've figured it out and manage to build a proto you'll shell out for the part (that may be a bit more expensive than a competitor to compensate) instead of having to potentially spend more time (and thus lose more than that excess) porting your now working PoC to a different part.

Can't argue it being better than what was done a couple of decades ago where the mood of the day was "unless you buy our $5k development kit we don't care about you". Thanks to that we can get pretty high spec parts for cheap.

[Back2Volts]

EVAL KIT TM4C123GXL LAUNCHPAD  32Bits, 80Mhz, 256KB / 32KB / 2KB, around $13.
http://www.digikey.com/product-search/en?keywords=ek+tm4c123gxl&WT.srch=1&gclid=COrV-K7z18sCFQgxaQodnQEIeg

[michaeliv]

EVAL KIT TM4C123GXL LAUNCHPAD  32Bits, 80Mhz, 256KB / 32KB / 2KB, around $13.
http://www.digikey.com/product-search/en?keywords=ek+tm4c123gxl&WT.srch=1&gclid=COrV-K7z18sCFQgxaQodnQEIeg

What the ... is that a complete board with 2xTM4C123G for about the same price of a single TM4C123G ?

[jeremy]

Yes, it's pretty incredible.

[Back2Volts]

EVAL KIT TM4C123GXL LAUNCHPAD  32Bits, 80Mhz, 256KB / 32KB / 2KB, around $13.
http://www.digikey.com/product-search/en?keywords=ek+tm4c123gxl&WT.srch=1&gclid=COrV-K7z18sCFQgxaQodnQEIeg

What the ... is that a complete board with 2xTM4C123G for about the same price of a single TM4C123G ?

Yes.  I have one and it surprised me when I realized there where two of the same MCU.  One of them is used as the degug interface.

[cezar]

Have a look on STM32F446RE  and on ST's Nucleo dev boards

http://uk.farnell.com/stmicroelectronics/nucleo-f446re/dev-brd-stm32f446re-arduino-mbed/dp/2491978

[TonyD]

http://www.gigadevice.com/product-category/11.html

you misunderstood me, chinese clone lowest stm32 part

Olimex mentioned then a few weeks back

[stmdude]

A somewhat unrelated question -- How do they manage to make the chips on the Raspberry pi Zero / Orange Pi / CHIP so cheaply. The Chip + RAM + board + passives are cheaper than a lower spec micro.
Is it only volume ? Anyone have any idea how much the micro on the Raspberry pi Zero costs and how much the RAM costs ?

It's lock-in, more or less. They can charge a premium for the MCUs because they know companies have invested too much time/money/know-how in their code-base to switch.
Switching you app from running on a Broadcom SoC (Raspberry) to running on a AllWinner SoC (Banana Pi/Cubieboard/etc) most likely wouldn't even require a recompile..  Hence, the customers can switch freely, and that drives down the prices.

Funny thing.. I've got a board with an AllWinner A20 SoC, and an STM32F429 on it. The A20 is a dual-core Cortex-A9 @ 1GHz, with SATA, HDMI, 3x USB, Ethernet interaces..  The STM chip still costs _four times_ as much..  (Including the price for the PMIC for the A20, but not the DDR RAM).

 

[MT]

author=Rasz
just let that sink in, ~16 billion transistors / $9 = ~1.7 billion transistors for a dollar, retail
Cortex-M3 has afair ~100K transistors, another 700K for fattest sram/rom option and we end up at ~1mil transistors. 1000 less than what you get in a ram chip at similar price point.

Had no idea we paid for number of transistors, i thought we paid for the amount of plastic!

Whole ram/flash price differentiation is a huge scam, the most expensive part of any ARM microcontroller is packaging

How can that be? LQFP48 are cheaper then QFP32 (STM32) according to Farnell!

Most lower end stm32 parts are same silicon across whole family, just fused differently. Sometimes they dont even bother and you end up with stm32f103c8t6 (theoretical 64KB flash) having 128KB.

Does this apply to other devices such as F3 F4 as well or is it only valid for F103C8?
Has anyone conducted a out of range Flash write/read test to see?