cheap C-Stamp comming this fall

tonyp12

Adding another product in my pipe-line.
USB rom driver, program-flash shows up as file folder on your PC. (Sorry no step-debugging)

Add headers for breadboard or solder directly to the work area.
after it been reused ~5 times and starting to get crummy, get another one as target price is $5.95 (not a loss leader)

LPC11U24 (or better if NXP coming out with something new at $1.70 price point @1K)
50MHz, 32K Flash, 8K Ram, 8channel 10bit A/D.
Free mbed Studio online IDE, or IAR workbench.

Still making some layout changes, so if you have some suggestions.

Publison

Tony,
I don't see any relationship to Parallax products with this announcement, unless I am missing something.

erco

I thought you meant A-AWIT's C-Stamp from a few years ago.

https://en.wikipedia.org/wiki/C_Stamp

User Name

At first glance it reminded me of the CY8CKIT-049-42xx, perhaps because a stack of the latter is sitting on my workbench right now. At $3.99/ea, it's a cutthroat business you are competing in, Tony.

I like the ARM Cortex M0 family, but it seems like I'm always in a hurry to make everything. In the time it would take me to get set-up and productive coding a new ARM board, I already have its Propeller equivalent finished and installed. That is why the stack of Cypress boards isn't shrinking very fast.

jmg

tonyp12 wrote: »

LPC11U24 (or better if NXP coming out with something new at $1.70 price point @1K)
50MHz, 32K Flash, 8K Ram, 8channel 10bit A/D.

I would suggest a Nuvoton M452 series part, as better suited to 'Stamp-like' use.
This is still in TQFP48, so should need minimal PCB changes, but has true 5.5V operation, and a faster M4 core, all for less $

Cortex-M4 with DSP and FPU, 72MHz, Operating voltage: 2.5V to 5.5V

https://direct.nuvoton.com/en/m452le6ae

M452LE6AE 128kF 32k Ram, 8ch 12b ADC, 1 12b DAC $1.89/1k
M452LD3AE 72kF, 16k Ram 10 ch 12b ADC, 1 12b DAC $1.60/1k
M452LC3AE 40kF, 16k Ram 10 ch 12b ADC, 1 12b DAC $1.52/1k
(there is a 256k version showing in TQFP48, not yet in their web store)


You can get one of their $20 eval boards to run it up & compare, and look at CooCox, who have tools.
http://www.coocox.org/code/home.php?componentId=206&componentName=M451

tonyp12

NXP is always the lowest price on Mouser, on anything from 74hc595 to ARM's.
I'm not sure if the others have ROM based USB drivers where it shows up as a file folder, for you to just tell compiler to save the code to.
mbed ide seems pretty user-friendly: https://developer.mbed.org/handbook/mbed-Compiler

My BOM will be around $3.50, so I will not make much but something so I feel the time I spend porting my tiny co-operative event machine and also my tiny pre-emptive multitasker (see below).
As most people get stuck when it comes to doing many things at the same time, so I will get them started on the right track.

  int* multistack = (int*) __get_SP_register();
  int i=0; while(i<tasks-1){
    int j = stacksize[i]; 
    multistack -= j;  
    *(multistack) = (int) taskpnt[++i];         // prefill in PC 
    *(multistack-1) = GIE;                      // prefill in SR
    taskstackpnt[i] = (int) multistack-26;      // needs 12 dummy push words
  }
  WDTCTL = WDTPW+WDTTMSEL+WDTCNTCL;             // 4ms interval at 8MHz smclk
  IE1 |= WDTIE;
  __bis_SR_register(GIE);
  asm ("br &taskpnt");                          // indirect jmp to first task
}

//============= TASK SWITCHER ISR =============
#pragma vector = WDT_VECTOR 
__raw __interrupt void taskswitcher(void)
{
  asm ("push R15\n push R14\n push R13\n push R12\n"
       "push R11\n push R10\n push R9\n push R8\n"
       "push R7\n push R6\n push R5\n push R4");

  taskstackpnt[taskrun] = __get_SP_register();
  if (++taskrun == tasks) taskrun = 0;
  __set_SP_register(taskstackpnt[taskrun]);
  
  asm ("pop R4\n pop R5\n pop R6\n pop R7\n"
       "pop R8\n pop R9\n pop R10\n pop R11\n"
       "pop R12\n pop R13\n pop R14\n pop R15");
}