Show Posts
Pages: 1 [2] 3 4 ... 6
16  Products / Arduino Due / Re: Arduino Due for SPI with raspberry pi on: September 14, 2013, 03:25:34 pm
master will set the clock, slave doesn't care

you set the PI to 16Mhz , it has a clock OUTPUT
i have not looked on how to set the clock on the PI

you do not set a clock for the slave(DUE) - it has a clock INPUT

17  Products / Arduino Due / Re: Arduino Due for SPI with raspberry pi on: September 14, 2013, 11:34:26 am
from the data sheet AT91SAM3x  shows 2 'pure' SPI  (Table 33-2,33-3)  & 4 'USART' SPI  (Table 36-1+36-3)

the USART & pure SPI are not setup the same way - esp for DMA /PDC
& as far as the wiring you would have to trace the info in the tables above to see if they are all brought out to aa location that is useable

many lines have mutiple functions

from the data sheet it does look like you could program spi clk  to be MCLK/1 but i doubt many perhierals could tolerate that ...
which is slave which is master between the PI & DUE ?
master will set the clock slave doen't care (as long as it is fast enough ...)
18  Products / Arduino Due / Re: Arduino Due for SPI with raspberry pi on: September 13, 2013, 02:42:16 pm
1) I belive you can get up to 42Mhz on the spi

2) both the due & the pi are 3.3vdc  so no level shifter requierd

3)  i don't understand your question -
 are you asking about the the spi periperal ? the xmit & recv are shared between periperials (of which you can have upto 15**)
  or are you asking about other spi  - the usarts can be used as spi ...

**don't recall if all the CS lines are available
19  Community / Gigs and Collaborations / Re: Ways to implement Arduino + OV2460 time lapse photography on: August 27, 2013, 03:27:11 pm
"I only know DMA will work with communications between host CPU and DRAM chips, but certainly not with SD cards which has ."

the cortexM3 (DUE/stm32/others) core has perphieral DMA (PDC) , so essentually can DMA directly to the SPI ... if programed correctly

where did you get the AL422B ?? direct from mfg ?? 
20  Products / Arduino Due / Re: Due'ish with more ram ? on: August 22, 2013, 08:52:11 pm
i should have done a bit more research prior to ask the questions ...
 I have a fpga board in front of me that has a 32Mx16 chip / i presumed it was sram ... D'oH  it is DRAM

 looking up vendors, looks like best choice may be a Pseudo SRAM  but its a pain to find a vendor that sells a tsop package in a size >8Mbit

21  Products / Arduino Due / Re: Due'ish with more ram ? on: August 22, 2013, 04:34:12 pm
can't be a sheild just because the way the DUE was wired (few signals messed up / mis wired )
needs a brand new board --

- i'd take a swing at it but i'm behind on projects as it is ...
22  Products / Arduino Due / Due'ish with more ram ? on: August 22, 2013, 11:35:07 am
I like the DUE , have two of them but they are crippled from a external memory point of view ..

Has anyone looked into locating or building a board that has the memory maxed out ? ( 16Megx8 using one chipselect )
23  Products / Arduino Due / Re: Just for confirmation: DUE cannot have external parallel RAM? on: August 01, 2013, 07:29:19 am
Yes. I have seen that thread. "    
Parallel library for Due External Memory Bus/Static Memory Controller "

What is NRD?
NRD == RD active low
NWR == WR active low
24  Products / Arduino Due / Re: standalone native USB port? on: July 18, 2013, 07:00:11 pm
as seen from another thread my programming port is non-functional 
i have been programming via the Native port by
1) pressing erase
2) pressing reset
3) uploading sketch ..

PITA but it works ...
25  Products / Arduino Due / Re: Parallel library for Due External Memory Bus/Static Memory Controller on: July 18, 2013, 10:53:54 am
interesting project & will experiment with it in the next few days

I have in mind a large fifo  32Meg'ish (fpga tied to a sdram)
using no addresses - just reads & writes (need the PWM lines for other aspects of my programs) 
accounting can be taken care of by the Due
It would need a NWE/NRD/NBSx line

This is all to be rid of SDcard latency - i have too much data throughput  to deal with 100-300ms delay 
26  Products / Arduino Due / Re: werid error - No device found on: July 16, 2013, 07:04:15 am
 reply to my own post :
pretty sure the ATMEGA16U2 has lost its programming ..  
what hardware is needed to reflash it ?

never mind

-- was able to dig up the info / for the record

A) avrdude.exe / avrdude.config is not located where the doc say -- it is in:

B) the hexfile is buried pretty deep

C) I used a Nano as a AVRISP which has the same pinouts as the UNO descibed in

D) the Nano would error out ("avrdude: stk500_getsync(): not in sync: resp=0x15") without the required a 120ohm resistor  between Vcc & reset

--- this was all to no avail - my Due still can not be programed via the USB Programming port
to program my Due requires a tenitive connection to the USB native port which resets after every upload (^#&$%&%!!!)
27  Products / Arduino Due / werid error - No device found on: July 11, 2013, 09:42:27 am
been working on my second Due for 8 weeks or so 
suddenly i started getting No device found on COM5

i tried the Native port  & can program the device -
but the programming port seems to be kaput ..
Due #1 / the nano / & others work fine ...
tried to change to COM10  no effect ..

anybody seen this before?
28  Products / Arduino Due / Re: Due generating Synchronous PWM on: June 10, 2013, 12:57:50 pm
it not really using syncronous channels as the data sheet states / you are just using both outputs of the same channel .. `
(i didnt need dead time .. but easy to add.. )

in anyevent  here is a chunk of code that sets up TWO seperate channels (two differnt duty cycles )
if you want to just use channel outputs 5H & 5L  rip out the "syncronous" stuff (channel 0 & channel 4)
(ALSO .. i didnt need dead time .. but easy to add.. )

PWM_setup ()
//PWM config
  pmc_enable_periph_clk (ID_PWM);

  PWMC_DisableChannel (PWM, PWM_CHANNEL_4);
  PWMC_DisableChannel (PWM, PWM_CHANNEL_5);
  PWMC_DisableChannel (PWM, PWM_CHANNEL_0);

  PWMC_ConfigureClocks (pwm_clk, 0, VARIANT_MCK);

  int ulPin = 8;
  // Setup PWM for this pin {theta1}
  PIO_Configure (g_APinDescription[ulPin].pPort,
  ulPin = 9;
  // Setup PWM for this pin  {thetaRB}
  PIO_Configure (g_APinDescription[ulPin].pPort,
  //**pin44        {theta2}
  PIO_Configure (g_APinC19RE_Description.pPort,

  PWMC_ConfigureSyncChannel (PWM,
     , PWM_SCM_UPDM_MODE1, 0, 0);

  PWMC_SetPeriod (PWM, PWM_CHANNEL_4, pwm_period);
  PWMC_SetPeriod (PWM, PWM_CHANNEL_5, pwm_period);

  PWMC_ConfigureChannel (PWM, PWM_CHANNEL_4, PWM_CMR_CPRE_CLKA, 0,
  PWMC_SetDutyCycle (PWM, PWM_CHANNEL_4, pwm_dutyRS);
  PWMC_SetDutyCycle (PWM, PWM_CHANNEL_5, pwm_duty1);

  PWMC_SetPeriod (PWM, PWM_CHANNEL_0, pwm_period);
  PWMC_SetDutyCycle (PWM, PWM_CHANNEL_0, pwm_duty1);
  PWMC_ConfigureChannel (PWM, PWM_CHANNEL_0, PWM_CMR_CPRE_CLKA, 0, 0);

  PWMC_SetSyncChannelUpdatePeriod (PWM, 1);

  PWMC_ConfigureComparisonUnit (PWM, PWM_CHANNEL_5, 1, 1);
  PWMC_ConfigureComparisonUnit (PWM, PWM_CHANNEL_4, 1, 1);
  PWMC_ConfigureEventLineMode (PWM, 0, PWM_ELMR_CSEL5 | PWM_ELMR_CSEL4);
  PWMC_SetSyncChannelUpdateUnlock (PWM);

  PWMC_EnableChannel (PWM, PWM_CHANNEL_0);
  PWMC_SetSyncChannelUpdateUnlock (PWM);
29  Using Arduino / Storage / Re: Compact Flash Interface? on: June 03, 2013, 02:36:54 am
like this ?
30  Using Arduino / Storage / Re: extra RAM on Arduino Due on: May 31, 2013, 02:34:56 am
I built an external sram device with XC9536XL ($1) and a 4MBytes large SRAM chip. You need 11 wires to control the memory (8data+3bit control). With bigger cpld (more pins) you can access an "unlimited" size of sram. It has got an auto increment feature thus a rd/wr to the device automatically increments the sram's address.

i looked at a similar method but it requires to much processor intervention
- using SPI/USART with PDC/DMA should get up to 4MBytes/sec with very little processor intervention ...

my chunks are 4096bytes occuring once every 5ms (and faster if i can make other improvements)
so low processor over head is very important to me ..
Pages: 1 [2] 3 4 ... 6