LeafLabs Garden » Topic: How many free memories are there when Maply starts?

LeafLabs Garden » Topic: How many free memories are there when Maply starts? http://forums.leaflabs.com/topic.php?id=13341 A place to share, learn, and grow... en-US Fri, 22 Jan 2016 00:20:21 +0000 http://bbpress.org/?v=1.0.2 <![CDATA[Search]]> q http://forums.leaflabs.com/search.php gbulmer on "How many free memories are there when Maply starts?" http://forums.leaflabs.com/topic.php?id=13341#post-28380 Fri, 09 Aug 2013 07:19:22 +0000 gbulmer 28380@http://forums.leaflabs.com/ joyzhou - That's a very interesting result. Thank you for sharing. It's a bit disappointing, I did expect more. Did you try starting at too big a value? The idea is to see if the initial malloc's are fragmenting memory. <pre><code>// The code(in setup): int i; void * p; for(i=20*1024; i>1024;i--){ SerialUSB.print(i); p = malloc(i); if(p==NULL){ SerialUSB.println("\t failed"); continue; } else{ SerialUSB.println("\tOK"); free(p); delay(100); } }</code></pre> joyzhou on "How many free memories are there when Maply starts?" http://forums.leaflabs.com/topic.php?id=13341#post-28373 Thu, 08 Aug 2013 19:13:46 +0000 joyzhou 28373@http://forums.leaflabs.com/ gbulmer - Thank you for the suggestions. I simplified the sketch. <pre><code>// The code(in setup): int i; void * p; for(i=1024;i<20*1024;i++){ SerialUSB.print(i); p = malloc(i); if(p==NULL){ SerialUSB.println("\t failed"); break; } else{ SerialUSB.println("\tOK"); free(p); } }</code></pre> The result: ... ... 13562 OK 13563 OK 13564 OK 13565 OK 13566 failed That is, when a simplest program starts, there are at least 13566 bytes of *continuous* RAM. The total free RAM may be larger. I will modify the code to solve the problem. (Edit: I added code quotes to make it easier to read. I hope that is okay. gbulmer) gbulmer on "How many free memories are there when Maply starts?" http://forums.leaflabs.com/topic.php?id=13341#post-28370 Thu, 08 Aug 2013 07:12:17 +0000 gbulmer 28370@http://forums.leaflabs.com/ joyzhou - I'd suggest you make setup() simpler, and more likely to work, so that you can isolate the bug. For example: <pre><code>#define BUF_SIZE 10 void setup(void) { pinMode(BOARD_LED_PIN, OUTPUT); SerialUSB.begin(); pinMode(BOARD_BUTTON_PIN, INPUT); while(!isButtonPressed()){ toggleLED(); delay(200); } unsigned int asize = BUF_SIZE * sizeof(kiss_fft_scalar); SerialUSB.print("size of allocation ="); SerialUSB.println(asize); kiss_fft_scalar * rin =(kiss_fft_scalar*) malloc(asize); if(rin == NULL ){ SerialUSB.println("mycfg failed."); return; } }</code></pre> There are conflicting documents for malloc(), one says it doesn't work: <a href="http://leaflabs.com/docs/language-index.html?highlight=malloc" rel="nofollow">http://leaflabs.com/docs/language-index.html?highlight=malloc</a> and the other says it does: <a href="http://leaflabs.com/docs/faq.html?highlight=malloc" rel="nofollow">http://leaflabs.com/docs/faq.html?highlight=malloc</a> I never use it, so I'm not sure which applies (I thought it did work, but I can't remember why). Edit: I haven't checked but I would guess at least 16KB would be free. It may not be working because the 'premain' initialisation might be incorrect, but I don't know that is the case. You might try a dumb program, only with setup() and loop(), using the Maple IDE to see if it makes a difference. (Full disclosure: I am not a member of LeafLabs staff.) joyzhou on "How many free memories are there when Maply starts?" http://forums.leaflabs.com/topic.php?id=13341#post-28367 Thu, 08 Aug 2013 03:34:08 +0000 joyzhou 28367@http://forums.leaflabs.com/ Hello everyone. I am trying to do some FFT on maple_mini with the kiss_fft. The program always failes to malloc(1024*sizeof(float)), while the maple mini has 20KB of RAM. Why? Here is the code: <pre><code>#include <math.h> #include <stdlib.h> #include <wirish/wirish.h> #include "kiss_fftr.h" #define BUF_SIZE 1024 void setup(void) { pinMode(BOARD_LED_PIN, OUTPUT); SerialUSB.begin(); pinMode(BOARD_BUTTON_PIN, INPUT); while(!isButtonPressed()){ toggleLED(); delay(200); } kiss_fftr_cfg mycfg = kiss_fftr_alloc(BUF_SIZE, 0, NULL, NULL); kiss_fft_scalar * rin =(kiss_fft_scalar*) malloc(BUF_SIZE * sizeof(kiss_fft_scalar)); kiss_fft_cpx * fout = (kiss_fft_cpx*) malloc((BUF_SIZE/2+1) * sizeof(kiss_fft_cpx)); if(mycfg == NULL ){ SerialUSB.println("mycfg failed."); return; } if(rin == NULL){ SerialUSB.println("rin failed."); return; } if(fout == NULL){ SerialUSB.println("fout failed."); return; } SerialUSB.println("allocations OK."); for(int i=0;i<BUF_SIZE;i++){ rin[i] = sin((float)i/20.0f) + 0.5*cos((float)i/30.0f); } unsigned long t0, t1; t0 = micros(); kiss_fftr(mycfg, rin, fout); t1 = micros(); SerialUSB.println(t1 - t0); kiss_fftr_free(mycfg); free(rin); free(fout); } void loop(void) { digitalWrite(BOARD_LED_PIN, HIGH); delay(50); digitalWrite(BOARD_LED_PIN, LOW); delay(800); } __attribute__((constructor)) void premain() { init(); } int main(void) { setup(); while (true) { loop(); } return 0; }</code></pre>