Memory in ESP8266, with Arduino IDE, seems less than 81920?
Posted: Sun Jul 05, 2015 5:19 amHi,
My apologies in advance if this is a newbie question, but I could not find the answer on the forums or by searching.
I am using an ESP8266, compiling using the Arduino environment. My device is NodeMCU 1.0 (ESP-12E), and I can compile
and run samples fine.
However, I have noticed that I only seem to have about 38K of RAM available. If I allocate (say) a couple of larger arrays, the compiler complains that
...address 0x3fffec80 of TestESP8266Memory.cpp.elf section `.bss' is not within region `dram0_0_seg'
and then dies.
The variables appear at the bottom of the bss section: just above 3FFE8000h, where there is supposed to be 0x14000 (81920) bytes free, but any variables over about 38K seem to exceed the RAM area allocated.
Can someone explain why I only appear to be able to access about half of the RAM?
I am just compiling a test like this:
Anyway - can someone explain the limitation? Is this to be expected?
Regards Hugh
My apologies in advance if this is a newbie question, but I could not find the answer on the forums or by searching.
I am using an ESP8266, compiling using the Arduino environment. My device is NodeMCU 1.0 (ESP-12E), and I can compile
and run samples fine.
However, I have noticed that I only seem to have about 38K of RAM available. If I allocate (say) a couple of larger arrays, the compiler complains that
...address 0x3fffec80 of TestESP8266Memory.cpp.elf section `.bss' is not within region `dram0_0_seg'
and then dies.
The variables appear at the bottom of the bss section: just above 3FFE8000h, where there is supposed to be 0x14000 (81920) bytes free, but any variables over about 38K seem to exceed the RAM area allocated.
Can someone explain why I only appear to be able to access about half of the RAM?
I am just compiling a test like this:
Code: Select all
void setup() {
Serial.begin(115200);
}
uint8_t a1[16384];
uint8_t a2[16384];
uint8_t a3[16384];
void loop() {
int b;
Serial.print("Address of a1,a2 is ");
Serial.print((long)&a1[0]);
Serial.print(",");
Serial.print((long)&a2[0]);
Serial.println();
delay(500);
}Anyway - can someone explain the limitation? Is this to be expected?
Regards Hugh