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Topic: ILI9341(new)SPI library for Due supporting DMA transfer(Uno, Mega,.. compatible) (Read 86387 times) previous topic - next topic

HermannSW

> How can you show analog input values from the Arduino to the TFT?
>
This is how the TFT text output shown in photo is generated:
Code: [Select]
...
#include <ILI9341_due_config.h>
#include <ILI9341_due.h>
...
ILI9341_due tft = ILI9341_due(TFT_CS, TFT_DC, TFT_RST); //ILI9340
...
  char buf[1000];
...
  tft.begin();
  tft.setRotation(iliRotation270);
...
  tft.setFont(Arial_bold_14);
  tft.setFont(roboto16);
  tft.setFont(roboto32);
  tft.setTextLetterSpacing(5);
  tft.setTextColor(ILI9341_WHITE, ILI9341_BLUE);
//  tft.printAligned(F("Hello World"), gTextAlignMiddleCenter);
  tft.println(F("ultrasonic distance \nsensor tests \nmicros(): pulse[us]"));
...
  sprintf(buf, "%ld: %ld \n%ld: %ld \n%ld: %ld \n%ld: sprintf", t0, duration0, t1, duration1, t2, duration2, t3);
  tft.println(buf);
...


Hermann.

HermannSW

> > Can you measure the voltage on that pin and also on VCC as the screen goes black?
> >
> I just found the reason that I ruled out before, because I powered the 900mAh lipo just two days before.
> Lipo is simply low on power ...
>
I have seen TFT go black again after some time, while the digital voltmeter did show 11.3V for Due Vin.
Just to be absolutely sure I loaded the LiPo, and now voltmeter shows 12.0V.

In this situation I saw what I saw with 11.3V before, display runs fine for some seconds, then begins to flicker and finally turns black. Now I did measure between GND and VCC pin of TFT, and it was only 2.09V. This explains display black.

I powered the robot off, waited a minutes and powered on again. This time I measured between VCC and GND of TFT the whole time. Started >3V and remained there some seconds, then slowly and finally quicker drops and drops to 2.09V. I had no idea what could be the reason for this, because voltmeter still shows 12.0V. Then luckily I had my hands over Due DCA0/1 area and noticed a lot of heat. Seems this Due has a big problem (after some time). I remembered that this Due was hot before I mounted it on robot. No problem, I have 4 Dues, will switch with one of the other 3 Dues ...

I have seen good and bad microcontrollers, lost 2 Dues and many more Nanos and even more Minis (most likely due to overvoltage, dangling cables). But I have never seen a micro controller starting fine and then after some time running hot and stop working.

Hermann.

MarekB

Any chance you're drawing too much current from Due somewhere? That could be causing overheating and maybe damaging the Due.

Total DC Output Current on all I/O lines   130 mA
DC Current for 3.3V Pin   800 mA
Each pin can provide (source) a current of 3 mA or 15 mA, depending on the pin, or receive (sink) a current of 6 mA or 9 mA, depending on the pin.

electrobob

Hey, this is a very good library.
Any interest in making this run on the Zero/M0 using the SAMD21 ?

MarekB

Thanks. You're not the first one asking about it but no :) At least I do not have any plans to make it work for Zero in any near future.

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