I set up an Arduino with an rf433 module and an microSD to store the transmitted values. Everything worked out but now. I wanted to add an RTC and a 5110 display. If I comment out the display or the RTC it is working, but both together end up in restarting or freezing the Arduino... I tested USB from PC and external power supply via USB (but as far as I know USB is always limited to 500mA) and also a 12V with 1.5A on the power jack.
I was thinking it's an power issue even if I doubt this 4 devices can cause an issue, but now I did the measuring. Without back light of the display I got:
Display 1mA,
RF433 3mA
RTC 2mA
microSD 9mA
So I assume it's not really an power issue? (<200mA for all pins, <40mA on a single pin)
I also tried an USB doctor which doesn't show anything because of the low consumption.
Is there e.g. an issue with software SPI (display) and I2C (RTC) when using at the same time?
I don't really know where I can look for the failure, it almost looks like some kind of compatibility issue... I even tried another display and RTC. Didn't have time by now to test a different software / setup by now and ain't got time till next month, so I thought I might ask here and maybe someone has an idea.
The odd thing is, when I comment out the display, the RTC is working, if I comment out the RTC the display is working, but this might not be the real issue but that's why I can tell the code seems to be fine. I'm not using the same pins for this devices.
See if the problem still occurs with the full code but without anything connected to your Arduino board. That will tell you whether the problem is in the code.
Don't forget if you are powering with 12V through the barrel jack the 5V regulator is already dropping 7V, so more than 200 - 300 mA drawn off the 5V pin will cause it to overheat and shut down.
Display 1mA, How much with backlight on?
RF433 3mA " " when transmitting?
RTC 2mA
microSD 9mA " " when transferring data?
Thank you very much guys, I was finally able to dig deeper.
Can't tell you what exactly the issue is, maybe it's a compatibility issue with the combination of Uno, SD and 5110 display, for whatever reason. I found another topic, that recommends to use different MOSI and SCK for the SD/display and now it is working.
@pert - very useful advise, hope I remember when I'm in trouble again.
@jremington - I appreciate your comment and I do understand the need for the code. I was quite in a hurry and didn't have the time to clean up my code, that's why I just wanted a brainstorm.
@outsider - the RF current was from the transmitting state, SD might have been idle since the issues occurred very early in the program flow.
@MarkT - wasn't aware of that, I'll have an eye on that so I don't run into further issues, thank you.
