My MKR1000 gets stuck sometimes when I try to print to a thermal printer connected to its 3.7V battery, I'm thinking it is because Brown Out Reset (battery voltage falls from 4V to 2.5V sometimes).
I have been investigating about fuses in arduino.
I know that every time you program using arduino IDE, it returns fuses (thus BOR or BOD configurations) to a standard configuration, as I know, you can see that "standard" in the file "boards.txt" usually located at
C:\Program Files (x86)\Arduino\hardware\arduino\avr
but it only contains models other than MKR1000
So, do MKR1000 have fuses?
Can I disable BOR by software?
What is the Standard Brown Out Voltage Limit of MKR1000?
You didn't give the capacity of the battery (important bit of info)
Or the specs of the printer (current consumption, nominal operating voltage etc)
Best guess after a quick look around is almost 1 amp required for most of the cheaper printers
Thermal printers as small as some are also consume a good amount of current.
You are probably correct to assume it is chewing up the juice and making the MKR drop out.
Actual current usage on the MKR will depend on a few factors such as how many and what type of other sensors etc are connected to it.
If you consider that the USB connector can supply 500mA from a proper USB port and use that as a very rough base number.
Take that and the 1A needed for the printer and you are around 1.5A not including anything else.
That needs to be a good battery that can supply that for long period without dropping in terms of both voltage and current.
Consider putting the printer on its own supply...
I know there are some very low voltage ones out there but most need more than 5 volts and probably nearer 9 volts to operate properly.
Hi! thanks for your reply. Your are right in your assumptions:
Battery is a Lipo 5,000mAh @3.7V, it is connected directly to the arduino, and it is also connected to a step up converter from 3.7V to 5V (maximum 2A output), from which the printer is connected to.
I have measured peak currents of about 1.5A in the printer. Printer is from Adafruit Thermal Printer.
I didn't described my elements as I really need to understand BOR and fuses in MKR1000, I'm looking for a software solution as I don't have the chance to modify hardware or give an external power source, but firmware yes. So my question is still open.
So, do MKR1000 have fuses?
Can I disable BOR by software?
What is the Default Brown Out Voltage Limit of MKR1000?