Restrict user of certain pin/peripheral?

Other Hardware Hardware Development
1

Hi,

I'm designing an Arduino compatible board with some extra devices (a Nixie tube to be exact). Within the circuit I have a H-bridge driving a transform. The H-bridge is controlled by OC1A/OC1B which produce complementary waveforms. I've written a library to configure Timer 1 for the need.

Now I'm worry if the board is given to a user, who did not use the library I provided but run some arbitrary code on it. There is a risk that both high-side and low-side MOSFET of the H-bridge are turned on simultaneously which causes a dead-short.

So I'm thinking if there is a way to restrict user of accessing these pins either as digital I/O or PWM. Maybe through pins_arduino.h or remake a core directory with reduced functions.

I know this may not be feasible, and is surely not fool-proof. But just want to explore if any possibility.

Thanks

Baoshi

2

You can do that but you will have to hack the header files and have your own IDE, not a good idea.
How about simply using an inverter or transistor to generate the complement of a pin for driving the h- bridge?

3

You could use your own pins_arduino.h file to mark the relevant digial pins as "NOT_A_PORT" in the digital_pin_to_port_PGM array. This would only protect against a particular class of users, and it would cause programs to fail "silently" in mysterious manner if they tried to use the pins, but it might be better than nothing.