Buerstenmacher / wiringnano

c++ implementation of sysfs interface to control gpio pins on nvidia jetson nano

Jetson Nano

J41 Header Pinout

Name	Physical	Physical	Nmae
3.3VDC	1	2	5.0VDC
i2c_2_sda	3	4	5.0VDC
i2c_2_scl	5	6	GND
gpio 216	7	8	uart_2_TX
GND	9	10	uart_2_RX
gpio 50	11	12	gpio 79
gpio 14	13	14	GND
gpio 194	15	16	gpio 232
3.3VDC	17	18	gpio 15
gpio 16	19	20	GND
gpio 17	21	22	gpio 13
gpio 18	23	24	gpio 19
GND	25	26	gpio 20
i2c_1_sda	27	28	i2c_1_scl
gpio 149	29	30	GND
gpio 200	31	32	gpio 168
gpio 38	33	34	GND
gpio 76	35	36	gpio 51
gpio 12	37	38	gpio 77
GND	39	40	gpio 78

You can use this code to control the gpio-pins on your NVIDIA-Jetson-Nano. 😄

But remeber that gpio pins on the Jetson-Nano can only supply about 0,5mA of current. That's not enough to light up a standard led. 😞

To swicht an gpio_input from 0 to 1 and back to 0 you will need aproximately 5mA. I'm usiug an low voltage OpAmp (LM324) to control gpio inputs via gpio outputs. ✔️

This is a c++11 header-only repository. Do not search for .cpp files! 😉

You will need a c++11 compiler. 💻 if you use g++: the appropriate compile-flag is "-std=c++11"

Usage:

---

create an object of wiringnano class:

wiringnano pin79{79};
//pin79 is now an object representing gpio79 == pin12 on J41 header

---

set a gpio to high voltage --> 3.3V:

pin79.pullhi();

or call:

pin79.write(1);

---

set a gpio to low voltage --> 0.0V :

pin79.pulllo();

or call:

pin79.write(0);

---

set a gpio to high input impendance without reading it's voltage:

pin79.flow();

---

read a gpio value and output it to user:

std::cout << uint16_t(pin79.read()) <<std::endl;   
//for std::cout you will have to convert uint8_t to some other integer to prevent it from beeing interpretet as char 
//this should output 0 if you connect a 1k resistor from GND    to pin 12
//this should output 1 if you connect a 1k resistor from 3.3VDC to pin 12
//do NOT wire it directly if you dont have a resistor!!!

---

Do not forget to run your code as superuser!