diff --git a/troubleshooting.md b/troubleshooting.md new file mode 100644 index 0000000..1232d55 --- /dev/null +++ b/troubleshooting.md @@ -0,0 +1,62 @@ +I sucked at handling my Rpi gpio pins. +I got everything backward you could. +I blew up a MAX-31855 chip. POOF, UP IN SMOKE! +Don't be like me... + +If you're using a breadboard with a labeled break-out board, verify +where pin one is using a multimeter. it sounds stupid, but it will save you time. +measure the voltage between all the 3V3 pins and a GND pin +measure the voltage betwwen all the GND pins and a GND pin +measure the voltage between the 5V pins and a GND pin. +if everything measures as expected, continue. if not, go back to the first step. + +run +gpio readall +and make sure the mode for all GPIO pins you want to test have a Mode of IN +if not, set the mode for each.. + +# set BCM pin 4 as an input +gpio -g mode 4 input + +# verify it got set correctly using +gpio readall + +# enable pull-down resistor for pin 4 to make sure V stays +# zero when nothing is connected to the input +gpio -g mode 4 down + + + +-----+-----+---------+------+---+---Pi 3---+---+------+---------+-----+-----+ + | BCM | wPi | Name | Mode | V | Physical | V | Mode | Name | wPi | BCM | + +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+ + | | | 3.3v | | | 1 || 2 | | | 5v | | | + | 2 | 8 | SDA.1 | IN | 1 | 3 || 4 | | | 5v | | | + | 3 | 9 | SCL.1 | IN | 1 | 5 || 6 | | | 0v | | | + | 4 | 7 | GPIO. 7 | IN | 0 | 7 || 8 | 0 | IN | TxD | 15 | 14 | + | | | 0v | | | 9 || 10 | 1 | IN | RxD | 16 | 15 | + | 17 | 0 | GPIO. 0 | IN | 0 | 11 || 12 | 1 | IN | GPIO. 1 | 1 | 18 | + | 27 | 2 | GPIO. 2 | IN | 0 | 13 || 14 | | | 0v | | | + | 22 | 3 | GPIO. 3 | IN | 0 | 15 || 16 | 0 | IN | GPIO. 4 | 4 | 23 | + | | | 3.3v | | | 17 || 18 | 0 | IN | GPIO. 5 | 5 | 24 | + | 10 | 12 | MOSI | IN | 0 | 19 || 20 | | | 0v | | | + | 9 | 13 | MISO | IN | 0 | 21 || 22 | 0 | IN | GPIO. 6 | 6 | 25 | + | 11 | 14 | SCLK | IN | 0 | 23 || 24 | 1 | IN | CE0 | 10 | 8 | + | | | 0v | | | 25 || 26 | 1 | IN | CE1 | 11 | 7 | + | 0 | 30 | SDA.0 | IN | 0 | 27 || 28 | 1 | IN | SCL.0 | 31 | 1 | + | 5 | 21 | GPIO.21 | IN | 0 | 29 || 30 | | | 0v | | | + | 6 | 22 | GPIO.22 | IN | 0 | 31 || 32 | 0 | IN | GPIO.26 | 26 | 12 | + | 13 | 23 | GPIO.23 | IN | 0 | 33 || 34 | | | 0v | | | + | 19 | 24 | GPIO.24 | IN | 0 | 35 || 36 | 0 | IN | GPIO.27 | 27 | 16 | + | 26 | 25 | GPIO.25 | IN | 0 | 37 || 38 | 0 | IN | GPIO.28 | 28 | 20 | + | | | 0v | | | 39 || 40 | 0 | IN | GPIO.29 | 29 | 21 | + +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+ + | BCM | wPi | Name | Mode | V | Physical | V | Mode | Name | wPi | BCM | + +-----+-----+---------+------+---+---Pi 3---+---+------+---------+-----+-----+ + +watch gpio readall + +connect a 3V3 pin in series to a 1k ohm resistor +connect the other end of the resistor to each gpio pin +when it is connected V should be 1 +when it is disconnected V should be 0 +my breadboard uses the BCM gpio pin numbering