====== Getting the Wiring Right ======

===== Raspberry Pi 3+ =====


In 2018 the Preinstalled BlueJ IDE, the Pi4J library that was in the directory ''/usr/share/bluej/userlib/''  did not recognize my new pi 3 B+. After [[http://wiringpi.com/wiringpi-updated-for-the-pi-v3plus/|installing the latest WiringPi]] and [[http://pi4j.com/install.html|intalling the latest Pi4J]], 
I still had to
<code>
sudo rm /usr/share/bluej/userlib/*.jar
sudo cp /opt/pi4j/lib/*.jar /usr/share/bluej/userlib/
</code>
because the new ''jar'' files of the Pi4j were stored in ''/opt/pi4j/lib/'' and ignored by BlueJ because of the old version in ''/usr/share/bluej/userlib/''. 

Descriptions of the [[http://pi4j.com/pins/model-3b-plus-rev1.html|new pin out numbers]] and [[http://pi4j.com/usage.html|usage]] are at [[http://Pi4j.com]].

 {{http://pi4j.com/images/j8header-3b.png}}

From the terminal:\\
<code>
pi@rbpi:~ $ gpio readall
 +-----+-----+---------+------+---+---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 | 1 |  7 || 8  | 0 | IN   | TxD     | 15  | 14  |
 |     |     |      0v |      |   |  9 || 10 | 1 | IN   | RxD     | 16  | 15  |
 |  17 |   0 | GPIO. 0 |   IN | 0 | 11 || 12 | 0 | 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 | 1 | 27 || 28 | 1 | IN   | SCL.0   | 31  | 1   |
 |   5 |  21 | GPIO.21 |   IN | 1 | 29 || 30 |   |      | 0v      |     |     |
 |   6 |  22 | GPIO.22 |   IN | 1 | 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 |  OUT | 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+--+---+------+---------+-----+-----+

</code>
The kit I bought from CanaKit had wriiten the BCM numbers, but I needed to program with the wPi numbers.
===== Raspberry Pi 400 =====
In 2022 I got a Raspberry Pi4 400. Unfortunately, it was so new, the old gpio -v gave me the message "Oops - unable to determine board type... model: 19"

I found some help at [[https://pi4j.com/1.4/install.html]].  I followed the "Easy Method" which produced the {{ ::pi4j-core.jar}} file that I needed.  In order for BlueJ to find it, I copied it over to the proper directory:

<code>sudo cp /opt/pi4j/lib/*.jar /usr/share/bluej/userlib/</code>

[[https://pi4j.com/1.3/pins/rpi-400.html| GPIO pins on the 400]]