Updating comverting instructions

books/beaglebone-cookbook/11misc/figures/Makefile

+obj-m += tmp114.o
+
+KDIR ?= /lib/modules/$(shell uname -r)/build
+PWD := $(CURDIR)
+
+all:
+        make -C $(KDIR) M=$(PWD) modules
+
+clean:
+        make -C $(KDIR) M=$(PWD) cleanobj-m += tmp114.o
+
+KDIR ?= /lib/modules/$(shell uname -r)/build
+PWD := $(CURDIR)
+
+all:
+        make -C $(KDIR) M=$(PWD) modules
+
+clean:
+        make -C $(KDIR) M=$(PWD) clean

books/beaglebone-cookbook/11misc/misc.rst

 .. _beaglebone-cookbook-misc:
 
+.. |I2C| replace:: I\ :sup:`2`\ C
+
 Misc
 ####
 
@@ -58,7 +60,7 @@ We've seen tmp006 and tmp007 before, tmp117 is new. Maybe it will work.  Click o
 Looks like it also works for the tmp116.  Let's try convering it to work with the tmp114.
 
 A quick way to copy the code to the bone is to right-click on the **plain** link and select *Copy link address*.
-Then, on the bone enter **wget** and past the link.  Mine looks like the following, yours will be similar.
+Then, on the bone enter **wget** and paste the link.  Mine looks like the following, yours will be similar.
 
 .. code-block:: bash
 
@@ -66,4 +68,217 @@ Then, on the bone enter **wget** and past the link.  Mine looks like the followi
   bone$ mv 'tmp117.c?h=v6.4-rc7' tmp117.c
   bone$ cp tmp117.c tmp114.c
 
+The **mv** command moves the downloaded file to a usable name and the **cp** copies to a new file with the new name.
+
+Compiling the module
+^^^^^^^^^^^^^^^^^^^^
+
+Next we need to compile the driver.  To do this we need to load the corresponding header files for the
+version of the kernel that's beening run.
+
+.. code-block:: bash
+
+  bone$ uname -r
+  5.10.168-ti-arm64-r105
+
+Here you see which version I'm running, yours will be similar.  Now load the headers.
+
+.. code-block:: bash
+
+  bone$ sudo apt install linux-headers-`uname -r`
+
+Next create a *Makefile*.  Put the following in a file called *Makefile*.
+
+.. _misc_makefile:
+
+.. literalinclude:: figures/Makefile
+   :caption: Makefile for compiling module (Makefile)
+   :linenos:
+
+:download:`Makefile <figures/Makefile>`
+
+Now you are ready to compile:
+
+.. code-block:: bash
+
+    bone$ make
+    make -C /lib/modules/5.10.168-ti-arm64-r105/build M=/home/debian/play modules
+    make[1]: Entering directory '/usr/src/linux-headers-5.10.168-ti-arm64-r105'
+    CC [M]  /home/debian/play/tmp114.o
+    /home/debian/play/tmp114.c: In function ‘tmp117_identify’:
+    /home/debian/play/tmp114.c:150:7: error: implicit declaration of function ‘i2c_client_get_device_id’; did you mean ‘i2c_get_device_id’? [-Werror=implicit-function-declaration]
+    150 |  id = i2c_client_get_device_id(client);
+        |       ^~~~~~~~~~~~~~~~~~~~~~~~
+        |       i2c_get_device_id
+    /home/debian/play/tmp114.c:150:5: warning: assignment to ‘const struct i2c_device_id *’ from ‘int’ makes pointer from integer without a cast [-Wint-conversion]
+    150 |  id = i2c_client_get_device_id(client);
+        |     ^
+    cc1: some warnings being treated as errors
+    make[2]: *** [scripts/Makefile.build:286: /home/debian/play/tmp114.o] Error 1
+    make[1]: *** [Makefile:1822: /home/debian/play] Error 2
+    make[1]: Leaving directory '/usr/src/linux-headers-5.10.168-ti-arm64-r105'
+    make: *** [Makefile:7: all] Error 2
+
+Well, the good news is, it is compiling, that means it found the correct headers.  
+But now the work begins converting to the tmp114.
+
+Converting to the tmp114
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+You are mostly on your own for this part, but here are some suggestions:
+
+- First get it to compile without errors.  In this case, the function at line 150 isn't defined.
+  Try commenting it out and recompiling.
+- Once it's compiling without errors, try running it. First open another window and login to beagle.
+  Then run:
+
+  .. code-block:: bash
+
+    bone$ dmesg -Hw
+
+This will display the kernel messages.  The **-H** put them in *human* readable form, and the **-w** waits for 
+more messages.
+
+- Next, "insert" it in the running kernel:
+
+.. code-block:: bash
+
+    bone$ sudo insmod tmp114.ko 
+
+If all worked you shouldn't see any messages, either after the command or in the dmesg window.
+If you want to insert the module again, you will have to remove it first.
+Remove with:
+.. code-block:: bash
+
+    bone$ sudo rmmod tmp114
+
+Now we need to tell the kernel we have an |I2C| device and which bus and which address.
+
+Finding your |I2C| device
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Each |I2C| device appears at a certain address on a given bus.  My device is on bus 3,
+so I run:
+
+.. code-block:: bash
+
+     i2cdetect -y -r 3
+        0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
+    00:                         -- -- -- -- -- -- -- --
+    10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+    20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+    30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+    40: -- -- -- -- -- -- -- -- -- -- -- -- -- 4d -- --
+    50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+    60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+    70: -- -- -- -- -- -- -- --
+
+This shows there is a device at address **0x4d**. If you don't know your bus number, 
+just try a few until you find it.
+
+The temperature is in register 0 for my device and it's 16 bits (one word),
+it is read with:
+
+.. code-block:: bash
+
+    bone$  i2cget -y 3 0x4d 0 w
+    0xb510
+
+The tmp114 swaps the two bytes, so the real temperature is **0x10b5**, or so.
+You need to look up the datawsheet to learn how to comvert it.
+
+Registers and IDs
+^^^^^^^^^^^^^^^^^
+
+Each |I2C| device has a number of internal registers that interact with the device.
+The tmp114 uses different register numbers than the tmp117, so you need to change these values.
+To do this, Google for the data sheets for each and look them up. 
+I found them at: https://www.ti.com/lit/gpn/tmp114 and https://www.ti.com/lit/gpn/TMP117.
+
+Creating a new device
+^^^^^^^^^^^^^^^^^^^^^
+
+Once you've converted the module for the tmp114 and inserted it, you can now create a new device.
+
+.. code-block:: bash
+
+    bone$ cd /sys/class/i2c-adapter/i2c-3
+    bone$ sudo chgrp gpio *
+    bone$ sudo chmod g+w *
+    bone$ ls -ls
+    total 0
+    0 --w--w---- 1 root gpio 4096 Jun 22 18:24 delete_device
+    0 lrwxrwxrwx 1 root root    0 Jan  1  1970 device -> ../../20030000.i2c
+    0 drwxrwxr-x 3 root gpio    0 Jun 22 18:20 i2c-dev
+    0 -r--rw-r-- 1 root gpio 4096 Jun 22 18:20 name
+    0 --w--w---- 1 root gpio 4096 Jun 22 18:20 new_device
+    0 lrwxrwxrwx 1 root root    0 Jan  1  1970 of_node -> ../../../../../firmware/devicetree/base/bus@f0000/i2c@20030000
+    0 drwxrwxr-x 2 root gpio    0 Jun 22 18:20 power
+    0 lrwxrwxrwx 1 root root    0 Jan  1  1970 subsystem -> ../../../../../bus/i2c
+    0 -rw-rw-r-- 1 root gpio 4096 Jun 22 18:20 uevent
+
+The first line changes to the directory to where we can create the new device.
+The final **3** in the path is for bus **3**, your milage may vary.
+We then change the group to **gpio** and give it write permission.
+You only need to do this once.
+
+Now make the device.
+
+.. code-block:: bash
+
+    bone$ echo tmp114 0x4d > new_device
+
+Look in the demsg window and you should see:
+
+.. code-block:: bash
+
+    [Jun22 19:24] tmp114 3-004d: tmp114_identify id (0x1114)
+    [  +0.000027] tmp114 3-004d: tmp114_probe id (0x1114)
+    [  +0.000502] i2c i2c-3: new_device: Instantiated device tmp114 at 0x4d
+
+It's been found! Let's see what it knows about it.
+
+.. code-block:: bash
+
+    bone$ iio_info
+    Library version: 0.24 (git tag: v0.24)
+    ...
+            iio:device1: tmp114
+                    1 channels found:
+                            temp:  (input)
+                            2 channel-specific attributes found:
+                                    attr  0: raw value: 4257
+                                    attr  1: scale value: 7.812500
+                    No trigger on this device
+
+I've left out some of the lines, at the bottom you see the tmp114, and
+two values (**raw** and **scale**) that were read from it.  Let's read them ourselves.
+Do an *ls* and you'll see a new directory, **3-004d**.  This is address 0x4d on bus 3,
+just what we wanted.
+
+.. code-block:: bash
+
+    bone$ cd 3-004d/iio:device1
+    bone$ ls
+    dev  in_temp_raw  in_temp_scale  name  power  subsystem  uevent
+    bone$ cat in_temp_raw
+    4275
+
+You'll have to look in the datasheet to learn how to convert the temperature.
+
+If you try to run i2cget again, you'll get an error:
+
+.. code-block:: bash
+
+    bone$ i2cget -y 3 0x4d 0 w
+    Error: Could not set address to 0x4d: Device or resource busy
+
+This is because the module is using it.  Delete the driver and you'll have access again.
+
+.. code-block:: bash
+
+    bone$ echo 0x4d > /sys/class/i2c-adapter/i2c-3/delete_device
+    bone$ i2cget -y 3 0x4d 0 w
+    0x8e10
 
+You should also see a message in dmesg.