docs: additional info about how to install and use this package

Signed-off-by: deadprogram <[email protected]>

Author: deadprogram

README.md

@@ -1,4 +1,7 @@
 # pio
+
+[![Build](https://github.com/tinygo-org/pio/actions/workflows/build.yml/badge.svg)](https://github.com/tinygo-org/pio/actions/workflows/build.yml)
+
 Provides clean API to interact with RP2040's on-board Programable Input/Output (PIO) block.
 See chapter 3 of the [RP2040 datasheet](https://datasheets.raspberrypi.com/rp2040/rp2040-datasheet.pdf#page=310) for more information.
 
@@ -32,3 +35,35 @@ again:
     set pins, 0     ; Drive pin low
     jmp again       ; Set PC to label `again`
 ```
+
+### How to install pioasm
+
+To develop new code using PIO with this package, you must build and install the `pioasm` tool. It can be be built from the pico-sdk:
+
+```shell
+git clone [email protected]:raspberrypi/pico-sdk.git
+cd pico-sdk/tools/pioasm
+cmake .
+make
+sudo make install
+```
+
+### How to develop a PIO program
+
+To develop a PIO program you first start out with the .pio file. Let's look at the Pulsar example first.
+
+1. `pulsar.pio` specifies a binary PIO program that can be loaded to the PIO program memory.
+2. `all_generate.go`: holds the code generation command on the line with `//go:generate pioasm -o go pulsar.pio     pulsar_pio.go` which by itself generates the raw binary code that can be loaded onto the PIO along with helper code to load it correctly inside `pulsar_pio.go`.
+3. `pulsar_pio.go`: contains the generated code by the `pioasm` tool.
+4. `pulsar.go`: contains the User facing code that allows using the PIO as intended by the author.
+
+### Regenerating piolib
+
+```shell
+cd rp2-pio/piolib
+go generate .
+```
+
+### Other notes
+
+Keep in mind PIO programs are very finnicky, especially differentiating between SetOutPins and SetSetPins. The difference is subtle but it can be the difference between spending days debugging a silly conceptual mistake. Have fun!