# MicroBlaze PID Firmware on PYNQ-Z2: Compiling with PMODB BSP

**URL:** <https://discuss.pynq.io/t/microblaze-pid-firmware-on-pynq-z2-compiling-with-pmodb-bsp/8741>\
**Category:** Support\
**Created:** [September 15, 2025, 1:47am UTC](https://discuss.pynq.io/t/microblaze-pid-firmware-on-pynq-z2-compiling-with-pmodb-bsp/8741 "2025-09-15T01:47:42Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Michel](https://avatars.discourse-cdn.com/v4/letter/m/ea666f/32.png) [@Michel](https://discuss.pynq.io/u/Michel)\
**Post date:** [September 15, 2025, 1:47am UTC](https://discuss.pynq.io/t/microblaze-pid-firmware-on-pynq-z2-compiling-with-pmodb-bsp/8741/1 "2025-09-15T01:47:42Z")

</div>

Hello PYNQ community,

I am working on a MicroBlaze-based PID controller for a drone on the **PYNQ-Z2 board**. My setup involves:

- A custom MicroBlaze project (`pid_mb.c`) that reads an MPU sensor via I²C and controls motors using a PCA9685 via a PMOD.

- Python control code using `pynq.lib.MicroblazeLibrary` to communicate with the firmware.

- I intend to use **PMODB** in my Python code as the hardware interface.

**What I am trying to achieve:**

- Compile the `pid_mb.c` firmware using the MicroBlaze toolchain.

- Run the firmware on the PYNQ-Z2.

- Control the drone’s motors through PMODB using Python.

**The issue I am encountering:**

- The BSP on the board is only for **PMODA** (`bsp_iop_pmod/iop_pmoda_mb`). There is no `bsp_iop_pmod/iop_pmodb_mb`

- In my makefile, to build My project I want to use PMODB(`bsp_iop_pmod/iop_pmodb_mb`) :

```auto
pid_mb.elf: $(OBJS) ../src/lscript.ld $(USER_OBJS)
	@echo 'Building target: $@'
	@echo 'Invoking: MicroBlaze gcc linker'
	mb-gcc -Wl,-gc-sections \
	       -Wl,-T ../src/lscript.ld \
	       -L../../bsp_iop_pmod/iop_pmodb_mb/lib \
	       -mlittle-endian -mcpu=v11.0 -mxl-soft-mul \
	       -Wl,--no-relax \
	       -o "pid_mb.elf" $(OBJS) $(USER_OBJS) $(LIBS)
	@echo 'Finished building target: $@'
	@echo ' '

```

- But Im getting this error because it does not exist:

```auto
xilinx@pynq:~/pynq/lib/pmod$ make
cd pid_mb/Debug && make clean && make

make[1]: Entering directory '/usr/local/share/pynq-venv/lib/python3.10/site-packages/pynq/lib/pmod/pid_mb/Debug'
rm -rf ./src/pid_mb.o ./src/pid_mb.d pid_mb.elf.size pid_mb.elf pid_mb.bin
make[1]: Leaving directory '/usr/local/share/pynq-venv/lib/python3.10/site-packages/pynq/lib/pmod/pid_mb/Debug'

make[1]: Entering directory '/usr/local/share/pynq-venv/lib/python3.10/site-packages/pynq/lib/pmod/pid_mb/Debug'

Building file: ../src/pid_mb.c
Invoking: MicroBlaze gcc compiler
mb-gcc -Wall -O0 -g3 -c -fmessage-length=0 \
       -MT "src/pid_mb.o" \
       -I ../../bsp_iop_pmod/iop_pmoda_mb/include \
       -mlittle-endian -mcpu=v11.0 -mxl-soft-mul -Wl,--no-relax \
       -MMD -MP -MF "src/pid_mb.d" -MT "src/pid_mb.d" \
       -o "src/pid_mb.o" "../src/pid_mb.c"

Finished building: ../src/pid_mb.c

Building target: pid_mb.elf
Invoking: MicroBlaze gcc linker
mb-gcc -Wl,-gc-sections \
       -Wl,-T ../src/lscript.ld \
       -L ../../bsp_iop_pmod/iop_pmodb_mb/lib \
       -mlittle-endian -mcpu=v11.0 -mxl-soft-mul \
       -Wl,--no-relax \
       -o "pid_mb.elf" ./src/pid_mb.o \
       -Wl,--start-group,-lxil,-lgcc,-lc,--end-group

/opt/microblazeel-xilinx-elf/bin/../lib/gcc/microblazeel-xilinx-elf/9.2.0/../../../../microblazeel-xilinx-elf/bin/ld: cannot find -lxil
collect2: error: ld returned 1 exit status
make[1]: *** [makefile:40: pid_mb.elf] Error 1
make[1]: Leaving directory '/usr/local/share/pynq-venv/lib/python3.10/site-packages/pynq/lib/pmod/pid_mb/Debug'

make: *** [makefile:38: pid_mb.bin] Error 2

```

## So my question would be Is there a way to create or obtain a **PMODB BSP** for PYNQ-Z2 so I can compile the firmware to work with PMODB?