ULP blink

Me trying to make an esp32 blink via ULP.

Since there is no PlatformIO integration for ULP, I'll use plain ESP-IDF. But I reuse the PlatformIO framework for espidf. No need for two copies.

Installation (using Linux with Python 2.x)

• Install PlatformIO IDE with shell commands or just the core

pip install platformio

see https://platformio.org/install for details

• Install PlatformIO framework espidf for platform espressif32

pio platforms install espressif32 --with-package framework-espidf

• Install ULP toolchain

mkdir -p ~/esp32
cd ~/esp32
wget https://github.com/espressif/binutils-esp32ulp/releases/download/v2.28.51-esp32ulp-20180809/binutils-esp32ulp-linux64-2.28.51-esp32ulp-20180809.tar.gz
tar xzf binutils-esp32ulp-linux64-2.28.51-esp32ulp-20180809.tar.gz

Check for updates at https://github.com/espressif/binutils-esp32ulp/releases/latest)

• Configure environment for the ESP-IDF

echo 'export IDF_PATH=$HOME/.platformio/packages/framework-espidf' >~/esp32/env.sh
echo 'export PATH=$IDF_PATH/bin:$IDF_PATH/../toolchain-xtensa32/bin:$PATH' >>~/esp32/env.sh
echo 'export PATH=~/esp32/esp32ulp-elf-binutils/bin:$PATH' >>~/esp32/env.sh

Best to add this to your ~/.profile

. ~/esp32/env.sh

Build - Flash - Monitor

• Prepare shell to use ESP-IDF (if not done by your .profile already)

. ~/esp32/env.sh

• Fetch and build this example, flash it and open serial console (adapt ESPPORT and ESPBAUD to your setup. Can be configured in sdkconfig file)

mkdir /tmp/blink-$$ && \
cd /tmp/blink-$$ && \
git clone https://github.com/joba-1/Blink-ULP.git && \
cd Blink-ULP && \
make -j8 flash monitor ESPPORT=/dev/ttyUSB0 ESPBAUD=115200

A led connected to gnd (kathode) and gpio2 (anode) should blink now.

Exit the monitor with [Ctrl]-] (which is [Strg]-[Alt-Gr]-] on german keyboard)

Other make targets

Just build the app

I use this for auto build in eclipse

make app

Build the app and flash it, but not config or bootloader

A bit faster and usually enough after the first flash

make app-flash

List all the other possibilities

make help

JoBa1