mch22
Warning
This module is only available on the MCH2022 badge, only use this module if you plan to use hardware features specific to the MCH2022 badge.FPGA
The ICE40UP5K FPGA on the MCH2022 badge can be controlled using these APIs.
Loading a bitstream
A bitstream can be loaded into the FPGA by calling mch22.fpga_load(x) with x being a bytes object containing the bitstream binary. Loading a bitstream automatically enables the FPGA.
Disabling the FPGA
To disable the FPGA after a bitstream was loaded call mch22.fpga_disable(). Note that to enable the FPGA a bitstream has to be loaded in again.
Communicating with the FPGA
The FPGA is connected to the ESP32 via an SPI bus. Communication over SPI can be done in full-duplex mode (sending while receiving) or in half-duplex mode (only sending or receiving).
The transmitting functions require a bytes object, the receiving functions return a bytes object.
| Function | Direction | Bus speed |
|---|---|---|
| transaction | Full-duplex | 26.7MHz |
| receive | Read from FPGA | 40MHz |
| send | Write to FPGA | 40MHz |
| send_turbo | Write to FPGA | 40MHz |
In case you get communication errors please check the timing constraints of your bitstream.
LCD mode
To connect the LCD to the FPGA call mch22.lcd_mode(True), to connect the LCD to the ESP32 call mch22.lcd_mode(False). To send the contents of the framebuffer to the LCD call display.flush(True), the True argument forces the flush to happen even though the contents of the framebuffer haven’t changed.
GPIO
You can set the direction of a GPIO pin using mch22.set_gpio_dir(pin, direction), where pin is one of mch22.SAO_IO0_PIN, mch22.SAO_IO1_PIN, mch22.PROTO_0_PIN or mch2022.PROTO_1_PIN and direction is False for input or True for output.
Inputs can be read using value = mch22.get_gpio_value(pin) and outputs can be set using mch22.set_gpio_value(pin, value).
Deprecated functions
These functions have been moved to other, more generic APIs. Please use those APIs instead.
Buttons
The mch22 module exposes a direct interface to the button handler code via the buttons and set_handler functions. Please do not use these, use the buttons API instead. Using these APIs directly can cause crashes to occur.
Brightness control
Please use the display API instead, brightness can be set using display.brightness(x) with x being a value from 0 to 255.