According to the schematic, the SDRAM part on this board is a
MT48LC4M32B2B5-6A, with "Row addressing 4K A[11:0]" (per datasheet). This
commit updates mpconfigboard.h from 13 to 12 to match.
- STM32F407VGT6 (1MB of Flash, 192+4 Kbytes of SRAM)
- 5V (via USB) or Li-Polymer Battery (3.7V) power input
- 2 x LEDs
- 2 x user switches
- 2 x mikroBUS sockets
- 2 x 1x26 mikromedia-compatible headers (52 pins)
https://www.mikroe.com/clicker-2-stm32f4
Mboot currently requires at least three LEDs to display each of the four
states. However, since there are only four possible states, the states can
be displayed via binary counting on only 2 LEDs (if only 2 are available).
The existing patterns are still used for 3 or 4 LEDs.
As per PEP 485, this function appeared in for Python 3.5. Configured via
MICROPY_PY_MATH_ISCLOSE which is disabled by default, but enabled for the
ports which already have MICROPY_PY_MATH_SPECIAL_FUNCTIONS enabled.
Before this patch I2C transactions using a hardware I2C peripheral on F0/F7
MCUs would not correctly generate the I2C restart condition, and instead
would generate a stop followed by a start. This is because the CR2 AUTOEND
bit was being set before CR2 START when the peripheral already had the I2C
bus from a previous transaction that did not generate a stop.
As a consequence all combined transactions, eg read-then-write for an I2C
memory transfer, generated a stop condition after the first transaction and
didn't generate a stop at the very end (but still released the bus). Some
I2C devices require a repeated start to function correctly.
This patch fixes this by making sure the CR2 AUTOEND bit is set after the
start condition and slave address have been fully transferred out.
Some SD/MMC breakout boards don't support 4-bit bus mode. This adds a new
macro MICROPY_HW_SDMMC_BUS_WIDTH that allows each board to define the width
of the SD/MMC bus interface used on that board, defaulting to 4 bits.
The previous version did not work on MCUs that only had USB device mode
(compared to OTG) because of the handling of NAK. And this previous
handling of NAK had a race condition where a new packet could come in
before USBD_HID_SetNAK was called (since USBD_HID_ReceivePacket clears NAK
as part of its operation). Furthermore, the double buffering of incoming
reports was not working, only one buffer could be used at a time.
This commit rewrites the HID interface code to have a single incoming
buffer, and only calls USBD_HID_ReceivePacket after the user has read the
incoming report (similar to how the VCP does its flow control). As such,
USBD_HID_SetNAK and USBD_HID_ClearNAK are no longer needed.
API functionality from the user's point of view should be unchanged with
this commit.
This new series of MCUs is similar to the L4 series with an additional
Cortex-M0 coprocessor. The firmware for the wireless stack must be managed
separately and MicroPython does not currently interface to it. Supported
features so far include: RTC, UART, USB, internal flash filesystem.
