a183425e00
This implements AudioOut, with known caveats: * pause/resume are not yet implemented (this is just a bug) * at best, the sample fidelity is 8 bits (this is a hardware limitation) Testing performed: My test system is a Particle Xenon with a PAM8302 op-amp https://www.adafruit.com/product/2130 and 8-ohm speaker. There's no analog filtering between the Xenon's PWM pin and the "A+" input of the amplifier; the "A-" pin is disconnected. It is powered from VUSB. I used pin D4, which is *NOT* listed as a low-speed-only pin, but the code does NOT switch the pin to high drive. This is related to an open issue for general inability to set drive level for pins being used by a "special function" on nrf: https://github.com/adafruit/circuitpython/issues/1270 Nothing about the code I've written should limit the usable pins. All samples I played were 16-bit, generally monophonic at 11025Hz and 22050Hz from the Debian LibreOffice package. |
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|---|---|---|
| .. | ||
| bluetooth | ||
| boards | ||
| common-hal | ||
| device/nrf52 | ||
| examples | ||
| freeze | ||
| nrfx@3d268263be | ||
| peripherals/nrf | ||
| supervisor | ||
| .gitignore | ||
| background.c | ||
| background.h | ||
| fatfs_port.c | ||
| gccollect.c | ||
| Makefile | ||
| mpconfigport.h | ||
| mpconfigport.mk | ||
| mphalport.c | ||
| mphalport.h | ||
| nrfx_config.h | ||
| nrfx_glue.h | ||
| nrfx_log.h | ||
| qstrdefsport.h | ||
| README.md | ||
| sd_mutex.c | ||
| sd_mutex.h | ||
| tick.c | ||
| tick.h | ||
CircuitPython Port To The Nordic Semiconductor nRF52 Series
This is a port of CircuitPython to the Nordic Semiconductor nRF52 series of chips.
Supported Features
- UART
- SPI
- LEDs
- Pins
- ADC
- I2C
- PWM
- Temperature
- RTC (Real Time Counter. Low-Power counter)
- BLE support including:
- Peripheral role
- Scanner role
- REPL over Bluetooth LE (optionally using WebBluetooth)
- ubluepy: Bluetooth LE module for CircuitPython
- 1 non-connectable advertiser while in connection
Tested Hardware
- nRF52840
Board Specific Instructions
For board-specific instructions on building and flashing CircuitPython, see the following links:
Note
: These board specific readmes may be more up to date than the generic board-neutral documentation further down.
- Adafruit Feather nRF52840:
boards/feather_nrf52840_express/README.md: 1MB Flash, 256KB SRAM - Nordic PCA10056 (uses nRF52840):
boards/pca10056/README.md - MakerDiary nRF52840 MDK:
boards/makerdiary_nrf52840_mdk/README.md - MakerDiary nRF52840 MDK USB Dongle:
boards/makerdiary_nrf52840_mdk_usb_dongle/README.md
For all other board targets, see the generic notes below.
Compile and Flash
Prerequisite steps for building the nrf port:
git clone <URL>.git circuitpython
cd circuitpython
git submodule update --init
make -C mpy-cross
To build and flash issue the following command inside the ports/nrf/ folder:
make BOARD=pca10056
make BOARD=pca10056 flash
Compile and Flash with Bluetooth Stack
First prepare the bluetooth folder by downloading Bluetooth LE stacks and headers:
./bluetooth/download_ble_stack.sh
If the Bluetooth stacks has been downloaded, compile the target with the following command:
make BOARD=pca10040 SD=s132
The make sd will trigger a flash of the bluetooth stack before that application is flashed. Note that make sd will perform a full erase of the chip, which could cause 3rd party bootloaders to also be wiped.
make BOARD=pca10040 SD=s132 sd
Note: further tuning of features to include in bluetooth or even setting up the device to use REPL over Bluetooth can be configured in the bluetooth_conf.h.
Target Boards and Make Flags
| Target Board (BOARD) | Bluetooth Stack (SD) | Bluetooth Support | Flash Util |
|---|---|---|---|
| pca10056 | s140 | Peripheral and Scanner | Segger |
| feather_nrf52840_express | s140 | Peripheral and Scanner | UF2 bootloader |
| makerdiary_nrf52840_mdk | s140 | Peripheral and Scanner | pyocd or ARM mbed DAPLink |
| makerdiary_nrf52840_mdk_usb_dongle | s140 | Peripheral and Scanner | DFU bootloader & nrfutil |
| electronut_labs_papyr | s140 | Peripheral and Scanner | UF2 bootloader |
| electronut_labs_blip | s140 | Peripheral and Scanner | Black Magic Probe |
Segger Targets
Install the necessary tools to flash and debug using Segger:
note: On Linux it might be required to link SEGGER's libjlinkarm.so inside nrfjprog's folder.
DFU Targets
run follow command to install adafruit-nrfutil from PyPi
$ pip3 install --user adafruit-nrfutil
make flash and make sd will not work with DFU targets. Hence, dfu-gen and dfu-flash must be used instead.
- dfu-gen: Generates a Firmware zip to be used by the DFU flash application.
- dfu-flash: Triggers the DFU flash application to upload the firmware from the generated Firmware zip file.
Example on how to generate and flash feather_nrf52840 target:
make BOARD=feather_nrf52840 SD=s140
make BOARD=feather_nrf52840 SD=s140 dfu-gen dfu-flash
Bluetooth LE REPL
The port also implements a BLE REPL driver. This feature is disabled by default, as it will deactivate the UART REPL when activated. As some of the nRF devices only have one UART, using the BLE REPL free's the UART instance such that it can be used as a general UART peripheral not bound to REPL.
The configuration can be enabled by editing the bluetooth_conf.h and set MICROPY_PY_BLE_NUS to 1.
When enabled you have different options to test it:
- NUS Console for Linux (recommended)
- WebBluetooth REPL (experimental)
Other:
- nRF UART application for IPhone/Android
WebBluetooth mode can also be configured by editing bluetooth_conf.h and set BLUETOOTH_WEBBLUETOOTH_REPL to 1. This will alternate advertisement between Eddystone URL and regular connectable advertisement. The Eddystone URL will point the phone or PC to download WebBluetooth REPL (experimental), which subsequently can be used to connect to the Bluetooth REPL from the PC or Phone browser.