This is implemented in inline assembly using machine.CPUFrequency() to
know how long a single CPU cycle takes. As long as it is called with a
constant duration, it should be fully inlined and all values can be
const-propagated resulting in very tight inline assembly.
For example, when I convert i2csoft to use this delay function, the
entire delay function compiles to something like this:
8784: movs r6, #100
8786: mov r0, r6
8788: nop
878a: nop
878c: nop
878e: nop
8790: nop
8792: subs r0, #1
8794: bne 0x8788
That means that all the math to calculate the number of cycles is
entirely optimized away (in this case, to 100 loops).
I ran the example on a few boards to see how well it works:
| board | 100ms wait | CPU core
|-----------------------|------------|------
| microbit | 121.6ms | Cortex-M0 so it has 12% overhead
| circuitplay-express | 100.1ms | Cortex-M0+ so it is cycle accurate
| pico | 100.2ms | Cortex-M0+
| pyportal | 100.3ms | Cortex-M4
| circuitplay-bluefruit | 125.8ms | Cortex-M4
| esp8266 | 125.1ms |
This shows that there is some loop overhead because of conservative
estimates, but note that even though there may be a 25% overhead, the
actual overhead per `delay.Sleep()` call is very small. It should be
good enough for software I2C at least, and can potentially be improved
in the future.
- Remove all default loraconf default initialisation in lorawan examples (Region Settings takes care of this now)
- Remove retries while receiving JoinAccept and increase LoraRX to 10s (no need to wait more than 10s)
- Add constants for RegionSetting default frequencies
- Standardize all lora default configurations in lora examples
- Add new AT+LW=NET,(ON|OFF) command in atcmd example
* wifinina: add support for http server
This adds http.ListenAndServe() implementation for wifinina. Included
is an example webserver, basically copied from the rtl8720dn/webserver.
Tested on Arduino Nano RP2040 Connect. Also tried testing on Arduino
Nano33 IoT but test panics with "out of memory". There's only 32K of
SRAM on the Nano33, vs 264K on the rp2040 Connect.
Currently, easystepper driver supports only '4-step mode' (12-23-34-41) when energizing the coils
This does not work with all motors & drivers (e.g. 28BJY-48 & ULN2003)
This commit adds support for 8-step mode (1-12-2-23-3-34-4-41)
Note: this commit breaks backward source compatibility for the factory/constructor functions.