X-Git-Url: https://vault307.fbx.one/gitweb/micorpython_ir.git/blobdiff_plain/8ac6c4b0b81221439541db8f7bdbab29913da9bb..146e7a81c29ff28c5c81998b52eccb0d23582799:/TRANSMITTER.md?ds=sidebyside diff --git a/TRANSMITTER.md b/TRANSMITTER.md index 2cf169a..2093db7 100644 --- a/TRANSMITTER.md +++ b/TRANSMITTER.md @@ -13,8 +13,14 @@ On the Pyboard the transmitter test script assumes pin X1 for IR output. It can be changed, but it must support Timer 2 channel 1. Pins for pushbutton inputs are arbitrary: X3 and X4 are used. The driver uses timers 2 and 5. -On ESP32 the demo uses pins 21 and 23 for IR output and pins 18 and 19 for -pushbuttons. These pins may be changed. +On ESP32 the demo uses pin 23 for IR output and pins 18 and 19 for pushbuttons. +These pins may be changed. The only device resource used is `RMT(0)`. + +On Raspberry Pi Pico the demo uses pin 17 for IR output and pins 18 and 19 for +pushbuttons. These pins may be changed. The driver uses the PIO to emulate a +device similar to the ESP32 RMT. The device driver is +[documented here](./RP2_RMT.md); this is for experimenters and those wanting to +use the library in conjunction with their own PIO assembler code. ## 1.1 Pyboard Wiring @@ -30,20 +36,22 @@ increase power. The transistor type is not critical. The driver assumes circuits as shown. Here the carrier "off" state is 0V, -which is the driver default. If using a circuit where "off" is required to be -3.3V, the class variable `active_high` should be set `False`. +which is the driver default. If using an alternative circuit where "off" is +required to be 3.3V, the class variable `active_high` should be set `False`. ## 1.2 ESP32 Wiring -The ESP32 RMT device does not currently support the carrier option. A simple -hardware gate is required to turn the IR LED on when both the carrier pin and -the RMT pin are high. A suitable circuit is below; the transistor type is not -critical. -![Image](images/gate.png) +The ESP32 RMT device now supports the carrier option, and this driver has been +updated to use it. The same circuits as above may be used to connect to pin 23 +(or other pin, if the code has been adapted). The `active_high` option is not +available on the ESP32 `RMT` object, so any alternative circuit must illuminate +the LED if the pin state is high. + +## 1.3 RP2 Wiring -This simpler alternative uses MOSFETS, but the device type needs attention. The -chosen type has a low gate-source threshold voltage and low Rdson. -![Image](images/gate_mosfet.png) +There is no `active_high` option so the circuit must illuminate the LED if the +pin state is high, as per the above drivers. Test programs use pin 17, but this +can be reassigned. # 2. Dependencies and installation @@ -51,11 +59,17 @@ chosen type has a low gate-source threshold voltage and low Rdson. The device driver has no dependencies. -On ESP32 a firmware version >= V1.12 is required. The Loboris port is not -supported owing to the need for the RMT device. +On ESP32 a firmware version >= V1.14 is required. The Loboris port is not +supported owing to the need for the RMT device and other issues. -The demo program requires `uasyncio` from the official library and `aswitch.py` -from [this repo](https://github.com/peterhinch/micropython-async). +The demo program uses `uasyncio` primitives from +[this repo](https://github.com/peterhinch/micropython-async). Clone the repo to +a directory on your PC: +```bash +$ git clone https://github.com/peterhinch/micropython-async +``` +move to its `v3` directory, and copy the `primitives` directory with its +contents to the filesystem. ## 2.2 Installation @@ -78,13 +92,36 @@ Instructions will be displayed at the REPL. # 3. The driver -This is specific to Pyboard D, Pyboard 1.x (not Lite) and ESP32. +This is specific to Pyboard D, Pyboard 1.x (not Lite), ESP32 and Raspberry Pi +Pico (RP2 architecture chip). It implements a class for each supported protocol, namely `NEC`, `SONY_12`, `SONY_15`, `SONY_20`, `RC5` and `RC6_M0`. Each class is subclassed from a common abstract base class in `__init__.py`. The application instantiates the appropriate class and calls the `transmit` method to send data. +Basic usage on a Pyboard: +```python +from machine import Pin +from ir_tx.nec import NEC +nec = NEC(Pin('X1')) +nec.transmit(1, 2) # address == 1, data == 2 +``` +Basic usage on ESP32: +```python +from machine import Pin +from ir_tx.nec import NEC +nec = NEC(Pin(23, Pin.OUT, value = 0)) +nec.transmit(1, 2) # address == 1, data == 2 +``` +Basic usage on Pico: +```python +from machine import Pin +from ir_tx.nec import NEC +nec = NEC(Pin(17, Pin.OUT, value = 0)) +nec.transmit(1, 2) # address == 1, data == 2 +``` + #### Common to all classes Constructor args: @@ -253,13 +290,9 @@ transmission by calling the Timer5 callback. ## 4.2 ESP32 -The carrier is output continuously at the specified duty ratio. A pulse train -generated by the RMT instance drives a hardware gate such that the IR LED is -lit only when both carrier and RMT are high. - -The carrier is generated by PWM instance `.pwm` running continuously. The ABC -constructor converts the 0-100 duty ratio specified by the subclass to the -0-1023 range used by ESP32. +The RMT class now supports `carrier_freq` and `carrier_duty_percent` +constructor args, so the base class `IR` (in `__init__.py`) uses these to +enable the OOK (on-off keying) waveform. The `.trigger` method calls `RMT.write_pulses` and returns with `RMT` operating in the background.