First of all the various methods from the official docs
LED.intensity([value])
Get or set the LED intensity. Intensity ranges between 0 (off) and 255 (full on). If no argument is given, return the LED intensity. If an argument is given, set the LED intensity and return None.
Note: Only LED(3) and LED(4) can have a smoothly varying intensity, and they use timer PWM to implement it. LED(3) uses Timer(2) and LED(4) uses Timer(3). These timers are only configured for PWM if the intensity of the relevant LED is set to a value between 1 and 254. Otherwise the timers are free for general purpose use.
LED.off()
Turn the LED off.
LED.on()
Turn the LED on, to maximum intensity.
LED.toggle()
Toggle the LED between on (maximum intensity) and off. If the LED is at non-zero intensity then it is considered “on” and toggle will turn it off.
This is a simple very short code example in which we show how to create a basic I2CScanner in Micropython using the uPyCraft IDE for a Pyboard
The arduino equivalent is one that I use frequently and is one of the most useful sketches for figuring out why a sensor may not be working correctly with a library or code – usually because the default I2C address differs from the sensor address that you buy
In this example we look at the STM32F4DISCOVERY and in particular the STM32F407G-DISC1
Lets look at some key features
The STM32F4DISCOVERY kit leverages the capabilities of the STM32F407 high performance microcontrollers, to allow users to easily develop applications featuring audio.
It includes an ST-LINK embedded debug tool, one ST-MEMS digital accelerometer, a digital microphone, one audio DAC with integrated class D speaker driver, LEDs, push-buttons and an USB OTG micro-AB connector.
With the latest board enhancement, the new order code STM32F407G-DISC1 has replaced the old reference STM32F4DISCOVERY.
Key Features
STM32F407VGT6 microcontroller featuring 32-bit ARM®Cortex®-M4 with FPU core, 1-Mbyte Flash memory, 192-Kbyte RAM in an LQFP100 package
On-board ST-LINK/V2 on STM32F4DISCOVERY (old reference) or ST-LINK/V2-A on STM32F407G-DISC1 (new order code)
USB ST-LINK with re-enumeration capability and three different interfaces:
Debug port
Virtual Com port (with new order code only)
Mass storage (with new order code only)
Board power supply: through USB bus or from an external 5 V supply voltage
External application power supply: 3 V and 5 V
LIS302DL or LIS3DSH ST MEMS 3-axis accelerometer
MP45DT02 ST-MEMS audio sensor omni-directional digital microphone
CS43L22 audio DAC with integrated class D speaker driver
Eight LEDs:
LD1 (red/green) for USB communication
LD2 (red) for 3.3 V power on
Four user LEDs, LD3 (orange), LD4 (green), LD5 (red) and LD6 (blue)
2 USB OTG LEDs LD7 (green) VBUS and LD8 (red) over-current
Two push-buttons (user and reset)
USB OTG FS with micro-AB connector
Extension header for all LQFP100 I/Os for quick connection to prototyping board and easy probing
Comprehensive free software including a variety of examples, part of STM32CubeF4 package or STSW-STM32068 to use legacy standard libraries.
There are 4 coloured LEDs on the STM32F407G-DISC1 development board as stated above, these are locate dunder the microcontroller
We used Atom IDE with Platform.IO installed and added support for the STM32 boards. This is an Arduino example (confused). You could add STM32 support to the Arduino IDE by adding stm32duino support but I like the look of Platform IDE so wanted to play about with the IDE
This is a fairly basic example to flash the LEDS off and on repeatedly
#include <Arduino.h>void setup(){// put your setup code here, to run once:// Set the MCU's pin data direction.
pinMode(PD13, OUTPUT);
pinMode(PD14, OUTPUT);
pinMode(PD15, OUTPUT);
pinMode(PD12, OUTPUT);// Set all outputs LOW to have all LED's initially turned off.
digitalWrite(PD13, LOW);
digitalWrite(PD14, LOW);
digitalWrite(PD15, LOW);
digitalWrite(PD12, LOW);}void loop(){// put your main code here, to run repeatedly:// Turn off the GREEN LED, turn on the ORANGE LED and wait for 1000ms.
digitalWrite(PD12, HIGH);
digitalWrite(PD13, HIGH);
digitalWrite(PD14, HIGH);
digitalWrite(PD15, HIGH);
delay(1000);
digitalWrite(PD12, LOW);
digitalWrite(PD13, LOW);
digitalWrite(PD14, LOW);
digitalWrite(PD15, LOW);
delay(1000);// The code in the "loop()" statement will automatically repeat.}
In this article we look at the Arch from Seeed. Its an MBed compatible board with Arduino headers fitted and is reasonably low cost
Features
NXP LPC11U24 MCU
Low power ARM Cortex-M0 Core
48MHz, 32KB Flash, 8KB RAM, 4KB EEPROM
USB Device, 2xSPI, UART, I2C
Here is a pinout of the Arch
Code
Some simple flashy LED examples that use the mbed online compiler
To program the device you do the following
The button of Arch is specially designed to provide two functions:
Quick press to reset
Long press to enter USB ISP mode, a CRP DISABLD disk will pop up.
On Windows, replace firmware.bin with your program binary file generated from the MBed compiler
Another VEML sensor, this time its a VEML6075 and again we connect it to an Arduino Due
The VEML6075 senses UVA and UVB light and incorporates photodiode, amplifiers, and analog / digital circuits into a single chip using a CMOS process. When the UV sensor is applied, it is able to detect UVA and UVB intensity to provide a measure of the signal strength as well as allowing for UVI measurement.
The VEML6075 provides excellent temperature compensation capability for keeping the output stable under changing temperature. VEML6075’s functionality is easily operated via the simple command format of I2C (SMBus compatible) interface protocol. VEML6075’s operating voltage ranges from 1.7 V to 3.6 V.
#include <Wire.h>#include "Adafruit_VEML6075.h"
Adafruit_VEML6075 uv = Adafruit_VEML6075();void setup(){
Serial.begin(115200);
Serial.println("VEML6075 Full Test");if(! uv.begin()){
Serial.println("Failed to communicate with VEML6075 sensor, check wiring?");}
Serial.println("Found VEML6075 sensor");// Set the integration constant
uv.setIntegrationTime(VEML6075_100MS);// Get the integration constant and print it!
Serial.print("Integration time set to ");switch(uv.getIntegrationTime()){case VEML6075_50MS: Serial.print("50");break;case VEML6075_100MS: Serial.print("100");break;case VEML6075_200MS: Serial.print("200");break;case VEML6075_400MS: Serial.print("400");break;case VEML6075_800MS: Serial.print("800");break;}
Serial.println("ms");// Set the high dynamic mode
uv.setHighDynamic(false);// Get the modeif(uv.getHighDynamic()){
Serial.println("High dynamic reading mode");}else{
Serial.println("Normal dynamic reading mode");}// Set the mode
uv.setForcedMode(false);// Get the modeif(uv.getForcedMode()){
Serial.println("Forced reading mode");}else{
Serial.println("Continuous reading mode");}// Set the calibration coefficients
uv.setCoefficients(2.22, 1.33, // UVA_A and UVA_B coefficients2.95, 1.74, // UVB_C and UVB_D coefficients
0.001461, 0.002591);// UVA and UVB responses}void loop(){
Serial.print("Raw UVA reading: "); Serial.println(uv.readUVA());
Serial.print("Raw UVB reading: "); Serial.println(uv.readUVB());
Serial.print("UV Index reading: "); Serial.println(uv.readUVI());
delay(1000);}
Output
Open the serial monitor – this is what I saw but I tested this indoors
VEML6075 Full Test
Failed to communicate with VEML6075 sensor, check wiring?
Found VEML6075 sensor
Integration time set to 50ms
Normal dynamic reading mode
Continuous reading mode
Raw UVA reading: 0.00
Raw UVB reading: 0.00
UV Index reading: 0.00
Raw UVA reading: 0.00
Raw UVB reading: 0.00
UV Index reading: 0.00
