I was trying to get an ESP32 working with I2C and because I had it around I took a MCP23009. Schmeantic is in the Image Image
My Code is the following :
#include <Wire.h> // specify use of Wire.h library.
#define MCPAddress 0x20 //I2C Address
#define IO_DIR_REG 0x00 // The Output Register
#define GPIO_REG 0x09 // The GPIO Register
#define IOCON 0x05 // Settings
#define SEQOP_REQ 0b00100000 // Disable address increment
#define I2C_SDA 21
#define I2C_SCL 22
int error;
void setup()
{
Serial.begin(115200);
delay(1000);
Serial.println("Starting Wire");
Wire.begin(I2C_SDA, I2C_SCL);
Wire.setClock(100000); //Frequenz
Wire.beginTransmission(MCPAddress); // Check if connection succesfull
error = Wire.endTransmission();
if(error == 0){
Serial.println("Success");
}else{
Serial.println("Failure: ");
Serial.print(error);
}
//Serial.println("Disable Auto-Address increment!");
//writeBlockData(IOCON,SEQOP_REQ); //Experimental, didn't make it work
Serial.println("Setting Outputs!");
writeBlockData(IO_DIR_REG,0x00);
Serial.println("Writing LOW!");
writeBlockData(GPIO_REG,0x00);
}
void loop()
{
Serial.println("Writing HIGH!");
writeBlockData(GPIO_REG,0b11111111);
delay(3000);
Serial.println("Writing LOW!");
writeBlockData(GPIO_REG,0b00000000);
delay(3000);
}
int writeBlockData(uint8_t cmd, uint8_t val)
{
Wire.beginTransmission(MCPAddress);
Wire.write(cmd);
Wire.write(val);
delay(10);
return Wire.endTransmission();
}
It's fairly simple and the connections works as I get only 0 when I read Wire.endTransmission() but the LEDs never turn High. No matter what I do. Here is the Datasheet from the MCP http://ww1.microchip.com/downloads/en/DeviceDoc/20002121C.pdf
If anybody sees my mistake I would really appreciate it ! I am fairly new to work with I2C so I dont really see it. Even working with a Arduino Library didnt work.
Thanks and greetings !
Well, I didn' read the whole datasheet. The MCP has open drain outputs so turning around the diodes and put the other end into Vdd fixed it.
Related
experts.
I am new to STM32.
So I downloaded some sample code from github.
https://github.com/yohanes-erwin/stm32f103-keil
And I download the simple led blinking code of it to the STM32F103C6 developing board but it doesn't work at all.
The original program embedded on the chip had been erased successfully ( originally the led was always on and LCD screen shows some text, but now after I download the code, the led is off and screen off. So I think the downloading is successful.) but the code does not work.
When I download the original code to the chip, it works again. So I think the chip isn't broken.
I think it's because of compatibility of sample code and my chip. The sample code was written for STM32F103C8. But it was a very simple code. What is the reason?
Here is the code.
#include "stm32f10x.h"
#include "stm32f10x_rcc.h"
#include "stm32f10x_gpio.h"
void delay(unsigned int nCount);
GPIO_InitTypeDef GPIO_InitStruct;
int main (void)
{
// Enable clock for GPIOA
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
// Configure PA4 as push-pull output
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_4;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_2MHz;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_Init(GPIOA, &GPIO_InitStruct);
while (1)
{
/* Toggle LED on PA0 */
// Reset bit will turn on LED (because the logic is interved)
GPIO_ResetBits(GPIOA, GPIO_Pin_4);
delay(1000);
// Set bit will turn off LED (because the logic is interved)
GPIO_SetBits(GPIOA, GPIO_Pin_4);
delay(1000);
}
}
// Delay function
void delay(unsigned int nCount)
{
unsigned int i, j;
for (i = 0; i < nCount; i++)
for (j = 0; j < 0x2AFF; j++);
}
So, I am trying to toggle a LED based on an interrupt from a button.
Ideally the when the button is pressed the LED should toggle i.e. switch on if its off and vice versa. But when I execute this code it toggles and returns to its original state.
Expected Result:
LED OFF » Button pressed » LED ON
Practical Result:
LED OFF » Button pressed » LED ON » LED OFF
I have added a delay for debouncing so bouncing is out of the picture. Also the GPIO's ODR is set in the ISR when the button is pressed so how is it getting cleared while exiting the ISR?
I would really appreciate your help! Thank you.
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/gpio.h>
#include <libopencm3/stm32/exti.h>
#include <libopencm3/cm3/nvic.h>
#define LEDPIN (GPIO13)
static void exti_setup(void)
{
/* Enable GPIOA and AFIO clock. */
rcc_periph_clock_enable(RCC_GPIOB);
rcc_periph_clock_enable(RCC_AFIO);
/* Enable EXTI0 interrupt. */
nvic_enable_irq(NVIC_EXTI15_10_IRQ);
/* Set GPIO12 (in GPIO port B) to input */
gpio_set_mode(GPIOB, GPIO_MODE_INPUT,GPIO_CNF_INPUT_FLOAT, GPIO12);
/* Configure the EXTI subsystem. */
exti_select_source(EXTI12,GPIOB);
exti_set_trigger(EXTI12, EXTI_TRIGGER_BOTH);
exti_enable_request(EXTI12);
}
static void gpio_setup(void)
{
/* Enable clock for GPIO port C */
rcc_periph_clock_enable(RCC_GPIOC);
/* Set LEDPIN (in GPIO port C) as opendrain output */
gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, LEDPIN);
}
void delay(){
int i;
for (i = 0; i < 1000000; i++)
{
__asm__("nop");
}
}
void handler(){
delay();
gpio_toggle(GPIOC, GPIO13);
}
int main(void)
{
gpio_setup();
exti_setup();
while (1) {
__asm__("nop");
}
return 0;
}
void exti15_10_isr()
{
exti_reset_request(EXTI12);
handler();
}
Not open drain but push-pull
Butttons should not use EXTI as it makes debouncing more complicated, often floods the uC with interrupts, Use timer interrupt instead to read the key and debounce.
As #dev_eng rightly pointed out the issue was the interrupt being configured as both RISING/FALLING edge.
Configuring it with single EDGE that is either RISING or FALLING solved my problem.
I am trying to set up a communication between my STM32F4 - Discovery with Open 407V-D development board and a peripheral using UART3 as a RS-485 bus.
I have problem with my communication becouse Rx state of UART remain busy.
Could somebody please explain me what am I doing wrong?
Should I somehow edit HAL_UART_IRQHandler or what setting am I missing?
Here is my code:
#include "main.h"
#include "stm32f4xx_hal.h"
UART_HandleTypeDef huart3;
uint8_t Ocular_1_RxBuffer[4];
uint8_t Ocular_1_TxBuffer[2] = {0x01,0x86};
__IO ITStatus UartReady;
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART3_UART_Init(void);
int main(void)
{
HAL_Init();
SystemClock_Config();
MX_GPIO_Init();
MX_USART3_UART_Init();
HAL_GPIO_WritePin(GPIOB,GPIO_PIN_9,GPIO_PIN_SET); //set RS 485 into transmit mode
while (1)
{
int Timeout = 1000000;
while(huart3.gState != HAL_UART_STATE_READY) //wait for UART
{
Timeout--;
if(Timeout == 0)
Error_Handler();
}
Timeout = 1000000;
if(HAL_UART_Transmit_IT(&huart3, (uint8_t*)Ocular_1_TxBuffer, 2) != HAL_OK) //Send request
{
Error_Handler();
}
while(huart3.RxState != HAL_UART_STATE_READY) //wait for UART
{
Timeout--;
if(Timeout == 0)
Error_Handler();
}
Timeout = 1000000;
if(HAL_UART_Receive_IT(&huart3, (uint8_t*)Ocular_1_RxBuffer, 4) != HAL_OK) //Response
{
Error_Handler();
}
while(UartReady == RESET) //Wait for response
{
Timeout--;
if(Timeout == 0)
Error_Handler();
}
}
}
I have successfully received response from my peripheral device, but my code generate Error_Handler() after HAL_UART_RxCpltCallback() function.
Could somebody please explain this behavior to me?
My callback functions:
void HAL_UART_TxCpltCallback(UART_HandleTypeDef *UartHandle)
{
/* Set transmission flag: transfer complete */
HAL_GPIO_WritePin(GPIOB,GPIO_PIN_9,GPIO_PIN_RESET);
UartReady = RESET;
}
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *UartHandle)
{
/* Set transmission flag: transfer complete */
HAL_GPIO_WritePin(GPIOB,GPIO_PIN_9,GPIO_PIN_SET);
UartReady = SET;
}
Please mention the number of bytes you are receiving in current scenario.?
Some debugging tips are -
Try increasing the size of your buffer and check if you are receiving any data.
Make sure you are re initialising your buffer after 4 bytes are read. If not the buffer can overflow and may lead to error handler.
Make sure you transmitter always sends 4 bytes.
Confirm if your buad rate matches on both devices. Also settings like parity and all are same in receiver and transmitter.
After every 4 bytes you need to call the HAL_UART_Receive_IT() again to configure and wait for next interrupt.
Add Error callback too, and confirm if execution moves to this callback. If then add prints in driver to find out whats the error cause, whether its like overrun error / Noise error / Parity Error etc.
I have the STM32F0DISCOVERY Board with the STM32F051R8T6 microcontroller. I am trying to communicate to the PC using USART.
Sending data from the board to the PC works fine with my putChar() function.
Receiving data sent from the PC to the board with my getChar() function is not working properly. The problem is that the RXNE flag (Read Data Register Not Empty) is not being set. However I have seen using the debugger in Keil uVision4 that the data is indeed in RDR (Receive Data Register).
I have tried running it without debugging, just in case the debugger was reading the RDR register before my program could read the RXNE flag and it's still not working.
This is my code:
#include <STM32F0xx.h>
uint8_t data;
int main (void) {
RCC->AHBENR |= (1UL<<17); // PortA clock enable
GPIOA->MODER &= ~((3UL<<2*2)|(3UL<<2*3));
GPIOA->MODER |= ((2UL<<2*2)|(2UL<<2*3)); // Alt func on PA2, PA3
GPIOA->AFR[0] &= ~((15UL<<4*2)|(15UL<<4*2));
GPIOA->AFR[0] |= (( 1UL<<4*2)|( 1UL<<4*3)); // Alt func 1 on PA2, PA3
RCC->APB1ENR |= (1UL<<17); // USART clock enable
USART2->BRR = 5000; // Baud rate 48 000 000 / BRR -> 9600
USART2->CR1 |= (1UL<<0); // Enable USART
while (1) {
data = getChar();
if (data!=0xFF) {
putChar(data);
}
}
}
Here is the putChar() function that works properly.
void putChar (uint8_t data) {
USART2->CR1 |= (1UL<<3); // Transmitter enable
USART2->TDR = data;
while ((USART2->ISR|(1UL<<7))==(1UL<<7)); // Wait until sent
}
Here is the getChar() function that is not working and keeps returning 0xFF.
uint8_t getChar (void) {
USART2->CR1 |= (1UL<<2); // Receiver enable
if ((USART2->ISR|(1UL<<5))==(1UL<<5)) { // Check RXNE to see if there is data
return USART2->RDR;
} else {
return 0xFF;
}
}
You are not correctly checking the RXNE bit. This line of your code is wrong:
if ((USART2->ISR|(1UL<<5))==(1UL<<5)) {
You need to use an AND instead of an OR. This will allow you to mask correctly and check if the bit is set. Use this instead:
if ((USART2->ISR&(1UL<<5))==(1UL<<5)) {
In this you are checking the default state of the bit.
Check it and put your code in else if the data is there if no data then it goes in if condition.
if ((USART2->ISR&(1UL<<5))==(1UL<<5)) {
} else {
/***** operations *****/
}
Currently I am trying to get a sketch working where the Arduino will read a series of characters as a command, and do something based on the series of characters sent from an iDevice. I am using an iPhone 3GS that is jailbroken to send characters to the Arduino. The method that sends the serial characters looks like the following,
- (IBAction)blinkFlow_A_LED:(id)sender {
// Method to blink the Flow_A LED on the kegboard-mini Arduino shield (<https://github.com/Kegbot/kegboard>).
NSLog(#"blink Flow_A btn pressed");
// Open serial port / interface
[serial open:B2400];
NSLog(#"%c", [serial isOpened]);
// Send serial data (TX)
char buffer [7];
buffer[0] = '{';
buffer[1] = 'b';
buffer[2] = 'l';
buffer[3] = 'i';
buffer[4] = 'n';
buffer[5] = 'k';
buffer[6] = '}';
[serial write:buffer length:7];
}
I have created a simple sketch that blinks the LED on the shield I am using, but I want the LED to blink conditionally when the button is clicked in the iOS app. The sketch that blinks the LED looks like the following,
/*
Blink
Turns on an LED on for one second, then off for one second, repeatedly.
This sketch is specific to making the kegboard-mini shield.
http://arduino.cc/forum/index.php?topic=157625.new;topicseen#new
This example code is in the public domain.
*/
// Pin D4 - should be connected to the flow_A LED
// Give it a name
int led = 4;
// The setup routine runs once when you press reset:
void setup() {
// Initialize the digital pin as an output.
pinMode(led, OUTPUT);
}
// The loop routine run over and over again forever:
void loop() {
digitalWrite(led, HIGH); // Turn the LED on (HIGH is the voltage level)
delay(1000); // Wait for one second
digitalWrite(led, LOW); // Turn the LED off by making the voltage LOW
delay(1000); // Wait for a second
}
That is a simple sketch!
You may want to begin with looking at the Arduino reference page: Serial
In setup(), you need at least Serial.begin(2400);.
Now, I'll suggest that reading and decoding the string "{blink}" seems like overkill. Let me suggest you send one character (for example 'b'), and detect one character, at least to start. Check out .available() and .read() on the Serial reference page. With these you can determine if a character has arrived at the Arduino and read in a single character.
You can then use these if you want to build a string of characters one at a time and compare it to String("{blink}"). This is a bit more complicated, especially if you take into account exceptions (like lost or damaged characters).
You can easily test your program using the Serial monitor tool -- just be advised that you have to hit "send" to make the characters go out.
I ended putting a simple sketch together like this which allows me to store an array of serial bytes into a String thanks to the SerialEvent example.
The sketch I am currently working with looks like the following,
/*
* kegboard-serial-simple-blink07
* This code is public domain
*
* This sketch sends a receives a multibyte String from the iPhone
* and performs functions on it.
*
* Examples:
* http://arduino.cc/en/Tutorial/SerialEvent
* http://arduino.cc/en/Serial/read
*/
// Global variables should be identified with "_"
// flow_A LED
int led = 4;
// relay_A
const int RELAY_A = A0;
// Variables from the sketch example
String inputString = ""; // A string to hold incoming data
boolean stringComplete = false; // Whether the string is complete
void setup() {
Serial.begin(2400); // Open a serial port. Sets data rate to 2400 bit/s
Serial.println("Power on test");
inputString.reserve(200);
pinMode(RELAY_A, OUTPUT);
}
void open_valve() {
digitalWrite(RELAY_A, HIGH); // Turn RELAY_A on
}
void close_valve() {
digitalWrite(RELAY_A, LOW); // Turn RELAY_A off
}
void flow_A_blink() {
digitalWrite(led, HIGH); // Turn the LED on (HIGH is the voltage level)
delay(1000); // Wait for one second
digitalWrite(led, LOW); // Turn the LED off by making the voltage LOW
delay(1000); // Wait for a second
}
void flow_A_blink_stop() {
digitalWrite(led, LOW);
}
void loop() {
// Print the string when newline arrives:
if (stringComplete) {
Serial.println(inputString);
// Clear the string:
inputString = "";
stringComplete = false;
}
if (inputString == "{blink_Flow_A}") {
flow_A_blink();
}
}
// SerialEvent occurs whenever a new data comes in the
// hardware serial RX. This routine is run between each
// time loop() runs, so using delay inside loop can delay
// response. Multiple bytes of data may be available.
void serialEvent() {
while(Serial.available()) {
// Get the new byte:
char inChar = (char)Serial.read();
// Add it to the inputString:
inputString += inChar;
// If the incoming character is a newline, set a flag
// so the main loop can do something about it:
if (inChar == '\n') {
stringComplete = true;
}
}
}