Ordered some I2C 7 segment displays off amazon and they did not work even after I removed the caps. Anybody know of a place a good place to get working 0.56 I2C 7 segment displays for a decent price? I need 27 of them and dropping $10-15 a pop just isn't going to work for this project.
thanks for any help.
How did they not work?
27? Remember that with I2C each device on the bus must have its own unique address. Some displays may have jumpers allowing the user to select one of say 8 addresses. There are,however, I2C port multiplexers available which can increase this limit say TCA9548A. You may also have to remove pullup resistors to limit the total load on a bus.
Green power light lit, but the display did not. Tried an ESP32 and an Arduino using the TM1637Display.h library example test code. Used a 5v power supply to apply power to the display.
#include <Arduino.h>
#include <TM1637Display.h>
// Module connection pins (Digital Pins)
#define CLK 2
#define DIO 3
// The amount of time (in milliseconds) between tests
#define TEST_DELAY 2000
const uint8_t SEG_DONE[] = {
SEG_B | SEG_C | SEG_D | SEG_E | SEG_G, // d
SEG_A | SEG_B | SEG_C | SEG_D | SEG_E | SEG_F, // O
SEG_C | SEG_E | SEG_G, // n
SEG_A | SEG_D | SEG_E | SEG_F | SEG_G // E
};
TM1637Display display(CLK, DIO);
void setup()
{
}
void loop()
{
int k;
uint8_t data[] = { 0xff, 0xff, 0xff, 0xff };
uint8_t blank[] = { 0x00, 0x00, 0x00, 0x00 };
display.setBrightness(0x0f);
// All segments on
display.setSegments(data);
delay(TEST_DELAY);
// Selectively set different digits
data[0] = display.encodeDigit(0);
data[1] = display.encodeDigit(1);
data[2] = display.encodeDigit(2);
data[3] = display.encodeDigit(3);
display.setSegments(data);
delay(TEST_DELAY);
/*
for(k = 3; k >= 0; k--) {
display.setSegments(data, 1, k);
delay(TEST_DELAY);
}
*/
display.clear();
display.setSegments(data+2, 2, 2);
delay(TEST_DELAY);
display.clear();
display.setSegments(data+2, 2, 1);
delay(TEST_DELAY);
display.clear();
display.setSegments(data+1, 3, 1);
delay(TEST_DELAY);
// Show decimal numbers with/without leading zeros
display.showNumberDec(0, false); // Expect: ___0
delay(TEST_DELAY);
display.showNumberDec(0, true); // Expect: 0000
delay(TEST_DELAY);
display.showNumberDec(1, false); // Expect: ___1
delay(TEST_DELAY);
display.showNumberDec(1, true); // Expect: 0001
delay(TEST_DELAY);
display.showNumberDec(301, false); // Expect: _301
delay(TEST_DELAY);
display.showNumberDec(301, true); // Expect: 0301
delay(TEST_DELAY);
display.clear();
display.showNumberDec(14, false, 2, 1); // Expect: _14_
delay(TEST_DELAY);
display.clear();
display.showNumberDec(4, true, 2, 2); // Expect: 04__
delay(TEST_DELAY);
display.showNumberDec(-1, false); // Expect: __-1
delay(TEST_DELAY);
display.showNumberDec(-12); // Expect: _-12
delay(TEST_DELAY);
display.showNumberDec(-999); // Expect: -999
delay(TEST_DELAY);
display.clear();
display.showNumberDec(-5, false, 3, 0); // Expect: _-5_
delay(TEST_DELAY);
display.showNumberHexEx(0xf1af); // Expect: f1Af
delay(TEST_DELAY);
display.showNumberHexEx(0x2c); // Expect: __2C
delay(TEST_DELAY);
display.showNumberHexEx(0xd1, 0, true); // Expect: 00d1
delay(TEST_DELAY);
display.clear();
display.showNumberHexEx(0xd1, 0, true, 2); // Expect: d1__
delay(TEST_DELAY);
// Run through all the dots
for(k=0; k <= 4; k++) {
display.showNumberDecEx(0, (0x80 >> k), true);
delay(TEST_DELAY);
}
// Brightness Test
for(k = 0; k < 4; k++)
data[k] = 0xff;
for(k = 0; k < 7; k++) {
display.setBrightness(k);
display.setSegments(data);
delay(TEST_DELAY);
}
// On/Off test
for(k = 0; k < 4; k++) {
display.setBrightness(7, false); // Turn off
display.setSegments(data);
delay(TEST_DELAY);
display.setBrightness(7, true); // Turn on
display.setSegments(data);
delay(TEST_DELAY);
}
// Done!
display.setSegments(SEG_DONE);
while(1);
}
It will be 9 on 3 different ESP 32. I have parts to make 3 of them.
building this project:
@phil570 -
Instructions found here:
https://dronebotworkshop.com/multiple-i2c-bus/
Note that the TM1637 is not an I2C chip. It may, however, be compatible with the port expanders already mentioned.
But it looks like you have other problems. Where did you see a recommendation to remove capacitors ?
I found a few places it was mentioned with the amazon displays
Diagram of the build here. He is not using any else than the ESP32 and display.
I shouldn't have said I2C it is not using that protocol. The TM-1637 just allows for a 2 wire interface with the 7 segment displays.
Creators code for the project:
#include "Arduino.h"
#include "TM1637Display.h"
#include "ArduinoJson.h"
#include "DNSServer.h"
#include "NTPClient.h"
#include "WiFiManager.h"
#include "WiFiUdp.h"
// Module connection pins (Digital Pins)
#define red_CLK 13
#define red1_DIO 14
#define red2_DIO 15
#define red3_DIO 16
#define green_CLK 17
#define green1_DIO 18
#define green2_DIO 19
#define green3_DIO 21
#define orange_CLK 22
#define orange1_DIO 23
#define orange2_DIO 25
#define orange3_DIO 26
#define greenAM 32
#define greenPM 33
bool res;
//========================USEFUL VARIABLES=============================
const long utcOffsetInSeconds = -14400; // UTC + 1H / Offset in second
int Display_backlight = 50;
const char *ssid = "LOCKDOWN";
const char *password = "thehammer";
//Set the red displays
int red_day = 05;
int red_month = 11;
int red_year = 2028;
int red_hour = 10;
int red_minute = 07;
//set the orange displays
int orange_day = 26;
int orange_month = 10;
int orange_year = 1985;
int orange_hour = 01;
int orange_minute = 24;
//=====================================================================
// Define NTP Client to get time
WiFiUDP ntpUDP;
NTPClient timeClient(ntpUDP, "pool.ntp.org", utcOffsetInSeconds);
TM1637Display green1(green_CLK, green1_DIO);
TM1637Display green2(green_CLK, green2_DIO);
TM1637Display green3(green_CLK, green3_DIO);
TM1637Display red1(red_CLK, red1_DIO);
TM1637Display red2(red_CLK, red2_DIO);
TM1637Display red3(red_CLK, red3_DIO);
TM1637Display orange1(orange_CLK, orange1_DIO);
TM1637Display orange2(orange_CLK, orange2_DIO);
TM1637Display orange3(orange_CLK, orange3_DIO);
void setup()
{
pinMode(32, OUTPUT);
pinMode(33, OUTPUT);
Serial.begin(115200);
Serial.println("\n Starting");
WiFi.begin(ssid, password);
while ( WiFi.status() != WL_CONNECTED ) {
delay ( 500 );
Serial.print ( "." );
}
timeClient.begin();
red1.setBrightness(Display_backlight);
red2.setBrightness(Display_backlight);
red3.setBrightness(Display_backlight);
green1.setBrightness(Display_backlight);
green2.setBrightness(Display_backlight);
green3.setBrightness(Display_backlight);
orange1.setBrightness(Display_backlight);
orange2.setBrightness(Display_backlight);
orange3.setBrightness(Display_backlight);
}
void loop()
{
timeClient.update();
Serial.print("Time: ");
Serial.println(timeClient.getFormattedTime());
unsigned long epochTime = timeClient.getEpochTime();
struct tm *ptm = gmtime ((time_t *)&epochTime);
int currentYear = ptm->tm_year+1900;
Serial.print("Year: ");
Serial.println(currentYear);
int monthDay = ptm->tm_mday;
Serial.print("Month day: ");
Serial.println(monthDay);
int currentMonth = ptm->tm_mon+1;
Serial.print("Month: ");
Serial.println(currentMonth);
red1.showNumberDecEx(red_month,0b01000000,true,2,0);
red1.showNumberDecEx(red_day,0b01000000,true,2,2);
red2.showNumberDecEx(red_year,0b00000000,true);
red3.showNumberDecEx(red_hour,0b01000000,true,2,0);
red3.showNumberDecEx(red_minute,0b01000000,true,2,2);
green1.showNumberDecEx(currentMonth,0b01000000,true,2,0);
green1.showNumberDecEx(monthDay,0b01000000,true,2,2);
green2.showNumberDecEx(currentYear,0b00000000,true);
green3.showNumberDecEx(timeClient.getHours(),0b01000000,true,2,0);
green3.showNumberDecEx(timeClient.getMinutes(),0b01000000,true,2,2);
orange1.showNumberDecEx(orange_month,0b01000000,true,2,0);
orange1.showNumberDecEx(orange_day,0b01000000,true,2,2);
orange2.showNumberDecEx(orange_year,0b00000000,true);
orange3.showNumberDecEx(orange_hour,0b01000000,true,2,0);
orange3.showNumberDecEx(orange_minute,0b01000000,true,2,2);
if(timeClient.getHours()>=13){
digitalWrite(greenAM,0);
digitalWrite(greenPM,1);}
else if(timeClient.getHours()==12){
digitalWrite(greenAM,0);
digitalWrite(greenPM,1);}
else{
digitalWrite(greenAM,1);
digitalWrite(greenPM,0);}
delay(20);
}
This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.