[SOLVED] Unknow pin on a popular DS1307 board

I wonder if someone can shed some light over this "DS" pin on a popular DS1307 breakout board:

Take a look at the pictures. The DS pin seems to be connected to an unpopulated pad (resistor?) that is connected to a transistor-looking pattern. Does anyone know what this pin does?

Thanks.

Take a look at the pictures.

It said:-

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Reference #18.a1ff4317.1469654009.530137a9

The DS pin seems to be connected to an unpopulated pad

I'll bet the DS pin does nothing.

Hi,
Sainsmart have the same device.

It has a documents file.

Tom... :slight_smile:

I just looked through all of those documents and couldn’t find an answer.

The letters “ds” are used in the demo example…

#include <OneWire.h>
#include <WProgram.h>
/* DS18S20 Temperature chip i/o */
#include <Wire.h>
#include <DS1307.h>

OneWire ds(3); // on pin 3
byte Tdata[12];
int rtc[7];
//int deviceaddress = 0x50;
int deviceaddress = 0x52;
int addr=0; //first address
int lastTime;
byte saveDate[6];
boolean full=false;
int ledPin = 13;
int outpin=3;
int val = 0; // variable to store the read value

There’s more to that code I can post if someone thinks it might help, but I don’t even know if the “ds” in the code and the “ds” on the board are related. I simply don’t have enough experience with coding.

Trace out the circuit - what is the other end of that resistor-like thing, and the other pins on the transistor-like thing connected to? That - and the datasheet for the parts that are on the board - will probably point you in the right direction.

Some of the modules were designed to have a DS18B20/DS18S20 chip on board, similar to the added eeprom. The DS is the one wire pin connection. See the empty three pin area on this image.

Great! Ds18 series one wire temperature probe. Makes sense. Thanks.

Here’s a schematic:-
DS1307_24_C32.jpg

Thanks again! All EEPROM address pins are grounded. Looks like 3K3 pullup for I2C. I hope after adding this one and an ADS1115 breakout (10K pullup) and a 10DEF board (unknown pullup), the I2C pullup won't be too small :slight_smile:

liudr:
I hope after adding this one and an ADS1115 breakout (10K pullup) and a 10DEF board (unknown pullup), the I2C pullup won't be too small :slight_smile:

Yeah. I hate the fact that so many I2C-based boards have on-board pullups. :frowning: