hi,
does someone know a RTC by i2c, but not addr 0x68 (perhaps switchable)?
(0x68 conflicts with MPU6050, and for MPU cross-platform compatibility I actually would not like to change the MPU addr; but IIUC, both DS3231 and DS1307 are at 0x68 and both are not switchable, whilst DS1302 is not driven by i2c at all)
so is there another RTC device available that fits?
Would DS3234 on SPI work?
Either that, or add an I2C mux chip.
the first one I found when I searched:
MCP7840N is at 0x6F
CrossRoads:
Would DS3234 on SPI work?
Either that, or add an I2C mux chip.
CrossRoards is spot on, but there are a few more good options.
The MPU-6050 is noisy and old.
The MPU-9250 in SPI mode is better and solves the problem.
What is wrong with a MPU-6050 or MPU-9250 with address 0x69 ? I don't understand the cross-platform compatibility.
Please use one of the DS323x series, they are accurate and cause so much less trouble than the older ones with a seperate crystal.
Without mux chip, it is possible to use the DS3231 with a software I2C library on any digital pins.
An other RTC chip might not have a good library for it.
At mouser.com I found 308 RTC chips ! Stick with the DS323x series and don't use an other one. I have warned you 
Thanks to all!
Geek Emeritus: DS3231 RTC is at 0x68, as stated ( I have that thing)
CrossRoads: SPI is no option unfortunately, it makes my SPI TFT slower (should run at at least 30MHz on my M4 SAMD51 actually, if possible) and above all: I have no singe free CS pin available
wvmarle: MCP7840N is not found on Amazon or Ebay and I also can't find any Arduino MCP7840N libs unfortunately
Koepel: MPU6050 is indispensible and I would like to keep the i2c default settings
and i2cmux would make my MPU6050 slower and no longer accessable with my DMP6 lib without huge changes I'm afraid
So I'm afraid another RTC would be needed than the ones mentioned above 
dsyleixa:
wvmarle: MCP7840N is not found on Amazon or Ebay and I also can't find any Arduino MCP7840N libs unfortunately
Oops, typo.
MCP7940N is the correct number.
Arduino library exists; I've contributed a few little bits to it myself 
wvmarle:
Oops, typo.
MCP7940N is the correct number.
Arduino library exists; I've contributed a few little bits to it myself
is there a brakeout board available with just 4 connector pins (V,G,SDA,SCL) and a on-board buffer battery like for DS3231?
Don't know - never used them on breakout board...
Geek Emeritus: DS3231 RTC is at 0x68, as stated ( I have that thing)
harrumph ( hairy eyeball )
look at that image. on the bottom right you have A0 A1 A2
mouse over that. you will see that those are jumpers.
If you bridge the contacts at A0, you increase the address by 1.
If you bridge the contacts at A1, you increase the address by 2.
If you bridge the contacts at A2, you increase the address by 4.
giving you 7 additional addresses to choose from
We spend most of our life scrolling through datasheets. Which pins are A0, A1 and A2 for the DS3231 chip ?
@dsyleixa, there is also the ISL1208, it uses 0x6F. But I strongly advise one of the DS323x.
Which pins are A0, A1 and A2 for the DS3231 chip ?
not pins. jumpers. exactly like the jumpers that let you set the address of an I2C LCD module, or a weather sensor
bottom right of the image in the link
Since you don't get the hints, I will tell you. Those are I2C address jumpers for the EEPROM (AT24C32) which is also on the board. The DS3231 RTC has a fixed I2C address of 0x68.
oooops - I missed the last post.
so no i2c address jumpers for DS3231 though, regrettably?
dsyleixa:
oooops - I missed the last post.
so no i2c address jumpers for DS3231 though, regrettably?
I was talking to Geek Emeritus, who probably did not read as many datasheets as some of us.
@dsyleixa, you already wrote "DS3231 RTC is at 0x68, as stated ( I have that thing)". That is correct.
What are you going to do ?
Did you use all the pins ? So you don't have two digital pins for a software I2C bus ?
Another RTC without a proven library is a risk.
The MPU-6050 at 0x69 can't be so hard, or is it ?
no, I have the Feather M4 and the Feather ESP32, both are incredibly lacking of GPIOs (e.g., M4 is missing 2,3,7,8), and 4 GPIOs are already used for TFT, Touch, and SD. The rest is also already in use.
OTOH often the MPU libs (which I am using for many different apps) are hard-coded to 0x68.
I also have a CMPS11 and a CMPS12 but they are far too expensive for everyday's use, and sometimes the Compass is even obstructive and a hindrance in noisy magnetic environments.
Of course, if f there will be no other (cheap) way then of course I'll have to change the MPU addr
1st I'll now check the ISL1208, thanks....!
(edit: no vendor found yet, and neither an Arduino lib unfortunately)
