1
\$\begingroup\$

I try to run an accelerometer (Data sheet) with this library (link). Bus: I2C and Microcontroller adafruit-feather-m0-adalogger (link) is used.

If I wire the accelerometer to the muhC, I just get zeros for the acceleration values, but reasonable values for temperature. So I think that pull up resitors are needed. Correct?

I checked the data sheet of the accelerometer (page 103) for more information. But I still don't know which resistors to use. Could you help me?

Thanks!

wiring

\$\endgroup\$
13
  • 1
    \$\begingroup\$ ok, thanks! Then I will check the configuration. @tlfong01 There's no tutorial for this acc. You think it won't work? \$\endgroup\$ – Lorenzooo Aug 5 '20 at 8:58
  • 1
    \$\begingroup\$ @tlfong01 Again, thanks for your response! I'm using the Feather M0 with arduino IDE link \$\endgroup\$ – Lorenzooo Aug 5 '20 at 10:02
  • 1
    \$\begingroup\$ @tlfong01 this would be possible even if curcuitpython were used, one can always perform the I2C operations directly. Your comments here are not particularly accurate. While some of the Adafruit M0 products may be able to run circuitpython it is neither their original nor primary purpose. It is also extensible. \$\endgroup\$ – Chris Stratton Aug 5 '20 at 11:45
  • 1
    \$\begingroup\$ As the accelerometer is SPI/I2C dual capable and the board supports multiple addresses you need to make sure it is configured for I2C and that the code is using the address in effect. Is your code appropriate to this accelerometer? \$\endgroup\$ – Chris Stratton Aug 5 '20 at 11:51
  • 1
    \$\begingroup\$ @tlfong01 stop posting such uninformed falsehoods! Adafruit has most definitely NOT discontinued Arduino support. It does not really seem that you have much knowledge to contribute to the question here. \$\endgroup\$ – Chris Stratton Aug 5 '20 at 12:14
2
\$\begingroup\$

If you look at the schematics of the module, it already has 4k7 pull-ups to 3.3V.

So it does not need any external pull-ups.

And don't know what "5V or 3.3V" means in your picture, as the module works only on 3.3V and 5V will damage it.

Most likely the library does not initialize the chip correctly or the I2C address is wrong.

\$\endgroup\$
4
  • \$\begingroup\$ Thanks! Yes, you're right. I should have written "3.3V" instead of "5V or 3.3V". \$\endgroup\$ – Lorenzooo Aug 5 '20 at 9:01
  • \$\begingroup\$ How to I get to know the correct I2C adress? \$\endgroup\$ – Lorenzooo Aug 5 '20 at 10:06
  • \$\begingroup\$ By reading the user manual of the module you have, or the chip datasheet. If the temperature sensing part and accelerometer are used via the same I2C address, then the address is correct. Some chips may use multiple I2C addresses, but I do not know if this chip does. \$\endgroup\$ – Justme Aug 5 '20 at 10:52
  • \$\begingroup\$ Thanks! I took a look in the breakout board data sheet (link): Label: JP; Name: ADDR SEL; Default: Left; Description: I2C address LSB selection: left position 0, right position 1. Is this the adress I need? \$\endgroup\$ – Lorenzooo Aug 5 '20 at 13:13

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.