ADXL345 Not Working

hi! i got this error and the connection with the adxl its good
Invalid adxl345 id (got ca vs e5).

Invalid adxl345 id (got ca vs e5).
This is generally indicative of connection problems
(e.g. faulty wiring) or a faulty adxl345 chip.

beejayf•4/25/23, 3:59 PM

The wiring of the sensor is critical - mine was weird using untwisted cables and it fails to connect 80% of the time

beejayf•4/25/23, 4:00 PM

The longer the cable the more shielded cables or a tp network cable are recommended

beejayf•4/25/23, 4:04 PM

@chrizzar recommended the following: Twisted pair order for three twisted pairs:
GND+MISO
3.3V+MOSI
SCLK+CS
Note that unlike a cable shield, GND must be connected at both ends.

I she yet to try this but I am confident

Chrizzar•4/25/23, 4:05 PM

Cool cool, I hope it works out for you!

blacksmithforlife•4/25/23, 4:13 PM

I used a Cat6 cable and for each twisted pair I used one for ground and the other for one of the connections. That made it a rock solid connection and I have never had a ADXL issue

Chrizzar•4/25/23, 9:20 PM

Same

verbal-limeOP•4/26/23, 10:19 AM

okey. i will try with cat 6

verbal-limeOP•5/1/23, 4:32 PM

i used cat 6 cable. didnt work

verbal-limeOP•5/1/23, 4:32 PM

i will buy an new adxl to test

CCL54™i used cat 6 cable. didnt work

blacksmithforlife•5/1/23, 5:36 PM

How did you wire it up to the cat6 cable?

verbal-limeOP•5/1/23, 6:57 PM

with dupont connectors

beejayf•5/1/23, 7:03 PM

I also finished my cat6 based cable - as described above - can't get a connection either. I also think that I fried my ADXL...

CCL54™with dupont connectors

blacksmithforlife•5/1/23, 7:07 PM

did you take each twisted pair and use one of the wires for ground?
Pair 1 - Orange/White is 5V, Orange CS; Pair 2 - Green/White Ground, Green SDA; Pair 3 - Blue/White Ground, Blue SDO; Pair 4 - Brown/White Ground, Brown CLK.

endless-jade•5/1/23, 7:23 PM

Hello, can you please explain a bit wider what need to be dote to cables ? As i understand i need to take usual LAN cat6 cable. Have pairs twisted together and then i will need to solder all 5 White wires to GDN contact on both ends ?

verbal-limeOP•5/1/23, 7:44 PM

will test taht

CCL54™will test taht

blacksmithforlife•5/1/23, 7:47 PM

cat cable is able to transmit log distances because the ground is wrapped around the data lines. If you don't follow that then you will get cross talk, which the ADXL is extremely sensitive to

awake-maroon•5/1/23, 7:48 PM

I had this same issue when I first installed it. I found those same instructions that blacksmith posted before. Worked like a charm. It's not all four white wires though. Read it again. The orange/white and orange pair do not have a GND connection.

endless-jade•5/1/23, 7:52 PM

but the rest ( red, blue, yellow, green) should have GND ( white) soldered to gnd port on adxl and gnd connector to the board?

awake-maroon•5/1/23, 7:55 PM

network cables only have four pairs. Three of those pairs will have the white/(color) connected to ground. The forth pair is used for +5 and CS. Blacksmith lays it out completely in his post. I'm not sure what kind of cable you are using, as network cables always use brown,green,blue and orange with a corresponding white with a a colored stripe.

blacksmithforlife•5/1/23, 8:26 PM

I would also recommend soldering good silicone or PTFE wire and using a connector rated for moving parts (like jst-sm or molex). Then attach your CAT6 wire to the connector. the CAT6 wire will break eventually and you want to make it easy to replace it (unless you are good at desoldering. I am not, and it was a real pain to get it disconnected)

verbal-limeOP•5/2/23, 11:22 PM

the adxl was bad

verbal-limeOP•5/2/23, 11:22 PM

but now i have another problem

verbal-limeOP•5/2/23, 11:22 PM

verbal-limeOP•5/2/23, 11:22 PM

verbal-limeOP•5/2/23, 11:35 PM

verbal-limeOP•5/2/23, 11:35 PM

verbal-limeOP•5/24/23, 12:50 PM

so i need to put together all grounds?

CCL54™so i need to put together all grounds?

blacksmithforlife•5/24/23, 12:53 PM

correct

verbal-limeOP•5/24/23, 12:55 PM

okey im on it

Ppopular-magenta correct

verbal-limeOP•5/24/23, 1:00 PM

the ground cables can be not cat?

verbal-limeOP•5/24/23, 1:01 PM

like connect that 3 grounds cables to an single cable and that connect to ground

CCL54™the ground cables can be not cat?

blacksmithforlife•5/24/23, 1:04 PM

I don't understand, I listed all the cables within the CAT cable and what to use them for

verbal-limeOP•5/24/23, 1:04 PM

i mean, i got 3 grounds cable in cat 5e cable

verbal-limeOP•5/24/23, 1:05 PM

can i merge that cable with an single cable to fit duppont conector?

blacksmithforlife•5/24/23, 1:08 PM

yeah as long as they are all connected eventually

verbal-limeOP•5/24/23, 1:08 PM

okay

blacksmithforlife•5/24/23, 1:10 PM

I ran a very short length (like 7cm) of multistrain silicone lined wire to JST-SM connectors. That way I can easily replace the CAT cable in the future since its wiring doesn't seem to last as long as I would have hoped

verbal-limeOP•5/24/23, 1:11 PM

can i see that?

blacksmithforlife•5/24/23, 1:11 PM

sorry I am at work right now and can't get a picture

verbal-limeOP•5/24/23, 1:11 PM

Okay!

verbal-limeOP•5/24/23, 3:39 PM

Like that @blacksmithforlife