Suggestions for an Angle Sensor (one axis)

[_John_]

Hello,

I'm working on a project that I hope to start selling at some point. As part of its function, I need to know the pitch (one axis) of the device. I've been using an mpu6050 breakout board for this which is probably overkill but has worked great. I just found out the chip has been discontinued so I'm searching for something to replace it.

I'd like it to have:
Accuracy in the hundredths (0.0?) of a degree
Compatible with an ESP32
Speed at least 100hz
Inexpensive

I'd really appreciate any suggestions or advice on finding it.

Thanks!

 

[danadak]

https://www.digikey.com/en/products/filter/position-sensors/angle-linear-position-measuring/549?s=N4IgTCBcDaIIYDsDmAbApgAgM5oVg9gE4gC6AvkA

The search continues


Regards, Dana.

 

[rjenkinsgb]

Have a look at the TDK ICM-20948
That's an active product, not end-of-life.

 

[Papabravo]

How about a rotary encoder with quadrature outputs?

 

[_John_]

Thank you for the responses!

rjenkinsgb I checked out the ICM-20948 and it looks promising. A little on the pricey side but not out of the ballpark. I appreciate your suggestion.

Papabravo I'm looking for something that'll give me the angle in relation to gravity, not another object. I should have been more clear about that. Angle sensor might not be the correct term for it.

I'm wondering if I could use just a magnetometer or just a gyro or whatever since I only need one axis. I clearly need to do some more research, I don't know how the individual components work. You're right danadak, the search continues. lol

 

[alec_t]

Angle sensor might not be the correct term for it.

Look for 'mems inclinometer'.

 

[_John_]

alec_t Those were the exact words I needed to hear. Thank you!!

 

[Ian Rogers]

Specifically... 14 or 16 bit ones.. I use the MMA8451Q
I get mine from farnell but search for this.

Adafruit MMA8451 Accelerometer Breakout

The MMA8451 is a low-cost but high-precision digital accelerometer that uses I2C, with adjustable data rata and 'range' (+/-2/4/8).

learn.adafruit.com

Mine are only £6.. and are quite accurate. There is a library for XC8 and also one for the ardunio if you go that route.

 

[_John_]

Ian Rogers the MMA8451 looks really good. I'm showing $32 for the breakout at Farnell here in the US. It looks like you can get the IC for $1.17 from LCSC. Might be worth it for me to sort out the circuit and include it on my board. Thank you for letting me know about it!

 

[Ian Rogers]

Even the makers at Sparkfun sell at $7.28 They are listed on RS here in Blighty at £7.25.
I use these because its cheaper than making a board..

 

[_John_]

Ian Rogers Yeah, I see it being sold pretty cheaply elsewhere too. The more I look into it, the more I like it.

I think I'll have some PCBs printed even if it ends up costing more. I'd like to do it myself bc it'll ultimately be integrated with the circuit board of the device. That way I can make sure everything is working with the exact same parts and everything. Besides that, I'm looking for an excuse to use the reflow toaster oven I just built.

The circuit looks dead simple. I'm still very much a novice at creating PCBs. The only question I really have with this is if it's ok to use the same 3.3v for the Interface Voltage and the VDD? Or is there some reason they should be isolated from each other that I don't understand?

Here's the schematic I'm looking at from the datasheet:

 

[Ian Rogers]

The breakout board schematic is here

Adafruit MMA8451 Accelerometer Breakout

The MMA8451 is a low-cost but high-precision digital accelerometer that uses I2C, with adjustable data rata and 'range' (+/-2/4/8).

learn.adafruit.com

Note* I said Sparkfun.. The mma8451q is an Adafruit board, the sparkfun board is an mma8452q
Same pinout..

 

[_John_]

Cool! Thanks for the link. I did see it before but figured I'd draw up my own bc I'll be using an esp32. So I shouldn't need the voltage regulator or the level-shifting stuff. I did just take a second look though and see they do have interface and VDD tied together.

Hey man thanks again! You've really helped me sort this all out.

 

[bob4bvm]

Hello,

I'm working on a project that I hope to start selling at some point. As part of its function, I need to know the pitch (one axis) of the device. I've been using an mpu6050 breakout board for this which is probably overkill but has worked great. I just found out the chip has been discontinued so I'm searching for something to replace it.

I'd like it to have:
Accuracy in the hundredths (0.0?) of a degree
Compatible with an ESP32
Speed at least 100hz
Inexpensive

I'd really appreciate any suggestions or advice on finding it.

Thanks!

For similar requirements, i have usd a few of the inexpensive compltete inclinometer devices readily available on the market. I have paid from $6-9 for these devices, ready to go with backlit LCD display and accuracy to .01*
Grab a cheap one of these and see if you can integrate it into your project
For that price, i would not be reinventing the wheel

digital protractor - Temu

Best Budget digital protractor Sale. Find amazing deals on table saw digital angle gauge, digital bevel gauge and digital angle gauge harbor freight on Temu. Free shipping and free returns.

www.temu.com

Bob

 

[_John_]

Thanks bob4bvm . I sent off for some PBCs I drew up yesterday using the MMA8451. If I did everything correctly the problem should be solved. Thanks for the suggestion though!

 

[_John_]

Ian Rogers I finally received my boards, a month later, from JLCPCB. I thought I'd share the results.

The IC was difficult because I kept bridging the solder paste. The unit itself works well. I'm only getting about 50hz out of it though. I think it might be because I'm printing the results.

 

[Ian Rogers]

Cool!
What do you mean 50Hz? You mean 50 reads a second? The chip is good for 400khz
but sending ID then address, then resending address in read mode and reading..

5 bytes plus ACK stop start etc.. Say 6 bytes @ 400Khz continuously is 66.6Khz

50 times + outputting serial to read.. I know 9600 baud is 1ms so depending on the print line command

even if you send 3 bytes that will be @ 20ms (ish) + I2C read of 15us is 20.015mS so 50 of them will be about right.

 

[_John_]

Ian Rogers Yep, reads a second. I just switched the baud to 115200 and getting over 500. So everything is coming up roses! I actually have two projects I'm going to use these in now.