OpenMarine

(2020-11-14, 12:50 PM)PaddyB Wrote: [ -> ]

(2020-11-14, 11:25 AM)affinite Wrote: [ -> ]1) Can you draw a heavy load through an external shunt in parallel with the onboard without blowing the onboard shunt?
If the load is drawing say 50A (e.g. battery charging) doesn't 50A get pulled through the (parallel) shunts thus destroying the (3.2A) on-board shunt?
I know the simple answer is to remove the on-board shunt but I note above that Paddy just "piggy-backed" the INA219 onto the external shunt - I'd like to understand why that didn't result in Blue smoke !

Yes, it's fine on an external  shunt like 50mA/100A.
The sense resistor in the ina219 is massive compared to the external shunt so next to no current goes through it. It would be more 'proper' to remove the internal sense resister on the ina219 but I didn't bother (yet) , just calibrated by hand to measured current when setting up.

Thanks that make sense

Quote:
Haven't touched this for a while, and forgot I even uploaded this 

Might work, give it a go 

https://github.com/boatybits/ConstantCurrent

Sorry for posting to old thread. I'm thinking about giving this a go, but which .ino file I should use? There are multiple that all seem to contain relevant bits. Bear with me, I'm new to all this. But coming along quite nicely!

Try this - click on "code" then dowenload the zip, unzip into a folder then with arduino IDE open constantCurrent.ino and should work. Might work..

(2021-05-09, 09:20 PM)PaddyB Wrote: [ -> ]Try this - click on "code" then dowenload the zip, unzip into a folder then with arduino IDE open constantCurrent.ino and should work. Might work..

Ciao PaddyB, is your project stopped? (https://github.com/boatybits/boatymonpy). 

I have three / four cards left over to me if anyone is interested in having one, come forward. I've finished one, but as an incompetent, I can't go on.
 More simple instructions would be needed to load the software and how to make the various connections ... in any case, good wind to everyone, always! 

(2021-05-10, 09:49 AM)Max1947 Wrote: [ -> ]

(2021-05-09, 09:20 PM)PaddyB Wrote: [ -> ]Try this - click on "code" then dowenload the zip, unzip into a folder then with arduino IDE open constantCurrent.ino and should work. Might work..

Ciao PaddyB, is your project stopped? (https://github.com/boatybits/boatymonpy). 

I have three / four cards left over to me if anyone is interested in having one, come forward. I've finished one, but as an incompetent, I can't go on.
 More simple instructions would be needed to load the software and how to make the various connections ... in any case, good wind to everyone, always! 

This is still getting fiddled with, I've just updated the beta2 branch to the latest code. 

Slowly I'm looking at getting new boards made, maybe with an esp32 prosoldered on but definitely with rj45 sockets and little breakout boards so the wiring can be done much more tidy using off the shelf network cables rather than get everything back to the board. 

I just started a very brief wiki on GIT about getting the code onto the ESP > https://github.com/boatybits/boatymonpy/wiki
Various settings can be changed in the config.py file. 

Sorry, all a bit brief but the boat jobs list is never ending so better get on with that ?

Thanks for showing some interest, do report back how you get on, good luck!

(2021-05-09, 09:20 PM)PaddyB Wrote: [ -> ]Try this - click on "code" then dowenload the zip, unzip into a folder then with arduino IDE open constantCurrent.ino and should work. Might work..

cool beans, I give it a go when my chips arrive.

So this is really old thread and I forgot about this, but went on with it. Apparently stuff has changed since 2019/2021 and when I try to compile this I get:

In file included /ArduinoINA219/INA219.h:213:13: error: expected ',' or '...' before 'bool'
  213 |            bool stop = true // false if the i2c bus should not be released.
      |            ^~~~
In file included from /ConstantCurrent/variables.h:42:14: error: 'D0' was not declared in this scope; did you mean 'A0'?
  42 | int pwmPin = D0;
      |              ^~
      |              A0

exit status 1

Compilation error: 'D0' was not declared in this scope; did you mean 'A0'?

Anyone has any guesses what' going on?

EDIT: Used 5 year old github repo and managed to get rid of that mistake, D0-A0 is still a mystery. When changed, it passes debug.