[SOLVED] ADS1x15 module is not really compatible with ADS1115

[espruino-discuss2]

Posted at 2022-08-05 by @yerpj

I just made a few experiments with an Adafruit 1115 breakout board along with the module EspruinoDocs/devices/ADS1X15.js. I compared the datasheet of ADS1115 and ADS1015 and it appears that the datarate config (DR[2:0]) is not the same. Thus, the ADS1X15.js is only valid for ADS1015. As long as the ADC type cannot be discovered at runtime, it may be better to make 2 modules instead of one, but it means renaming the js file. I don't know @gordon what would be the best way to go because renaming the current js module will break compatibility for those who currently use it.

Any hint?

Kind regards,

[gfwilliams]

Posted at 2022-08-09 by @gfwilliams

Thanks for figuring that out!

Is everything else basically the same though? So as far as I can see the ADS1015 would run at 1600 samples/second by default while the ADS1115 is only 128 (which was the default in both cases) - but everything should still work ok?

It's frustrating not having an I2C WHOAMI register! I thought pretty much every device had them now.

I'd have said duplicating everything just for that might be overkill - what about extending the .connect function with an options object:

var ads = require("ADS1X15").connect(I2C1, { part:"ads1115"});

So then anyone using this already would have it work fine, but it could easily support the ADS1115

[espruino-discuss2]

Posted at 2022-08-23 by @yerpj

Thank you @gordon. I tried to implement this feature according to your recommendation and made a pull request here: espruino/EspruinoDocs#665

However, when testing, I got this error

Uncaught Error: Function "connect" not found!
 at line 96 col 26 in ADS1X15
function ADS1X15(i2c,opts={part:"ads1015"}) {
                         ^
 at line 198 col 30
    ads = require("ADS1X15").connect(i2c,{part:"ads1115"});
                             ^
in function "onInit" called from line 212 col 8
onInit();

It is most probably a very noob, basic javascript error. Could you help me figure out what's going wrong with the way I made the change?

[gfwilliams]

Posted at 2022-08-24 by @gfwilliams

I think it's that you're using 'default arguments' which is a newish JS feature that Espruino doesn't support yet.

I've just merged your PR and hopefully tweaked it though

[espruino-discuss2]

Posted at 2022-08-24 by @yerpj

Thank you very much, I must say that I didn't look so deep into other modules to check how optional parameters were handled.
Anyway I just tested the new version of the ADS1X15 module and it works well with an ads1115. Thank you for your incredibly fast actions!