i2c MPR121, Need help trouble shooting whats wrong...

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Mangy_Dog
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Re: i2c MPR121, Need help trouble shooting whats wrong...

Post by Mangy_Dog »

Deffo 5B, but i wrote a sketch to check each address one after the other, and say if theres no response.
I also checked my old build version, and i used a 10k pullup on that address too...
Just a dogs body developer, mostly making props and stuff...
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Mangy_Dog
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Re: i2c MPR121, Need help trouble shooting whats wrong...

Post by Mangy_Dog »

Good news bad news........
Good news, got the chip talking by having the pullups hacked into a scratched off bit of trace near the chip...

Bad news. I have no choice but to do a PCB respin now.... Sighs. Well im not going to get this to the guy before Christmas :/

And its yet another bit of wasted money on my part ordering new pcbs.
Just a dogs body developer, mostly making props and stuff...
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Mangy_Dog
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Re: i2c MPR121, Need help trouble shooting whats wrong...

Post by Mangy_Dog »

Well new PCBS came in a few weeks ago and i finally got round to soldering them up... And i kinda have i2c working.
Trouble is ive had to use this https://github.com/Tinwelint78/Adafruit_MPR121_STM32

Which uses softwire. I tried swapping out softwire for wire so it used hardware i2c. But thats not working. The normal version of this library uses arduino atmega wire calls. But that didnt work either. I dont know if hardware i2c is still broken or if im just doing it wrong, ive not done a huge amount of i2c tbh.

Like I say this softwire version is working. And hardware wire with scanner can find my cap touch chip. But I cant seem to use the normal library with it.
Id rather use the hardware i2c as it would take less cpu time and im already pushing my little f103 to its limits I feel with all the other rtos stuff going on.
Just a dogs body developer, mostly making props and stuff...
stevestrong
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Re: i2c MPR121, Need help trouble shooting whats wrong...

Post by stevestrong »

I would recommend to try the lb on a bluepill using (Hard)Wire lib so see if it works with MPR module.
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